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Nanostructured f-block element bimetallic oxides as catalysts for the conversion of
carbon dioxide
CaReCI Project Final Seminar
“Sustainable and efficient carbon capture for the cement industry”
Ana C. Ferreira 8th October 2019
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Valorization of C1 gaseous pollutants, e.g. CO2 for the
production of methane and methanol.
However, captured CO2 could be converted into fuels and chemicals using approaches such as
dry reforming of methane for synthesis gas production, or CO2 hydrogenation to hydrocarbons
or alcohols.
The carbon dioxide (CO2) concentration in the atmosphere
continues to rise with negative environmