ca alys s
A icle
Cobal Based Ca alys s on Alkali-Ac i a ed Zeoli e
Foams o N2O Decomposi ion
Zdenˇek Tišle 1, Anna Klego á2, Eliška S obodo á1,* , Jan Ša ᡠ1, Ka eˇ ina S ejco á1,
Jan Kohou 1, S anisla Šlang 3, Ka eˇ ina Pacul o á2, Daily Rod íguez-Pad ón4and
Roman Bulánek 5
1Unipe ol Cen e o Resea ch and Educa ion, a.s, A eál Chempa k 2838, Záluží1,
436 70 Li íno , Czech Republic; [email p o ec ed] (Z.T.); [email p o ec ed] (J.Š.);
ka e ina.s ejco a@unic e.cz (K.S.); [email p o ec ed] (J.K.)
2Ins i u e o En i onmen al Technology, VSB-Technical Uni e si y o Os a a, 17. lis opadu 15/2172,
708 00 Os a a, Czech Republic; [email p o ec ed] (A.K.); [email p o ec ed] (K.P.)
3Cen e o Ma e ials and Nano echnologies, Facul y o Chemical Technology,
Uni e si y o Pa dubice Nam. Cs. Legii, 530 02 Pa dubice, Czech Republic; s anisla [email p o ec ed]
4Depa amen o de Química O gánica, Campus de Rabanales, Uni e sidad de Có doba,
Edi icio Ma ie Cu ie (C-3), C a Nnal IV-A, Km 396, E14014 Co doba, Spain; [email p o ec ed]
5Depa men o Physical Chemis y, Facul y o Chemical Technology, Uni e si y Pa dubice, S uden ská573,
532 10 Pa dubice, Czech Republic; [email p o ec ed]
*Co espondence: eliska.s obodo a@unic e.cz
Recei ed: 16 Oc obe 2020; Accep ed: 27 No embe 2020; Published: 30 No embe 2020


Abs ac :
In his wo k, we s udied he e ec o alkali-ac i a ed zeoli e oams modi ica ions on
p ope ies and ca aly ic ac i i y o cobal phases in he p ocess o ca aly ic decomposi ion o N
2
O.
The zeoli e oam suppo s we e p epa ed by alkali ac i a ion o na u al zeoli e ollowed by acid
leaching and ion exchange. The cobal ca alys s we e syn hesised by a di e en deposi ion echnique
(di ec ion exchange (DIE) and incipien we ness imp egna ion (IWI) me hod o cobal on zeoli e
oams. Fo compa ison, ca alys s on selec ed suppo s we e p epa ed and he p ope ies o all we e
compa ed in ca aly ic es s in he pelle o m and as c ushed ca alys s o de e mine he e ec o
in e nal di usion. The ca alys s and suppo s we e in de ail cha ac e ized by a a ie y o echniques.
The ca alys ac i i y s ongly depended on he s uc u e o suppo and syn hesis p ocedu e o a cobal
ca alys . Ion exchange me hod p o ided ac i e phase wi h highe su ace a eas and si es wi h be e
educibili y, bo h o hese ac o s con ibu ed o highe N
2
O con e sions o mo e han 80% a 450
◦
C.
A la ge in luence can also be a ibu ed o he p esence o alkali me als, in pa icula , po assium,
which esul ed in a modi ica ion o elec onic and acid base p ope ies o he cobal oxide phase on
he ca alys su ace. The p omo ional e ec o po assium is be e educibili y o cobal species.
Keywo ds:
na u alzeoli e;clinop iloli e;zeoli e oam;alkaliac i a ion;cobal ca alys ;N
2
Odecomposi ion
1. In oduc ion
The alkali-ac i a ed ma e ials ha e p ope ies e y simila o zeoli es bu do no o m c ys alline
s uc u es. These ma e ials can be p epa ed by ac i a ing a a ie y o aluminosilica e componen s.
Raw ma e ials o he p epa a ion o hese ma e ials, e.g., na u al zeoli es, mos o en occu as compac
ine-g ained ocks o med by sedimen a y o olcanic ac i i y, whose main componen is zeoli e
clinop iloli e, belonging o he g oup o heulandi e, accompanied by mine als om he g oup o
eldspa s, clays and mica. Due o hei p ope ies, na u al zeoli es a e widely used as so ben s o wa e
pu i ica ion (Cs
+
, Rb
+
and NH
4+
) o gases (NH
3
) [
1
,
2
]. They do no ha e sui able p ope ies o use in
ca alysis, which equi es hei modi ica ion by p ocesses such as dealumina ion [
3
,
4
], desilica ion o
Ca alys s 2020,10, 1398; doi:10.3390/ca al10121398 www.mdpi.com/jou nal/ca alys s
Ca alys s 2020,10, 1398 2 o 21
ion exchange [
5
]. These modi ica ions imp o e he p ope ies in he desi ed di ec ion, e.g., inc ease he
speci ic su ace a ea o educe he con en o accompanying elemen s (Fe, K, Na, Ca and Mg). The same
modi ica ion p ocedu es can be used o modi y he p ope ies o zeoli e oams which, in addi ion o
almos any desi ed shape (pelle s, blocks, c umb) and mac opo osi y no p esen in he o iginal zeoli e
ma e ial, impa he desi ed p ope ies o he zeoli e ma e ial. Mac opo osi y is ad an ageous no only
o di usion easons bu also o s uc u al easons, as his ma e ial educes weigh o ca alys /so p ion
bed and hus he complexi y o he equipmen and i s obus ness equi emen s [6].
Alkali-ac i a ion o na u al zeoli e p oduces a oam ma e ial consis ing o he o iginal zeoli e
(clinop iloli e) s uc u e and he N/K-A-S-H binde ma ix (Na
2
O/K
2
O-Al
2
O
3
-SiO
2
-H
2
O) ha binds
he indi idual g ains o aluminosilica e componen . This binde ma ix is o med by he eac ion o
he alkaline ac i a o wi h an aluminosilica e (na u al zeoli e). These ma e ials wi h he addi ional
mac opo ous s uc u e a e p epa ed by alkaline ac i a ion o na u al zeoli e wi h a mixed ac i a o
based on po assium hyd oxide and sodium silica e. The mac opo ous s uc u e is ob ained by oaming
an ac i a ed mix u e o me al powde s (Al, Mg, Zn) [
6
–
8
], solu ions con aining hyd ogen pe oxide [
8
,
9
],
silica ume o silicon powde [
10
,
11
]. Subsequen eac ion o hese componen s wi h he alkaline
ac i a o esul s in he e olu ion o a gas which oams he ac i a ed mix u e.
The oaming o he alkali-ac i a ed mix u e and ollowing pos -syn hesis modi ica ion o p epa ed
ma e ials e.g., by acid leaching c ea e a well pe meable oam s uc u e o low densi y in which mic o-,
meso-andmac opo esa ep esen . Acidleachingiso enused o pos -syn hesismodi ica iono zeoli es
o emo e amewo k aluminium and, in he case o alkali-ac i a ed ma e ials, o he accompanying
elemen s (K, Na, Ca, Fe, Mg), p esen ed in he basic zeoli e g ains o binde ma ix. This leaching o
he ma e ial c ea es addi ional po osi y, which is impo an o he easie pe meabili y o oams [
8
].
The second op ion o pos -syn hesis modi ica ion o oams is he ion exchange (IE). This me hod is
widely used o zeoli es and due o he simila i y o alkali-ac i a ed ma e ials, his echnique can also
be used o he emo ing o Na and K ions o exchanging ano he ca ion [8].
Ni ous oxide (N
2
O) is conside ed as an impo an pollu an con ibu ing o he g eenhouse e ec
e en hough i is no he majo con ibu o . Howe e , unlike he main con ibu o s (CO
2
and CH
4
), i is
much mo e e icien g eenhouse gas [
12
]. The la ges indus ial sou ces o N
2
O emissions a e was e
gases om ni ic acid p oduc ion plan s in a global amoun o mo e han 400 k o N
2
O pe yea [
12
].
Ca aly ic decomposi ion o N
2
O can be pe o med di ec ly in he NH
3
bu ne ( empe a u e a ound
900
◦
C, ca alys s based on oxides, spinels and pe o ski e ma e ials) o behind he bu ne , when he
gas empe a u e is only 250–500
◦
C. In addi ion o he possibili y o he mal decomposi ion o N
2
O
(by inc easing he gas empe a u e o 750–1000
◦
C), non-selec i e o selec i e ca aly ic educ ion o
N2O ( equi ing he addi ion o educing agen s such as hyd ogen, na u al gas, LPG, NH3, e c.) is he
mos economically ad an ageous di ec ca aly ic decomposi ion o N
2
O. The low- empe a u e ca aly ic
decomposi ion o N
2
O (up o 450
◦
C) o ni ogen and oxygen o e s an a ac i e way o dec ease N
2
O
emissions in ail gas om ni ic acid p oduc ion plan s. Resul s om a numbe o ca aly ic sys ems
ha e been published. Fo example, ca alys s based on ansi ion me als (Cu, Co, Ni, Fe) o ca alys s
based on p ecious me als (Rh, Ru, Pd) using a ious ca alys suppo s (ZnO, CeO
2
, Al
2
O
3
, TiO
2
, Z O
2
,
zeoli es, hyd o alci es and pe o ski es). This s udy is ocused on cobal -based ca alys s ha show
excellen ca aly ic ac i i ies a low empe a u e (≤450 ◦C) in he decomposi ion o N2O [12–30].
Ca alys s based on syn he ic zeoli es a e success ully used and s udied in a numbe o ca aly ic
applica ions including ca aly ic decomposi ion o ni ous oxide. Syn he ic cobal modi ied zeoli es
(Be a, Y, ZSM-5, e c.) [
31
], e en ually modi ied by o he me als like i on o coppe [
32
], we e o en
s udied. These ca alys s show e y good esul s in he ca aly ic decomposi ion o N
2
O, con e sions
each up o 100% a 425 ◦C and gi en expe imen al condi ions [33]. The disad an age in compa ison
wi h na u al zeoli es and ma e ials o med he e om, o example, alkali-ac i a ed oams, is in
pa icula ha hei syn hesis is ela i ely ime-consuming and economically demanding. On he o he
hand, he use o leached modi ied na u al zeoli e wi h subsequen ion exchange (IE) encoun e s some
limi a ions, such as unsa is ac o y ex u al p ope ies o limi ed IE capaci y [34].
Ca alys s 2020,10, 1398 3 o 21
In addi ion o zeoli e ca alys s, o he ypes o ca alys s p epa ed, o example, by imp egna ion
o o he suppo s, p ecipi a ed ca alys s o ca alys s p epa ed by o he echniques based on he
p esence o spinel phases o cobal o mixed Co-Mn-Al phases a e s udied o ca aly ic N
2
O
decomposi ion
[11,24,27,35]
. Modi ica ion o he cobal spinels wi h a small amoun o alkali me als
signi ican ly inc eases he ac i i y o he ca alys , alkali me al p omo e lowe s he wo k unc ion o he
cobal spinel acili a ing edox p ocesses ha occu be ween he ca alys su ace and he eac ion oxygen
in e media esp oduced du ing he N
2
Odecomposi ionleading o hesigni ican inc easein heca aly ic
ac i i y[
14
,
17
,
23
,
27
,
35
–
38
]. Syn hesiscondi ionso heCospineloxidecouldsigni ican lya ec ca aly ic
p ope ies. Di e en me hods we e desc ibed o he p epa a ion o cobal oxide-based ca alys s:
(co)-p ecipi a ion om cobal ni a e solu ion using di e en p ecipi a ion agen s like Na
2
CO
3
[
20
,
39
],
K
2
CO
3
[
40
,
41
], (NH
4
)
2
CO
3
[
16
], KOH [
42
] and NH
3·
H
2
O, NaOH [
39
], by he mal ea men o cobal
ni a e [
24
,
43
,
44
], cobal ca bona e [
14
,
24
] o cobal benzoa e-dihyd azina e complex [
45
] and by
solu ion combus ion syn hesis om cobal ni a e and u ea [
43
]. Equally, he deposi ion o ac i e phase
on sui able suppo has a signi ican impac . The e o e, he selec ion o sui able suppo could lead o
mo e e icien u iliza ion o ac i e phase. I is achie ed by applying a hin ac i e laye o he suppo
ma e ial. Suppo ed cobal oxide N
2
O ca alys s we e s udied mainly on di e en monoli hs [
46
–
49
],
sie es [32,50], able s, pelle s o ex uda es [29,51] and ce amic oams [52].
The wo k aims o p epa e cobal ca alys s based on alkali-ac i a ed zeoli e oams and de e mine
he in luence o ca alys suppo modi ica ions and cobal oxide loading me hod on physic-chemical
p ope ies and ca aly ic ac i i y in N
2
O decomposi ion. Acid leaching and ion exchange o alkali
ac i a ed zeoli e oam (AZF) we e used o p epa e ca alys suppo s, which we e subsequen ly
imp egna ed wi h cobal ni a e, and a e annealing, cobal oxide ca alys s we e ob ained. The same
me hod was used o p epa e compa a i e ca alys s using alumina as a suppo . The e ec o di e en
p epa a ion on he p ope ies o he ac i e phase was s udied on ca alys s p epa ed by di ec ion
exchange (DIE) o basic alkali ac i a ed zeoli e oam, as well as he p omo ional e ec o manganese
in Co ca alys in ca aly ic decomposi ion o N
2
O. The e ec o Mn, was moni o ed in ou s udy
because CoMnAl HTC 4:1:1 ca alys s a e o en epo ed o ha e e y good esul s.S udied ca aly ic
ma e ials showed signi ican di e ences in he ex u al p ope ies and chemical composi ion o he
ac i e phase esul ing in signi ican di e ences in ac i i y depending on he chosen modi ica ion
me hod. All ca alys s we e cha ac e ized by a ious ins umen al echniques and es ed in he N
2
O
ca aly ic decomposi ion in ine gas. The ob ained esul s showed he u he possible use o ca alys s
based on alkali-ac i a ed zeoli e oams in ca aly ic applica ions. In he ield o indus ial ca alysis,
in addi ion o he ca aly ic esul s, he ease o syn hesis, a o dabili y and he p ice o he ca alys s used
a e also impo an , and he e o e, hese ma e ials ha e a lo o o e .
2. Resul s and Discussion
2.1. Cha ac e isa ion o he Ca alys s and Suppo s
Zeoli e oam used as ca alys suppo was p epa ed by oaming o alkali-ac i a ed na u al zeoli e
mix u e. Ob ained po ous solid oam ma e ial was pos -syn hesis modi ied (i) by acid leaching wi h
3M HCl o (ii) by ion-exchange ea men using 1M NH4NO3.
As-p epa ed zeoli e oam (AA-S, Table 1) had a highe alkali me als con en han na u al zeoli es
due o he use o mixed alkaline ac i a o KOH +Na
2
SiO
3
. Chemical composi ion o Al
2
O
3
can be
seen in Appendix ATable A1. A pa o he alkaline ac i a o occu ed in a o m o mixed Na/K silica e,
which can be seen in images om SEM equipped wi h EDS analyse as a lea -like pa icles (Figu e 1).
Ion-exchange ea men o AA-S sample using NH
4
NO
3
solu ion (AA-N) educed p edominan ly
con en o K and Na ca ions. A pa o K
+
and Na
+
ions was in “unchangeable posi ions” apped
inside o he zeoli e and/o o he aluminosilica es amewo k [
4
,
8
]. Resul s o chemical composi ion
analysis (Table 1) showed a no iceable e ec o HCl leaching (AA-D). HCl mos ly educed he alkali
Ca alys s 2020,10, 1398 4 o 21
con en (K, Na) in addi ion o o he elemen s (Fe, Ca, Mg and especially Al), which esul ed in o highe
Si/Al a io (up o 11.8 om he o iginal 5.8).
Table 1. Chemical composi ion and speci ic su ace a ea o ca alys s and zeoli e oam suppo s.
Sample Chemical Composi ion (w .%) Si/Al Ra io
(mol/mol) Co/AM *
Ra io
SSA **
(m2/g)
Si Al K Na Ca Fe Co Mn
AA-S 33.4
5.5 7.2 2.9 2.3 0.9
- - 5.8 - 15.0
AA-N 37.8
6.3 1.6 0.3 1.7 1.1
- - 5.8 - 23.4
AA-D 42.0
3.4 1.1 0.2 0.5 0.7
- - 11.8 - 111.7
AA-S-Co 30.5
5.1 6.6 2.6 2.1 0.9 6.4
- 5.7 0.4 13.5
AA-N-Co 35.0
6.0 1.4 0.2 1.6 1.0 5.7
- 5.6 2.1 27.7
AA-D-Co 38.7
3.5 1.1 0.2 0.4 0.7 5.4
- 10.6 2.5 49.9
AA-IE-Co 32.0
5.2 4.1 0.5 1.7 0.9 6.3
- 5.9 0.9 115.8
AA-IE-CoMn 31.9
5.2 4.2 0.5 1.7 0.9 5.4 0.8
5.9 0.7 118.6
* AM =alkali me als (Na +K), ** SSA =speci ic su ace a ea (BET).
Ca alys s 2020, 10, x FOR PEER REVIEW 4 o 22
Na) in addi ion o o he elemen s (Fe, Ca, Mg and especially Al), which esul ed in o highe Si/Al a io
(up o 11.8 om he o iginal 5.8).
Figu e 1. Mac opo ous s uc u e o zeoli e oam AA-S (a), c ys alline Na/K silica e (whi e a ow) in AA-
S (b) and lea es o Na/K silica es in AA-S-Co ca alys (c).
Table 1. Chemical composi ion and speci ic su ace a ea o ca alys s and zeoli e oam suppo s.
Sample
Chemical Composi ion (w .%)
Si/Al Ra io
(mol/mol)
Co/AM * Ra io
SSA **
(m2/g)
Si
Al
K
Na
Ca
Fe
Co
Mn
AA-S
33.4
5.5
7.2
2.9
2.3
0.9
-
-
5.8
-
15.0
AA-N
37.8
6.3
1.6
0.3
1.7
1.1
-
-
5.8
-
23.4
AA-D
42.0
3.4
1.1
0.2
0.5
0.7
-
-
11.8
-
111.7
AA-S-Co
30.5
5.1
6.6
2.6
2.1
0.9
6.4
-
5.7
0.4
13.5
AA-N-Co
35.0
6.0
1.4
0.2
1.6
1.0
5.7
-
5.6
2.1
27.7
AA-D-Co
38.7
3.5
1.1
0.2
0.4
0.7
5.4
-
10.6
2.5
49.9
AA-IE-Co
32.0
5.2
4.1
0.5
1.7
0.9
6.3
-
5.9
0.9
115.8
AA-IE-CoMn
31.9
5.2
4.2
0.5
1.7
0.9
5.4
0.8
5.9
0.7
118.6
* AM = alkali me als (Na + K), ** SSA = speci ic su ace a ea (BET).
These h ee ypes o suppo based on zeoli e oams (AA-S, AA-N, AA-D) and one comme cial
suppo s (γ- Al2O3) we e used o p epa e cobal ca alys s wi h 5 w .% Co con en . The ac ual cobal
con en anged om 4.8 o 6.4 w .%, as de e mined by XRF he sligh ly highe cobal con en was due
o he non-s oichiome ic wa e con en o he cobal ni a e hyd a e. The las wo ca alys s es ed (AA-
IE-Co and AA-IE-CoMn) we e p epa ed by a di ec ion-exchange me hod using a solu ion o cobal
ni a e, and mix u e o cobal ni a e wi h manganese ni a e, espec i ely. The cobal con en o
AA-IE-Co ca alys s was 6.3 w .% and he cobal con en o he AA-IE-CoMn ca alys was 5.4 w .% and
manganese 0.8 w .%, espec i ely. The cobal con en was a e age o he whole pelle , so he cobal
con en in he ac i e laye o AA-IE-Co ca alys is highe han 6.3 w .% ( heo e ically up o abou 13
w .% o abou up 11 w .% o AA-IE-CoMn ca alys ). The mola a io o Co/Mn is 6.5:1, he di e ence
compa ed o he a ge a io (Co/Mn 4:1) is due o he di e en cou se o p ecipi a ion o Co and Mn
ions du ing he o ma ion o he laye in he pelle . Ca alys s p epa ed using his me hod had a
signi ican ly highe con en o po assium and sligh ly highe con en o sodium in compa ison wi h a
ca alys imp egna ed on AA-N suppo . This showed ha cobal p ecipi a ion p ecluded comple e
ion-exchange o Na+ and K+ ions by Co2+ ion. Highe Na and K con en s we e obse ed only o he
AA-S-Co ca alys , bu he alkalis we e p esen he e in he o m o Na/K silica es. As Table 1 shows, he
p esence o hese componen s had a e y nega i e e ec on he speci ic su ace a ea (SSA) because he
silica es closed he po es. Addi ionally, due o po e opening and cleaning, he e was also an inc ease in
speci ic su ace a ea (SSA) wo imes o (AA-N) and mo e han se en imes o AA-D. SSA o ca alys s
did no change signi ican ly compa e o o iginal suppo s. The dec ease o SSA was obse ed only o
alumina and AA-D suppo ed ca alys , which could ha e been caused by pa ially blocking he po es
wi h cobal , mo e p ecisely, i s oxide. This dec ease in AA-D was ela ed o blockade o clinop iloli e
mic opo es which ha e been eleased by acid leaching [4,8]. The ca alys s AA-IE-Co and AA-IE-CoMn
p epa ed in his way exhibi ela i ely high speci ic su ace (SSA) a eas compa ed o ca alys s
employing di e en ly modi ied zeoli e oam suppo s (Table 1). This was p obably pa ially caused by
c
)
Figu e 1.
Mac opo ous s uc u e o zeoli e oam AA-S (
a
), c ys alline Na/K silica e (whi e a ow) in
AA-S (b) and lea es o Na/K silica es in AA-S-Co ca alys (c).
These h ee ypes o suppo based on zeoli e oams (AA-S, AA-N, AA-D) and one comme cial
suppo s (
γ
- Al
2
O
3
) we e used o p epa e cobal ca alys s wi h 5 w .% Co con en . The ac ual cobal
con en anged om 4.8 o 6.4 w .%, as de e mined by XRF he sligh ly highe cobal con en was due
o he non-s oichiome ic wa e con en o he cobal ni a e hyd a e. The las wo ca alys s es ed
(AA-IE-Co and AA-IE-CoMn) we e p epa ed by a di ec ion-exchange me hod using a solu ion o
cobal ni a e, and mix u e o cobal ni a e wi h manganese ni a e, espec i ely. The cobal con en
o AA-IE-Co ca alys s was 6.3 w .% and he cobal con en o he AA-IE-CoMn ca alys was 5.4 w .%
and manganese 0.8 w .%, espec i ely. The cobal con en was a e age o he whole pelle , so he
cobal con en in he ac i e laye o AA-IE-Co ca alys is highe han 6.3 w .% ( heo e ically up o
abou 13 w .% o abou up 11 w .% o AA-IE-CoMn ca alys ). The mola a io o Co/Mn is 6.5:1,
he di e ence compa ed o he a ge a io (Co/Mn 4:1) is due o he di e en cou se o p ecipi a ion o
Co and Mn ions du ing he o ma ion o he laye in he pelle . Ca alys s p epa ed using his me hod
had a signi ican ly highe con en o po assium and sligh ly highe con en o sodium in compa ison
wi h a ca alys imp egna ed on AA-N suppo . This showed ha cobal p ecipi a ion p ecluded
comple e ion-exchange o Na
+
and K
+
ions by Co
2+
ion. Highe Na and K con en s we e obse ed
only o he AA-S-Co ca alys , bu he alkalis we e p esen he e in he o m o Na/K silica es. As Table 1
shows, he p esence o hese componen s had a e y nega i e e ec on he speci ic su ace a ea (SSA)
because he silica es closed he po es. Addi ionally, due o po e opening and cleaning, he e was
also an inc ease in speci ic su ace a ea (SSA) wo imes o (AA-N) and mo e han se en imes o
AA-D. SSA o ca alys s did no change signi ican ly compa e o o iginal suppo s. The dec ease o
SSA was obse ed only o alumina and AA-D suppo ed ca alys , which could ha e been caused by
pa ially blocking he po es wi h cobal , mo e p ecisely, i s oxide. This dec ease in AA-D was ela ed o
blockade o clinop iloli e mic opo es which ha e been eleased by acid leaching [
4
,
8
]. The ca alys s
Ca alys s 2020,10, 1398 5 o 21
AA-IE-Co and AA-IE-CoMn p epa ed in his way exhibi ela i ely high speci ic su ace (SSA) a eas
compa ed o ca alys s employing di e en ly modi ied zeoli e oam suppo s (Table 1). This was
p obably pa ially caused by he o ma ion o po ous cobal and cobal -manganese oxides o igina ing
om p ecipi a ed hyd oxides on he zeoli e oam su ace, o by pa ial cleaning o he zeoli e oam
su ace (an inc ease o c ys allini y o in ensi y espec i ely was obse ed, Figu e 2) and accessibili y
o po es. The inc ease in he su ace a ea has no ye been sa is ac o ily explained bu has been e i ied
by epea ed measu emen s. Ru kowska [
53
] s a es ha he inc ease in su ace a ea o he samples
(Cu, Fe and Co be a zeoli es) could be ela ed o he seconda y ec ys alliza ion o zeoli es du ing he
p epa a ion o ca alys s. In his case, i could also be caused by changes in he binde N/K-A-S-H phase
o by he gene a ion o addi ional po osi y be ween he cobal and manganese hyd oxides deposi ed
on he sample su ace.
Ca alys s 2020, 10, x FOR PEER REVIEW 5 o 22
he o ma ion o po ous cobal and cobal -manganese oxides o igina ing om p ecipi a ed hyd oxides
on he zeoli e oam su ace, o by pa ial cleaning o he zeoli e oam su ace (an inc ease o c ys allini y
o in ensi y espec i ely was obse ed, Figu e 2) and accessibili y o po es. The inc ease in he su ace
a ea has no ye been sa is ac o ily explained bu has been e i ied by epea ed measu emen s.
Ru kowska [53] s a es ha he inc ease in su ace a ea o he samples (Cu, Fe and Co be a zeoli es) could
be ela ed o he seconda y ec ys alliza ion o zeoli es du ing he p epa a ion o ca alys s. In his case,
i could also be caused by changes in he binde N/K-A-S-H phase o by he gene a ion o addi ional
po osi y be ween he cobal and manganese hyd oxides deposi ed on he sample su ace.
Since he samples a e p edominan ly mac opo ous ma e ials, ex u es o ca aly ic suppo s and
p epa ed ca alys s we e de e mined ia Hg po osime y. The ob ained esul s (Figu e 2) showed ha
o he suppo s con ain p edominan ly bigge po es. Zeoli e oams ha e b oad po e spec um om
mesopo es o mac opo es o supe mac opo es wi h a diame e o en hs o hund eds o mic ome es
wi h co esponding po e mean size housands nm. To al in usion olume o zeoli e oams a ies om
0.65 (AA-S) o 0.75 mL/g (AA-D). In usion olume o hei “mesopo es” is om 0.06 mL/g (AA-S), 0.07
mL/g (AA-N) o 0.09 mL/g (AA-D). Inc ease in o al in usion olume and sha e o AA-D suppo
mesopo es was caused by cleansing he su ace om he excess alkali ac i a o and mine al sedimen s
inside he po es o na u al zeoli e. In he case o cobal ca alys s as well o used ca alys s (a e ca aly ic
eac ion o N2O decomposi ion), he e we e no big changes (dec eases) obse ed in in usion olume.
Changes we e only due o blocking he po es wi h cobal oxide. In con as , an inc ease o he mesopo e
olume was obse ed in AA-IE-Co and AA-IE-CoMn ca alys s (bo h 0.09 mL/g), which can be a ibu ed
o cobal oxides o med du ing he ca alys syn hesis. Alumina as compa a i e suppo is pu ely
mesopo ous ma e ial wi h he o e all in usion olume o 0.5 mL/g and mean po e diame e 5.6 nm,
Co-Al2O3 ca alys shows a pa ial educ ion in in usion olume due o cobal oxides deposi ed on he
su ace (Appendix A Figu e A1).
Figu e 2. Po e dis ibu ion o suppo s, esh and used cobal ca alys s.
SEM-EDS mapping o ca alys pelle c oss-sec ion (Figu e 3) showed iden ical mac opo ous
s uc u e o he ca alys s (e e y i s igu e in he ow) and homogeneous dis ibu ion o cobal on he
Figu e 2. Po e dis ibu ion o suppo s, esh and used cobal ca alys s.
Since he samples a e p edominan ly mac opo ous ma e ials, ex u es o ca aly ic suppo s and
p epa ed ca alys s we e de e mined ia Hg po osime y. The ob ained esul s (Figu e 2) showed ha
o he suppo s con ain p edominan ly bigge po es. Zeoli e oams ha e b oad po e spec um om
mesopo es o mac opo es o supe mac opo es wi h a diame e o en hs o hund eds o mic ome es
wi h co esponding po e mean size housands nm. To al in usion olume o zeoli e oams a ies om
0.65 (AA-S) o 0.75 mL/g (AA-D). In usion olume o hei “mesopo es” is om 0.06 mL/g (AA-S),
0.07 mL/g (AA-N) o 0.09 mL/g (AA-D). Inc ease in o al in usion olume and sha e o AA-D suppo
mesopo es was caused by cleansing he su ace om he excess alkali ac i a o and mine al sedimen s
inside he po es o na u al zeoli e. In he case o cobal ca alys s as well o used ca alys s (a e ca aly ic
eac ion o N
2
O decomposi ion), he e we e no big changes (dec eases) obse ed in in usion olume.
Changes we e only due o blocking he po es wi h cobal oxide. In con as , an inc ease o he
mesopo e olume was obse ed in AA-IE-Co and AA-IE-CoMn ca alys s (bo h 0.09 mL/g), which can
be a ibu ed o cobal oxides o med du ing he ca alys syn hesis. Alumina as compa a i e suppo is
pu ely mesopo ous ma e ial wi h he o e all in usion olume o 0.5 mL/g and mean po e diame e

Ca alys s 2020,10, 1398 6 o 21
5.6 nm, Co-Al
2
O
3
ca alys shows a pa ial educ ion in in usion olume due o cobal oxides deposi ed
on he su ace (Appendix AFigu e A1).
SEM-EDS mapping o ca alys pelle c oss-sec ion (Figu e 3) showed iden ical mac opo ous
s uc u e o he ca alys s (e e y i s igu e in he ow) and homogeneous dis ibu ion o cobal on he
su ace o he modi ied zeoli e oam ca alys suppo in he case o AA-N-Co and AA-D-Co ca alys s
(Figu e 3b,c). In case o imp egna ion o he AA-S suppo (Figu e 3a), an a ea non-co e ed by cobal
was obse able in he middle o he pelle , which could be caused by p ecipi a ion o cobal hyd oxide
du ing imp egna ion p ocess by alkali agen s in he zeoli e oam. This as-c ea ed laye was blocking
u he imp egna ion inside he pelle . Ce ainly, his will also be a ec ed by he inhomogenei y o
he pelle s caused by he syn hesis me hod used. A simila e ec was obse ed du ing p epa a ions
ia he di ec ion-exchange me hod. As can be seen in Figu e 3d,e cobal was obse ed only on he
ou e su ace o he pelle in he o m o a ing. The dep h o cobal pene a ion eached app oxima ely
0.7 mm. The di e ence in dep h compa ed o AA-S-Co was due o di e en ca alys p epa a ion
condi ions (solu ion concen a ion, empe a u e, e c.). Manganese dis ibu ion showed a decline in
con en om he su ace o he co e, bu in compa ison wi h cobal , he e was no a s ong bo de line.
The e was a signi ican decline in con en o sodium and po assium (obse able om g ey and yellow
colou in ensi y on Figu e 3) in he ollowing o de : AA-S-Co, AA-IE-Co/AA-IE-CoMn, AA-N-Co
and AA-D-Co and dis ibu ion in he whole c oss-sec ion is in ag eemen wi h esul s o chemical
analysis (XRF).
Ca alys s 2020, 10, x FOR PEER REVIEW 6 o 22
su ace o he modi ied zeoli e oam ca alys suppo in he case o AA-N-Co and AA-D-Co ca alys s
(Figu e 3b,c). In case o imp egna ion o he AA-S suppo (Figu e 3a), an a ea non-co e ed by cobal
was obse able in he middle o he pelle , which could be caused by p ecipi a ion o cobal hyd oxide
du ing imp egna ion p ocess by alkali agen s in he zeoli e oam. This as-c ea ed laye was blocking
u he imp egna ion inside he pelle . Ce ainly, his will also be a ec ed by he inhomogenei y o he
pelle s caused by he syn hesis me hod used. A simila e ec was obse ed du ing p epa a ions ia he
di ec ion-exchange me hod. As can be seen in Figu e 3d,e cobal was obse ed only on he ou e su ace
o he pelle in he o m o a ing. The dep h o cobal pene a ion eached app oxima ely 0.7 mm. The
di e ence in dep h compa ed o AA-S-Co was due o di e en ca alys p epa a ion condi ions (solu ion
concen a ion, empe a u e, e c.). Manganese dis ibu ion showed a decline in con en om he su ace
o he co e, bu in compa ison wi h cobal , he e was no a s ong bo de line. The e was a signi ican
decline in con en o sodium and po assium (obse able om g ey and yellow colou in ensi y on Figu e
3) in he ollowing o de : AA-S-Co, AA-IE-Co/AA-IE-CoMn, AA-N-Co and AA-D-Co and dis ibu ion
in he whole c oss-sec ion is in ag eemen wi h esul s o chemical analysis (XRF).
Figu e 3. SEM-EDS elemen al mapping o sodium (g ay), po assium (yellow), cobal (g een) and
manganese (b own) on c oss sec ion a ea o AA-S-Co (a), AA-N-Co (b), AA-D-Co (c), AA-IE-Co (d) and
AA-IE-CoMn (e) ca alys s.
The c ys alline s uc u e o ma e ials was de e mined using X- ay powde di ac ion (XRD). In
case o zeoli e oam suppo ed ca alys s, he analysis showed clinop iloli e o be a main c ys alline phase
Figu e 3.
SEM-EDS elemen al mapping o sodium (g ay), po assium (yellow), cobal (g een) and
manganese (b own) on c oss sec ion a ea o AA-S-Co (
a
), AA-N-Co (
b
), AA-D-Co (
c
), AA-IE-Co (
d
)
and AA-IE-CoMn (e) ca alys s.
Ca alys s 2020,10, 1398 7 o 21
The c ys alline s uc u e o ma e ials was de e mined using X- ay powde di ac ion (XRD).
In case o zeoli e oam suppo ed ca alys s, he analysis showed clinop iloli e o be a main c ys alline
phase wi h ypical e lec ions a 2 he a 9.9
◦
, 11.2
◦
, 17.5
◦
and 22.4
◦
(PDF 83-1261) along wi h o he mino
phases in he na u al zeoli e, belonging o he mine alogic g oup o clays and eldspa s (Figu e 4a).
Thedi ac og amsshowed hedi e ence in c ys allini y o in ensi ies o main e lec ionso clinop iloli e
espec i ely depending on he modi ica ion me hod used. The c ys allini y o alkali-ac i a ed ma e ial
was lowe in compa ison wi h he o iginal na u al zeoli e [
8
]. This may be caused by a pa ial s uc u e
dis up ion du ing he alkaline ac i a ion. The e was a signi ican inc ease in c ys allini y a e IE
using NH
4
NO
3
caused by su ace cleansing. In con as , a e leaching wi h 3M HCl, he e was a
dec ease in c ys allini y connec ed wi h dis up ion o he zeoli e s uc u e due o emo ing Al om he
clinop iloli e c ys alline ma ix. Du ing he modi ica ion p ocess, he e was a change in in ensi ies a
2 he a 11.2
◦
/9.9
◦
ha co esponded o planes (020) and (200), caused by he di e ence in elec on densi y
in ha plane. F om he o iginal a io 0.5 in he na u al zeoli e, he alue inc eases a e alkali-ac i a ion
o 0.8 and a e leaching wi h HCl o IE ea men , i dec eases o 0.4 [
8
]. Compa a i e ca alys s showed
ypical b oad e lec ions o γ-Al2O3(2 he a 46.5◦and 67.3◦, PDF 74-2206) (Appendix AFigu e A2).
Ca alys s 2020, 10, x FOR PEER REVIEW 7 o 22
wi h ypical e lec ions a 2 he a 9.9°, 11.2°, 17.5° and 22.4° (PDF 83-1261) along wi h o he mino phases
in he na u al zeoli e, belonging o he mine alogic g oup o clays and eldspa s (Figu e 4a). The
di ac og ams showed he di e ence in c ys allini y o in ensi ies o main e lec ions o clinop iloli e
espec i ely depending on he modi ica ion me hod used. The c ys allini y o alkali-ac i a ed ma e ial
was lowe in compa ison wi h he o iginal na u al zeoli e [8]. This may be caused by a pa ial s uc u e
dis up ion du ing he alkaline ac i a ion. The e was a signi ican inc ease in c ys allini y a e IE using
NH4NO3 caused by su ace cleansing. In con as , a e leaching wi h 3M HCl, he e was a dec ease in
c ys allini y connec ed wi h dis up ion o he zeoli e s uc u e due o emo ing Al om he clinop iloli e
c ys alline ma ix. Du ing he modi ica ion p ocess, he e was a change in in ensi ies a 2 he a 11.2°/9.9°
ha co esponded o planes (020) and (200), caused by he di e ence in elec on densi y in ha plane.
F om he o iginal a io 0.5 in he na u al zeoli e, he alue inc eases a e alkali-ac i a ion o 0.8 and
a e leaching wi h HCl o IE ea men , i dec eases o 0.4 [8]. Compa a i e ca alys s showed ypical
b oad e lec ions o γ-Al2O3 (2 he a 46.5° and 67.3°, PDF 74-2206) (Appendix A Figu e A2).
Figu e 4. Powde di ac ion pa e ns o suppo s (a) and esh ca alys s (b).
Cobal ca alys s p epa ed using hese suppo s showed signi ican c ys alline s uc u es
co esponding o Co3O4 (2 he a 31.5°, 36.9°, 45.0°, 55.7°, 59.6° and 65.6°, PDF 65-3103). These we e he
mos appa en in case o using alumina as suppo (Appendix A Figu e A2). In case o o he suppo s
(Figu e 4b), he e was only one e lec ion isible (36.9° 2 he a), while AA-D suppo ed ca alys s showed
he e lec ions co esponding o clinop iloli e (2 he a 9.9° and 11.2°) and o he mino phases (clays and
eldspa s) wi h no signi ican in ensi ies co esponding o cobal oxide. This indica ed homogeneous
dis ibu ion o cobal on he su ace wi hou he o ma ion o a c ys alline Co3O4 phase. C ys alli e size
o Co3O4 calcula ed using he Sche e equa ion om he e lec ion 36.9° 2 he a is 12 nm o ca alys s
wi h alumina suppo . I was no possible o e alua e he c ys alli e size in o he ca alys s due o o e lap
o cobal oxide di ac ion wi h line assigned o he clinop iloli e, qua z o ano hi e.
Analysis o he used ca alys s (Appendix A Figu e A3), samples labelled wi h addi ional –U,
ca alys s a e hei usage o N2O decomposi ion es ) did no show any signi ican changes in he
c ys alline s uc u e compa ed wi h esh ca alys s. Powde di ac ion pa e ns o Al2O3 can be seen in
Appendix A Figu e A2. A e using he ca alys s in he eac ion es only sligh dec eases in in ensi y
a e no iceable. Only in he case o he AA-D-Co-U ca alys , he e was a signi ican dec ease in in ensi ies
2 he a 27.8°, 28.0° and o he s co esponding o ano hi e (PDF 71-0748).
Tempe a u e-p og ammed ammonia deso p ion (NH3-TPD) showed signi ican di e ences in he
amoun and s eng h o acid si es (Figu e 5a) o each ca alys (Table 2). While he ca alys suppo ed on
indus ial suppo (Al2O3-Co) showed low acidi y (Appendix A Table A2, Figu e A4a), he zeoli e oam
suppo ed ca alys s showed changes in acidi y depending on he suppo modi ica ion me hod du ing
ca alys p epa a ion. In gene al, peaks a low empe a u es, below 200 °C a e a ibu ed o weakly acidic
si es o physiso bed ammonia, and peaks a highe empe a u es in he ange o 200–400 °C a e
associa ed wi h he in e ac ion o NH3 wi h acidic B øns ed si es a ibu ed o s ongly acidic si es. Peaks
Figu e 4. Powde di ac ion pa e ns o suppo s (a) and esh ca alys s (b).
Cobal ca alys s p epa ed using hese suppo s showed signi ican c ys alline s uc u es
co esponding o Co
3
O
4
(2 he a 31.5
◦
, 36.9
◦
, 45.0
◦
, 55.7
◦
, 59.6
◦
and 65.6
◦
, PDF 65-3103). These we e he
mos appa en in case o using alumina as suppo (Appendix AFigu e A2). In case o o he suppo s
(Figu e 4b), he e was only one e lec ion isible (36.9
◦
2 he a), while AA-D suppo ed ca alys s showed
he e lec ions co esponding o clinop iloli e (2 he a 9.9
◦
and 11.2
◦
) and o he mino phases (clays and
eldspa s) wi h no signi ican in ensi ies co esponding o cobal oxide. This indica ed homogeneous
dis ibu ion o cobal on he su ace wi hou he o ma ion o a c ys alline Co
3
O
4
phase. C ys alli e size
o Co
3
O
4
calcula ed using he Sche e equa ion om he e lec ion 36.9
◦
2 he a is 12 nm o ca alys s
wi h alumina suppo . I was no possible o e alua e he c ys alli e size in o he ca alys s due o
o e lap o cobal oxide di ac ion wi h line assigned o he clinop iloli e, qua z o ano hi e.
Analysis o he used ca alys s (Appendix AFigu e A3), samples labelled wi h addi ional –U,
ca alys s a e hei usage o N
2
O decomposi ion es ) did no show any signi ican changes in he
c ys alline s uc u e compa ed wi h esh ca alys s. Powde di ac ion pa e ns o Al
2
O
3
can be seen in
Appendix AFigu e A2. A e using he ca alys s in he eac ion es only sligh dec eases in in ensi y a e
no iceable. Only in he case o he AA-D-Co-U ca alys , he e was a signi ican dec ease in in ensi ies
2 he a 27.8◦, 28.0◦and o he s co esponding o ano hi e (PDF 71-0748).
Tempe a u e-p og ammed ammonia deso p ion (NH
3
-TPD) showed signi ican di e ences in he
amoun and s eng h o acid si es (Figu e 5a) o each ca alys (Table 2). While he ca alys suppo ed on
indus ial suppo (Al
2
O
3
-Co) showed low acidi y (Appendix ATable A2, Figu e A4a), he zeoli e oam
suppo ed ca alys s showed changes in acidi y depending on he suppo modi ica ion me hod du ing
ca alys p epa a ion. In gene al, peaks a low empe a u es, below 200
◦
C a e a ibu ed o weakly
Ca alys s 2020,10, 1398 8 o 21
acidic si es o physiso bed ammonia, and peaks a highe empe a u es in he ange o 200–400
◦
C a e
associa ed wi h he in e ac ion o NH
3
wi h acidic B øns ed si es a ibu ed o s ongly acidic si es.
Peaks a empe a u es abo e 400
◦
C co espond o he in e ac ion o NH
3
wi h Lewis acids and a e
a ibu ed o Co-O species ha o m e y s ongly acidic si es [54–56]
Ca alys s 2020, 10, x FOR PEER REVIEW 8 o 22
a empe a u es abo e 400 °C co espond o he in e ac ion o NH3 wi h Lewis acids and a e a ibu ed
o Co-O species ha o m e y s ongly acidic si es [54–56]
The highes o al acidi y exhibi ed ca alys p epa ed ia imp egna ion o ion-exchange modi ied
suppo (AA-N-Co), which con ained a high popula ion o s ong acid si es, i.e., si es wi h high NH3
deso p ion empe a u e. The acidi y o AA-S-Co and AA-D-Co ca alys s is abou one- hi d in
compa ison and e y simila o each o he , which is p obably due o poo a ailabili y o acid si es in he
base zeoli e–clinop iloli e o AA-S-Co and in case o AA-D-Co due o acid cen e emo al du ing acid
leaching. Samples p epa ed using di ec ion-exchange ea men showed sligh ly lowe acidi y han
AA-N-Co, bu no s ong acid si es.
Table 2. Acidi y o cobal ca alys s de e mined by ammonia TPD.
Sample
cSUM
(μmol/g)
Tmax1
(°C)
cmax1
(μmol/g)
Pmax1 *
(%)
Tmax2
(°C)
cmax2
(μmol/g)
Pmax2 *
(%)
Tmax3
(°C)
cmax3
(μmol/g)
Pmax3 *
(%)
AA-S-Co
501
175
501
100
-
-
-
-
-
-
AA-N-Co
1542
173
1313
85
390
229
15
-
-
-
AA-D-Co
593
158
446
75
255
70
12
382
77
13
AA-IE-Co
1446
178
1379
95
247
27
2
362
40
3
AA-IE-MnCo
1211
187
1211
100
-
-
-
-
-
-
* P = popula ion o he ele an si es, index 1– i s decon olu ion peak, 2–second decon olu ion peak
and 3– hi d decon olu ion peak.
Figu e 5. Acidi y (a) and basici y (b) o cobal ca alys s de e mined by NH3-TPD and CO2-TPD,
espec i ely.
The basici y o he ca alys s was de e mined by empe a u e p og ammed deso p ion o CO2 (CO2-
TPD). The da a ob ained (Table 3, Figu e 5b) showed signi ican low empe a u e peaks a ound 110 °C
o ion-exchange ea ed (AA-N-Co) ca alys , di ec ion-exchange ea ed (AA-IE-Co and AA-IE-CoMn)
ca alys s and a simila maximum is also obse ed o he Al2O3-Co ca alys (Appendix A Table A3,
Figu e A4b). The basici y is ela ed o he alkali con en , i.e., alkali me als (Na + K) in he sample (Table
3). The AA-S-Co ca alys had he highes alkali con en , bu a la ge pa o he alkali me als was
inaccessible o he in e ac ion ( hey we e enclosed in he binde N(A)-A-S-H phase), while in he case
o AA-IE-Co and AA-IE-CoMn ca alys s which had also highe SSA, alkali me als we e mo e a ailable
and he samples showed high o e all basici y, especially also he con en o weakly basic si es. On he
o he hand, he basici y o he samples may also be ela ed o he adso p ion o CO2 on he pola
adso p ion cen es, i.e., on all coo dina ion unsa u a ed ca ions p esen in he sample.
Figu e 5.
Acidi y (
a
) and basici y (
b
) o cobal ca alys s de e mined by NH
3
-TPD and
CO2-TPD, espec i ely.
Table 2. Acidi y o cobal ca alys s de e mined by ammonia TPD.
Sample cSUM
(µmol/g)
Tmax1
(◦C)
cmax1
(µmol/g)
Pmax1 *
(%)
Tmax2
(◦C)
cmax2
(µmol/g)
Pmax2 *
(%)
Tmax3
(◦C)
cmax3
(µmol/g)
Pmax3 *
(%)
AA-S-Co 501 175 501 100 - - - - - -
AA-N-Co 1542 173 1313 85 390 229 15 - - -
AA-D-Co 593 158 446 75 255 70 12 382 77 13
AA-IE-Co 1446 178 1379 95 247 27 2 362 40 3
AA-IE-MnCo 1211 187 1211 100 - - - - - -
* P =popula ion o he ele an si es, index 1– i s decon olu ion peak, 2–second decon olu ion peak and 3– hi d
decon olu ion peak.
The highes o al acidi y exhibi ed ca alys p epa ed ia imp egna ion o ion-exchange modi ied
suppo (AA-N-Co), which con ained a high popula ion o s ong acid si es, i.e., si es wi h high
NH
3
deso p ion empe a u e. The acidi y o AA-S-Co and AA-D-Co ca alys s is abou one- hi d in
compa ison and e y simila o each o he , which is p obably due o poo a ailabili y o acid si es in
he base zeoli e–clinop iloli e o AA-S-Co and in case o AA-D-Co due o acid cen e emo al du ing
acid leaching. Samples p epa ed using di ec ion-exchange ea men showed sligh ly lowe acidi y
han AA-N-Co, bu no s ong acid si es.
The basici y o he ca alys s was de e mined by empe a u e p og ammed deso p ion o CO
2
(CO
2
-TPD). The da a ob ained (Table 3, Figu e 5b) showed signi ican low empe a u e peaks a ound
110
◦
C o ion-exchange ea ed (AA-N-Co) ca alys , di ec ion-exchange ea ed (AA-IE-Co and
AA-IE-CoMn) ca alys s and a simila maximum is also obse ed o he Al
2
O
3
-Co ca alys (Appendix A
Table A3, Figu e A4b). The basici y is ela ed o he alkali con en , i.e., alkali me als (Na +K) in he
sample (Table 3). The AA-S-Co ca alys had he highes alkali con en , bu a la ge pa o he alkali
me als was inaccessible o he in e ac ion ( hey we e enclosed in he binde N(A)-A-S-H phase), while
in he case o AA-IE-Co and AA-IE-CoMn ca alys s which had also highe SSA, alkali me als we e
mo e a ailable and he samples showed high o e all basici y, especially also he con en o weakly
basic si es. On he o he hand, he basici y o he samples may also be ela ed o he adso p ion o CO
2
on he pola adso p ion cen es, i.e., on all coo dina ion unsa u a ed ca ions p esen in he sample.
Ca alys s 2020,10, 1398 9 o 21
Table 3. Basici y o cobal ca alys s de e mined by CO2-TPD.
Sample cSUM
(µmol/g)
Tmax1
(◦C)
cmax1
(µmol/g)
Pmax1 *
(%)
Tmax2
(◦C)
cmax2
(µmol/g)
Pmax2 *
(%)
Tmax3
(◦C)
cmax3
(µmol/g)
Pmax3 *
(%)
AA-S-Co 213 105 42 20 186 161 76 321 10 14
AA-N-Co 125 110 82 66 363 14 11 437 30 23
AA-D-Co 156 112 36 23 204 44 28 289 76 49
AA-IE-Co 306 111 215 70 338 91 30 - - -
AA-IE-MnCo 408 113 227 56 273 181 44 - - -
* P =popula ion o he ele an si es, index 1– i s decon olu ion peak, 2–second decon olu ion peak and 3– hi d
decon olu ion peak.
The esul s o he H
2
-TPR analysis pe o med on he ca alys pelle s show signi ican di e ences in
H
2
consump ion (Table 4), which co esponds o he con en o a ious o ms o Co oxides p esen on
he su ace o he ca alys suppo . Co
3
O
4
educ ion akes place in wo s eps, mos o en pa ame e s o
educ ion o Co
3+
o Co
2+
a e he empe a u e ange o 250–300
◦
C and highe han 400
◦
C o educ ion
o Co
2+
o Co
0
[
9
,
10
]. F om he ob ained TPR p o iles (Figu e 6) i can be seen ha he educ ion ook
place in he wo s eps, bu signi ican di e ences a e obse ed o he indi idual ca alys s. The esul s
o he H2-TPR analysis pe o med on he Al2O3 can be seen in Appendix ATable A4 and Figu e A5.
Table 4. Reducibili y o cobal ca alys s de e mined by TPR.
Sample cSUM
(µmol/g)
Tmax1
(◦C)
cmax1
(µmol/g)
Pmax1 *
(%)
Tmax2
(◦C)
cmax2
(µmol/g)
Pmax2 *
(%)
Tmax3
(◦C)
cmax3
(µmol/g)
Pmax3 *
(%)
AA-S-Co 360 289 77 21 330 218 61 478 65 19
AA-N-Co 875 304 704 80 483 171 20 - - -
AA-D-Co 260 284 76 29 306 184 71 - -
AA-IE-Co 176 222 60 34 418 116 66 - - -
AA-IE-MnCo 500 239 337 67 303 163 33 - - -
* P =popula ion o he ele an si es, index 1– i s decon olu ion peak, 2–second decon olu ion peak and 3– hi d
decon olu ion peak.
Ca alys s 2020, 10, x FOR PEER REVIEW 9 o 22
Table 3. Basici y o cobal ca alys s de e mined by CO2-TPD.
Sample
cSUM
(μmol/g)
Tmax1
(°C)
cmax1
(μmol/g)
Pmax1 *
(%)
Tmax2
(°C)
cmax2
(μmol/g)
Pmax2 *
(%)
Tmax3
(°C)
cmax3
(μmol/g)
Pmax3 *
(%)
AA-S-Co
213
105
42
20
186
161
76
321
10
14
AA-N-Co
125
110
82
66
363
14
11
437
30
23
AA-D-Co
156
112
36
23
204
44
28
289
76
49
AA-IE-Co
306
111
215
70
338
91
30
-
-
-
AA-IE-MnCo
408
113
227
56
273
181
44
-
-
-
* P = popula ion o he ele an si es, index 1– i s decon olu ion peak, 2–second decon olu ion peak
and 3– hi d decon olu ion peak.
The esul s o he H2-TPR analysis pe o med on he ca alys pelle s show signi ican di e ences in
H2 consump ion (Table 4), which co esponds o he con en o a ious o ms o Co oxides p esen on
he su ace o he ca alys suppo . Co3O4 educ ion akes place in wo s eps, mos o en pa ame e s o
educ ion o Co3+ o Co2+ a e he empe a u e ange o 250–300 °C and highe han 400 °C o educ ion
o Co2+ o Co0 [9,10]. F om he ob ained TPR p o iles (Figu e 6) i can be seen ha he educ ion ook
place in he wo s eps, bu signi ican di e ences a e obse ed o he indi idual ca alys s. The esul s
o he H2-TPR analysis pe o med on he Al2O3 can be seen in Appendix A Table A4 and Figu e A5.
Table 4. Reducibili y o cobal ca alys s de e mined by TPR.
Sample
cSUM
(μmol/g)
Tmax1
(°C)
cmax1
(μmol/g)
Pmax1 *
(%)
Tmax2
(°C)
cmax2
(μmol/g)
Pmax2 *
(%)
Tmax3
(°C)
cmax3
(μmol/g)
Pmax3 *
(%)
AA-S-Co
360
289
77
21
330
218
61
478
65
19
AA-N-Co
875
304
704
80
483
171
20
-
-
-
AA-D-Co
260
284
76
29
306
184
71
-
-
AA-IE-Co
176
222
60
34
418
116
66
-
-
-
AA-IE-MnCo
500
239
337
67
303
163
33
-
-
-
* P = popula ion o he ele an si es, index 1– i s decon olu ion peak, 2–second decon olu ion peak
and 3– hi d decon olu ion peak.
Figu e 6. H2-TPR p o iles o cobal ca alys s.
The shi o he educ ion peaks may occu due o (i) he p esence o alkali [35] which gene ally
lowe s empe a u es o educ ion o cobal species, o (ii) due o he in e ac ion be ween he Co3O4 spin
Figu e 6. H2-TPR p o iles o cobal ca alys s.
The shi o he educ ion peaks may occu due o (i) he p esence o alkali [
35
] which gene ally
lowe s empe a u es o educ ion o cobal species, o (ii) due o he in e ac ion be ween he Co
3
O
4
spin
phase and he suppo used [
51
]. In case o he alumina suppo ed ca alys , only one wide educ ion
peak was e iden wi h wo maxima a 435
◦
C and 479
◦
C, indica ing cobal species in e ac ion wi h
Al
2
O
3
o o m Co alumina es wi h s onge oxygen bonds ha dec ease educibili y (Appendix A
Table A4, Figu e A5) [
11
]. The ca alys using he AA-S basic suppo exhibi ed a wide educ ion peak
Ca alys s 2020,10, 1398 16 o 21
Table A2. Acidi y o cobal ca alys de e mined by ammonia TPD.
Sample cSUM
(µmol/g)
Tmax1
(◦C)
cmax1
(µmol/g)
Pmax1
* (%)
Tmax2
(◦C)
cmax2
(µmol/g)
Pmax2
* (%)
Tmax3
(◦C)
cmax3
(µmol/g)
Pmax3 *
(%)
Al2O3-Co 296 173 178 60 283 118 40 - - -
* P =popula ion o he ele an si es, index 1– i s decon olu ion peak, 2–second decon olu ion peak and 3– hi d
decon olu ion peak.
Table A3. Basici y o cobal ca alys de e mined by CO2TPD.
Sample cSUM
(µmol/g)
Tmax1
(◦C)
cmax1
(µmol/g)
Pmax1
* (%)
Tmax2
(◦C)
cmax2
(µmol/g)
Pmax2
* (%)
Tmax3
(◦C)
cmax3
(µmol/g)
Pmax3 *
(%)
Al2O3-Co 145 109 31 21 144 89 61 263 25 18
* P =popula ion o he ele an si es, index 1– i s decon olu ion peak, 2–second decon olu ion peak and 3– hi d
decon olu ion peak.
Table A4. Reducibili y o cobal ca alys de e mined by TPR.
Sample cSUM
(µmol/g)
Tmax1
(◦C)
cmax1
(µmol/g)
Pmax1
* (%)
Tmax2
(◦C)
cmax2
(µmol/g)
Pmax2
* (%)
Tmax3
(◦C)
cmax3
(µmol/g)
Pmax3 *
(%)
Al2O3-Co 109 - - - 435 85 80 479 24 20
* P =popula ion o he ele an si es, index 1– i s decon olu ion peak, 2–second decon olu ion peak and 3– hi d
decon olu ion peak.
Ca alys s 2020, 10, x FOR PEER REVIEW 16 o 22
Table A2. Acidi y o cobal ca alys de e mined by ammonia TPD.
Sample
cSUM
(μmol/g)
Tmax1
(°C)
cmax1
(μmol/g)
Pmax1 *
(%)
Tmax2
(°C)
cmax2
(μmol/g)
Pmax2 *
(%)
Tmax3
(°C)
cmax3
(μmol/g)
Pmax3 *
(%)
Al2O3-Co
296
173
178
60
283
118
40
-
-
-
* P = popula ion o he ele an si es, index 1– i s decon olu ion peak, 2–second decon olu ion peak
and 3– hi d decon olu ion peak.
Table A3. Basici y o cobal ca alys de e mined by CO2 TPD.
Sample
cSUM
(μmol/g)
Tmax1
(°C)
cmax1
(μmol/g)
Pmax1 *
(%)
Tmax2
(°C)
cmax2
(μmol/g)
Pmax2 *
(%)
Tmax3
(°C)
cmax3
(μmol/g)
Pmax3 *
(%)
Al2O3-Co
145
109
31
21
144
89
61
263
25
18
* P = popula ion o he ele an si es, index 1– i s decon olu ion peak, 2–second decon olu ion peak
and 3– hi d decon olu ion peak.
Table A4. Reducibili y o cobal ca alys de e mined by TPR.
Sample
cSUM
(μmol/g)
Tmax1
(°C)
cmax1
(μmol/g)
Pmax1 *
(%)
Tmax2
(°C)
cmax2
(μmol/g)
Pmax2 *
(%)
Tmax3
(°C)
cmax3
(μmol/g)
Pmax3 *
(%)
Al2O3-Co
109
-
-
-
435
85
80
479
24
20
* P = popula ion o he ele an si es, index 1– i s decon olu ion peak, 2–second decon olu ion peak
and 3– hi d decon olu ion peak.
Figu e A1. Po e dis ibu ion o Al2O3 suppo , esh and used cobal ca alys .
Figu e A1. Po e dis ibu ion o Al2O3suppo , esh and used cobal ca alys .

Ca alys s 2020,10, 1398 17 o 21
Ca alys s 2020, 10, x FOR PEER REVIEW 17 o 22
Figu e A2. Powde di ac ion pa e ns o Al2O3 suppo , esh and used cobal ca alys .
Figu e A3. Powde di ac ion pa e ns o used cobal ca alys s.
Figu e A2. Powde di ac ion pa e ns o Al2O3suppo , esh and used cobal ca alys .
Ca alys s 2020, 10, x FOR PEER REVIEW 17 o 22
Figu e A2. Powde di ac ion pa e ns o Al2O3 suppo , esh and used cobal ca alys .
Figu e A3. Powde di ac ion pa e ns o used cobal ca alys s.
Figu e A3. Powde di ac ion pa e ns o used cobal ca alys s.
Ca alys s 2020, 10, x FOR PEER REVIEW 18 o 22
Figu e A4. Acidi y (a) and basici y (b) o Al2O3 cobal ca alys de e mined by NH3-TPD and CO2-TPD,
espec i ely.
Figu e A5. H2-TPR p o iles o Al2O3 cobal ca alys .
Figu e A4.
Acidi y (
a
) and basici y (
b
) o Al
2
O
3
cobal ca alys de e mined by NH
3
-TPD and
CO2-TPD, espec i ely.
Ca alys s 2020,10, 1398 18 o 21
Ca alys s 2020, 10, x FOR PEER REVIEW 18 o 22
Figu e A4. Acidi y (a) and basici y (b) o Al2O3 cobal ca alys de e mined by NH3-TPD and CO2-TPD,
espec i ely.
Figu e A5. H2-TPR p o iles o Al2O3 cobal ca alys .
Figu e A5. H2-TPR p o iles o Al2O3cobal ca alys .
Ca alys s 2020, 10, x FOR PEER REVIEW 19 o 22
Figu e A6. N2O con e sion o Al2O3 cobal ca alys .
Re e ences
1. Choya, A.; De Ri as, B.; Gu ié ez-O iz, J.I.; Velasco, J.R.G.; López-Fonseca, R. Syn hesis, Cha ac e iza ion
and Kine ic Beha io o Suppo ed Cobal Ca alys s o Oxida i e a e -T ea men o Me hane Lean Mix u es.
Ma e ials 2019, 12, 3174, doi:10.3390/ma12193174.
2. Lin, H.-K.; Wang, C.-B.; Chiu, H.-C.; Chien, S.-H. In si u FTIR S udy o Cobal Oxides o he Oxida ion o
Ca bon Monoxide. Ca al. Le . 2003, 86, 63–68, doi:10.1023/a:1022659025068.
3. Zhang, J.; Li, Y.; Wang, L.; Zhang, C.; He, H. Ca aly ic oxida ion o o maldehyde o e manganese oxides wi h
di e en c ys al s uc u es. Ca al. Sci. Technol. 2015, 5, 2305–2313, doi:10.1039/c4cy01461h.
4. H acho co á, K.; Tišle , Z.; S obodo á, E.; Ša ář, J. Modi ied Alkali Ac i a ed Zeoli e Foams wi h Imp o ed
Tex u al and Mechanical P ope ies. Mine als 2020, 10, 483.
5. A kins, P.W.; Jones, L.L. Chemis y: Molecules, Ma e , and Change, 3 d ed.; W. H. F eeman and Company: New
Yo k, NY, USA, 1997.
6. Hidalgo-He ado , J.M.; Tišle , Z.; V áblík, A.; Vel a ská, R.; Lede e , J. Acid-modi ied phonoli e and oamed
zeoli e as suppo s o NiW ca alys s o deoxygena ion o was e ende ing a . Reac . Kine . Mech. Ca al. 2019,
126, 773–793, doi:10.1007/s11144-018-1510-1.
7. Tišle , Z.; Vel a ská, R.; Skuh o co á, L.; Pelíško á, L.; Akhme zyano a, U. Key Role o P ecu so Na u e in
Phase Composi ion o Suppo ed Molybdenum Ca bides and Ni ides. Ma e ials 2019, 12, 415,
doi:10.3390/ma12030415.
8. Tišle , Z.; Ho acek, J.; Sa a , J.; Vel a ska, R.; Pelisko a, L.; Kocik, J.; Ghe ib, Y.; Ma klo a, K.; Bulánek, R.;
Kubička, D. Clinop iloli e oams p epa ed by alkali ac i a ion o na u al zeoli e and hei pos -syn hesis
modi ica ions. Mic opo ous Mesopo ous Ma e . 2019, 282, 169–178, doi:10.1016/j.mic omeso.2019.03.029.
9. Maniak, G.; S elmachowski, P.; Ko a ba, A.; Sojka, Z.; Pé ez, V.R.; López, A.B. Ra ionales o he selec ion o
he bes p ecu so o po assium doping o cobal spinel based deN2O ca alys . Appl. Ca al. B En i on. 2013,
136, 302–307, doi:10.1016/j.apca b.2013.01.068.
10. Sun, M.; Wang, L.; Feng, B.; Zhang, Z.; Lu, G.; Guo, Y. The ole o po assium in K/Co3O4 o soo combus ion
unde loose con ac . Ca al. Today 2011, 175, 100–105, doi:10.1016/j.ca od.2011.04.044.
11. Obalo á, L.; Pacul o á, K.; Balabáno á, J.; Ji á o á, K.; Bas l, Z.; Valáško á, M.; Lacný, Z.; Ko anda, F. E ec
o Mn/Al a io in Co–Mn–Al mixed oxide ca alys s p epa ed om hyd o alci e-like p ecu so s on ca aly ic
decomposi ion o N2O. Ca al. Today 2007, 119, 233–238, doi:10.1016/j.ca od.2006.08.027.
12. Ramı ez, J.P.; Kap eijn, F.; Schö el, K.; Moulijn, J.A. Fo ma ion and con ol o N2O in ni ic acid p oduc ion:
Whe e do we s and oday? Appl. Ca al. B En i on. 2003, 44, 117–151.
Figu e A6. N2O con e sion o Al2O3cobal ca alys .
Re e ences
1.
Choya, A.; De Ri as, B.; Gu i
é
ez-O iz, J.I.; Velasco, J.R.G.; L
ó
pez-Fonseca, R. Syn hesis, Cha ac e iza ion
and Kine ic Beha io o Suppo ed Cobal Ca alys s o Oxida i e a e -T ea men o Me hane Lean Mix u es.
Ma e ials 2019,12, 3174. [C ossRe ] [PubMed]
2.
Lin, H.-K.; Wang, C.-B.; Chiu, H.-C.; Chien, S.-H. In si u FTIR S udy o Cobal Oxides o he Oxida ion o
Ca bon Monoxide. Ca al. Le . 2003,86, 63–68. [C ossRe ]
3.
Zhang, J.; Li, Y.; Wang, L.; Zhang, C.; He, H. Ca aly ic oxida ion o o maldehyde o e manganese oxides
wi h di e en c ys al s uc u es. Ca al. Sci. Technol. 2015,5, 2305–2313. [C ossRe ]
4.
H acho co
á
, K.; Tišle , Z.; S obodo
á
, E.; Ša
á
ˇ , J. Modi ied Alkali Ac i a ed Zeoli e Foams wi h Imp o ed
Tex u al and Mechanical P ope ies. Mine als 2020,10, 483. [C ossRe ]
5.
A kins, P.W.; Jones, L.L. Chemis y: Molecules, Ma e , and Change, 3 d ed.; W. H. F eeman and Company:
New Yo k, NY, USA, 1997.
Ca alys s 2020,10, 1398 19 o 21
6.
Hidalgo-He ado , J.M.; Tišle , Z.; V
á
bl
í
k, A.; Vel a sk
á
, R.; Lede e , J. Acid-modi ied phonoli e and oamed
zeoli e as suppo s o NiW ca alys s o deoxygena ion o was e ende ing a . Reac . Kine . Mech. Ca al.
2019,126, 773–793. [C ossRe ]
7.
Tišle , Z.; Vel a sk
á
, R.; Skuh o co
á
, L.; Pel
í
ško
á
, L.; Akhme zyano a, U. Key Role o P ecu so Na u e in
Phase Composi ion o Suppo ed Molybdenum Ca bides and Ni ides. Ma e ials
2019
,12, 415. [C ossRe ]
[PubMed]
8.
Tišle , Z.; Ho acek, J.; Sa a , J.; Vel a ska, R.; Pelisko a, L.; Kocik, J.; Ghe ib, Y.; Ma klo a, K.; Bul
á
nek, R.;
Kubiˇcka, D. Clinop iloli e oams p epa ed by alkali ac i a ion o na u al zeoli e and hei pos -syn hesis
modi ica ions. Mic opo ous Mesopo ous Ma e . 2019,282, 169–178. [C ossRe ]
9.
Maniak, G.; S elmachowski, P.; Ko a ba, A.; Sojka, Z.; P
é
ez, V.R.; L
ó
pez, A.B. Ra ionales o he selec ion o
he bes p ecu so o po assium doping o cobal spinel based deN2O ca alys . Appl. Ca al. B En i on.
2013
,
136, 302–307. [C ossRe ]
10.
Sun, M.; Wang, L.; Feng, B.; Zhang, Z.; Lu, G.; Guo, Y. The ole o po assium in K/Co3O4 o soo combus ion
unde loose con ac . Ca al. Today 2011,175, 100–105. [C ossRe ]
11.
Obalo
á
, L.; Pacul o
á
, K.; Balab
á
no
á
, J.; Ji
á
o
á
, K.; Bas l, Z.; Val
á
ško
á
, M.; Lacn
ý
, Z.; Ko anda, F.
E ec o Mn/Al a io in Co–Mn–Al mixed oxide ca alys s p epa ed om hyd o alci e-like p ecu so s on
ca aly ic decomposi ion o N2O. Ca al. Today 2007,119, 233–238. [C ossRe ]
12.
Ram
í
ez, J.P.; Kap eijn, F.; Schö el, K.; Moulijn, J.A. Fo ma ion and con ol o N2O in ni ic acid p oduc ion:
Whe e do we s and oday? Appl. Ca al. B En i on. 2003,44, 117–151. [C ossRe ]
13.
Kap eijn, F.; Ma b
á
n, G.; Mi asol, J.R.; Moulijn, J.A. Kine ic Analysis o he Decomposi ion o Ni ous Oxide
o e ZSM 5 Ca alys s. J. Ca al. 1997,167, 256–265. [C ossRe ]
14.
Asano, K.; Ohnishi, C.; Iwamo o, S.; Shioya, Y.; Inoue, M. Po assium-doped Co3O4 ca alys o di ec
decomposi ion o N2O. Appl. Ca al. B En i on. 2008,78, 242–249. [C ossRe ]
15.
Maniak, G.; S elmachowski, P.; Zasada, F.; Pisko z, W.; Ko a ba, A.; Sojka, Z. Guidelines o op imiza ion
o ca aly ic ac i i y o 3d ansi ion me al oxide ca alys s in N2O decomposi ion by po assium p omo ion.
Ca al. Today 2011,176, 369–372. [C ossRe ]
16.
Maniak, G.; S elmachowski, P.; S anek, J.J.; Ko a ba, A.; Sojka, Z. Ca aly ic p ope ies in N2O decomposi ion
o mixed cobal –i on spinels. Ca al. Commun. 2011,15, 127–131. [C ossRe ]
17.
S elmachowski, P.; Maniak, G.; Ko a ba, A.; Sojka, Z. S ong elec onic p omo ion o Co3O4 owa ds N2O
decomposi ion by su ace alkali dopan s. Ca al. Commun. 2009,10, 1062–1065. [C ossRe ]
18.
Cheng, H.; Huang, Y.; Wang, A.; Li, L.; Wang, X.; Zhang, T. N2O decomposi ion o e K-p omo ed Co-Al
ca alys s p epa ed om hyd o alci e-like p ecu so s. Appl. Ca al. B En i on. 2009,89, 391–397. [C ossRe ]
19.
Zhang, X.; Shen, Q.; He, C.; Wang, Y.; Cheng, J.; Hao, Z. CoMOR zeoli e ca alys p epa ed by bu e ed ion
exchange o e ec i e decomposi ion o ni ous oxide. J. Haza d. Ma e .
2011
,192, 1756–1765. [C ossRe ]
[PubMed]
20.
Pasha, N.; Lingaiah, N.; Babu, N.S.; Reddy, P.S.S.; P asad, P.S. S udies on cesium doped cobal oxide ca alys s
o di ec N2O decomposi ion in he p esence o oxygen and s eam. Ca al. Commun.
2008
,10, 132–136.
[C ossRe ]
21.
Da C uz, R.; Masca enhas, A.; And ade, H.M.C. Co-ZSM-5 ca alys s o N2O decomposi ion. Appl. Ca al.
B En i on. 1998,18, 223–231. [C ossRe ]
22.
Shen, Q.; Li, L.; Li, J.; Tian, H.; Hao, Z. A s udy on N2O ca aly ic decomposi ion o e Co/MgO ca alys s.
J. Haza d. Ma e . 2009,163, 1332–1337. [C ossRe ] [PubMed]
23.
Ka
á
sko
á
, K.; Obalo
á
, L.; Ji
á
o
á
, K.; Ko anda, F. E ec o p omo e s in Co–Mn–Al mixed oxide ca alys
on N2O decomposi ion. Chem. Eng. J. 2010,160, 480–487. [C ossRe ]
24.
Klyushina, A.; Pacul o
á
, K.; Ka
á
sko
á
, K.; Ji
á
o
á
, K.; Ri z, M.; F id icho
á
, D.; Voloda skaja, A.;
Obalo
á
, L. E ec o p epa a ion me hod on ca aly ic p ope ies o Co-Mn-Al mixed oxides o N2O
decomposi ion. J. Mol. Ca al. A Chem. 2016,425, 237–247. [C ossRe ]
25.
Campa, M.C.; Indo ina, V.; Pie ogiacomi, D. The dependence o ca aly ic ac i i y o N2O decomposi ion
on he exchange ex en o cobal o coppe in Na-MOR, H-MOR and Na-MFI. Appl. Ca al. B En i on.
2009
,
91, 347–354. [C ossRe ]
26.
Fellah, M.F.; Onal, I. N2O decomposi ion on Fe- and Co-ZSM-5: A densi y unc ional s udy. Ca al. Today
2008,137, 410–417. [C ossRe ]
Ca alys s 2020,10, 1398 20 o 21
27.
Obalo
á
, L.; Ka
á
sko
á
, K.; Ji
á
o
á
, K.; Ko anda, F. E ec o po assium in calcined Co–Mn–Al laye ed double
hyd oxide on he ca aly ic decomposi ion o N2O. Appl. Ca al. B En i on. 2009,90, 132–140. [C ossRe ]
28.
S elmachowski, P.; Ciu a, K.; G zybek, G. Mo phology-dependen eac i i y o cobal oxide nanopa icles in
N2O decomposi ion. Ca al. Sci. Technol. 2016,6, 5554–5560. [C ossRe ]
29.
Gudyka, S.; G zybek, G.; G ybo´s, J.; Indyka, P.; Leszczy´nski, B.; Ko a ba, A.; Sojka, Z. Enhancing he deN2O
ac i i y o he suppo ed Co3O4|
α
-Al2O3 ca alys by glyce ol-assis ed shape enginee ing o he ac i e phase
a he nanoscale. Appl. Ca al. B En i on. 2017,201, 339–347. [C ossRe ]
30.
G zybek, G.; W
ó
jcik, S.; Legu ko, P.; G ybo´s, J.; Indyka, P.; Leszczy´nski, B.; Ko a ba, A.; Sojka, Z. The mal
s abili yand epa i ion o po assium p omo e be ween he suppo andac i e phasein heKCo2.6Zn0.4O4|
α
Al2O3 ca alys o N2O decomposi ion: C ucial ole o ac i a ion empe a u e on ca aly ic pe o mance.
Appl. Ca al. B En i on. 2017,205, 597–604. [C ossRe ]
31.
Bo o´n, P.; Chmiela z, L.; Casale, S.; Cale s, C.; K a , J.-M.; Dzwigaj, S. E ec o Co con en on he ca aly ic
ac i i y o CoSiBEA zeoli es in N2O decomposi ion and SCR o NO wi h ammonia. Ca al. Today
2015
,258,
507–517. [C ossRe ]
32.
Liu, N.; Zhang, R.; Chen, B.; Li, Y.; Li, Y. Compa a i e s udy on he di ec decomposi ion o ni ous oxide
o e M (Fe, Co, Cu)–BEA zeoli es. J. Ca al. 2012,294, 99–112. [C ossRe ]
33.
Smee s, P.J.; Meng, Q.; Co hals, S.; Leeman, H.; Schoonheyd , R.A. Co–ZSM-5 ca alys s in he decomposi ion
o N2O and he SCR o NO wi h CH4: In luence o p epa a ion me hod and cobal loading. Appl. Ca al.
B En i on. 2008,84, 505–513. [C ossRe ]
34.
Ghah i, A.; Golbabaei, F.; Va ajoo, L.; Mi eskanda i, S.M.; Yase i, M.; Shah ahe i, S.J. Remo al o G eenhouse
Gas (N2O) by Ca aly ic Decomposi ion on Na u al Clinop iloli e Zeoli es Imp egna ed wi h Cobal . In . J.
En i on. Res. 2017,11, 327–337. [C ossRe ]
35.
Obalo
á
, L.; Ka
á
sko
á
, K.; Wach, A.; Kus owski, P.; Ku l
á
ko
á
, K.M.; Michalik, S.; Ji
á
o
á
, K. Alkali me als
as p omo e s in Co–Mn–Al mixed oxide o N2O decomposi ion. Appl. Ca al. A Gen.
2013
,462–463, 227–235.
[C ossRe ]
36.
Abu-Zied, B.M.; Soliman, S.A.; Abdellah, S.E. Pu e and Ni-subs i u ed Co3O4 spinel ca alys s o di ec N2O
decomposi ion. Chin. J. Ca al. 2014,35, 1105–1112. [C ossRe ]
37. Del Río, L.; Ma bán, G. S ainless s eel wi e mesh suppo ed po assium doped cobal oxide ca alys s o he
ca aly ic decomposi ion o ni ous oxide. Appl. Ca al. B En i on. 2012,126, 39–46. [C ossRe ]
38.
Ka
á
sko
á
, K.; Obalo
á
, L.; Ko anda, F. N2O ca aly ic decomposi ion and empe a u e p og ammed
deso p ion es s on alkali me als p omo ed Co–Mn–Al mixed oxide. Ca al. Today
2011
,176, 208–211.
[C ossRe ]
39.
Žane a, C.; Obalo
á
, L.; Ko anda, F.; Legu , D.; Ti o , A.; Ri z, M.; F id icho
á
, D.; Michalik, S.; Ku´s owski, P.;
Ji
á
o
á
, K. E ec o p ecu so syn hesis on ca aly ic ac i i y o Co3O4 in N2O decomposi ion. Ca al. Today
2015,257, 18–25. [C ossRe ]
40.
Xue, L.; Zhang, C.; He, H.; Te aoka, Y. Ca aly ic decomposi ion o N2O o e CeO2 p omo ed Co3O4 spinel
ca alys . Appl. Ca al. B En i on. 2007,75, 167–174. [C ossRe ]
41.
Pisko z, W.; Zasada, F.; S elmachowski, P.; Ko a ba, A.; Sojka, Z. Decomposi ion o N2O o e he su ace o
cobal spinel: A DFT accoun o eac i i y expe imen s. Ca al. Today 2008,137, 418–422. [C ossRe ]
42.
Xue, L.; Zhang, C.; He, H.; Te aoka, Y. P omo ion e ec o esidual K on he decomposi ion o N2O o e
cobal –ce ium mixed oxide ca alys . Ca al. Today 2007,126, 449–455. [C ossRe ]
43.
Klego a, A.; Inaya , A.; Indyka, P.; G ybo´s, J.; Sojka, Z.; Pacul o
á
, K.; Schwiege , W.; Voloda skaja, A.;
Ku´s owski, P.; Rokici´nska, A.; e al. Cobal mixed oxides deposi ed on he SiC open-cell oams o ni ous
oxide decomposi ion. Appl. Ca al. B En i on. 2019,255, 255. [C ossRe ]
44.
Iwanek, E.; K awczyk, K.; Pe yk, J.; Sobczak, J.W.; Kaszku , Z. Di ec ni ous oxide decomposi ion wi h
CoOx CeO2 ca alys s. Appl. Ca al. B En i on. 2011,106, 416–422. [C ossRe ]
45.
Thanga elu, K.; Pa ameswa i, K.; Kuppusamy, K.; Haldo ai, Y. A simple and acile me hod o syn hesize
Co3O4 nanopa icles om me al benzoa e dihyd azina e complex as a p ecu so . Ma e . Le .
2011
,65,
1482–1484. [C ossRe ]
46.
Russo, N.; Fino, D.; Sa acco, G.; Specchia, V. N2O ca aly ic decomposi ion o e a ious spinel- ype oxides.
Ca al. Today 2007,119, 228–232. [C ossRe ]
Ca alys s 2020,10, 1398 21 o 21
47.
G zybek, G.; S elmachowski, P.; Indyka, P.; Inge , M.; Wilk, M.; Ko a ba, A.; Sojka, Z. Cobal –zinc spinel
dispe sed o e co die i e monoli hs o ca aly ic N2O aba emen om ni ic acid plan s. Ca al. Today
2015
,
257, 93–97. [C ossRe ]
48.
Zhang, R.; Hedjazi, K.; Chen, B.; Li, Y.; Lei, Z.; Liu, N. M(Fe, Co)-BEA washcoa ed honeycomb co die i e o
N 2 O di ec decomposi ion. Ca al. Today 2016,273, 273–285. [C ossRe ]
49.
Ji
á
o
á
, K.; Balab
á
no
á
, J.; Ko anda, F.; Klego
á
, A.; Obalo
á
, L.; Fajga , R. Cobal Oxides Suppo ed
O e Ce ia–Zi conia Coa ed Co die i e Monoli hs as Ca alys s o Deep Oxida ion o E hanol and N2O
Decomposi ion. Ca al. Le . 2017,147, 1379–1391. [C ossRe ]
50.
Klyushina, A.; Pacul o
á
, K.; K ejˇco
á
, S.; Słowik, G.; Ji
á
o
á
, K.; Ko anda, F.; Ryczkowski, J.; Obalo
á
, L.
Ad an ages o s ainless s eel sie es as suppo o ca aly ic N2O decomposi ion o e K doped Co3O4.
Ca al. Today 2015,257 P 1, 2–10. [C ossRe ]
51.
Klego
á
, A.; Pacul o
á
, K.; F id icho
á
, D.; Voloda skaja, A.; Ko anda, F.; Ji
á
o
á
, K. Cobal Oxide Ca alys s
on Comme cial Suppo s o N2O Decomposi ion. Chem. Eng. Technol. 2017,40, 981–990. [C ossRe ]
52.
Pacul o
á
, K.; Klego a, A.; Kiška, T.; F id icho
á
, D.; Ma aus, A.; Rokici´nska, A.; Ku´s owski, P.; Obalo
á
, L.
E ec o suppo on he ca aly ic ac i i y o Co3O4-Cs deposi ed on open-cell ce amic oams o N2O
decomposi ion. Ma e . Res. Bull. 2020,129, 110892. [C ossRe ]
53.
Ru kowska, M.; Piwowa ska, Z.; Micek, E.; Chmiela z, L. Hie a chical Fe-, Cu- and Co-Be a zeoli es
ob ained by meso empla e- ee me hod. Pa I: Syn hesis and ca aly ic ac i i y in N2O decomposi ion.
Mic opo ous Mesopo ous Ma e . 2015,209, 54–65. [C ossRe ]
54.
Sadek, R.; Chalupka, K.A.; Mie czynski, P.; Rynkowski, J.; Gu gul, J.; Dzwigaj, S. Cobal Based Ca alys s
Suppo ed on Two Kinds o Be a Zeoli e o Applica ion in Fische -T opsch Syn hesis. Ca alys s
2019
,9, 497.
[C ossRe ]
55.
Kang, S.-H.; Ryu, J.-H.; Kim, J.-H.; Jang, I.H.; Kim, A.R.; Han, G.Y.; Bae, J.W.; Ha, K.-S. Role o ZSM5
Dis ibu ion on Co/SiO2 Fische –T opsch Ca alys o he P oduc ion o C5–C22 Hyd oca bons. Ene gy Fuels
2012,26, 6061–6069. [C ossRe ]
56.
Ku ian, M.; Thankachan, S.; Nai , D.S.; Aswa hy, E.K.; Babu, A.; Thomas, A.; KT, B.K. S uc u al, magne ic,
and acidic p ope ies o cobal e i e nanopa icles syn hesised by we chemical me hods. J. Ad . Ce am.
2015,4, 199–205. [C ossRe ]
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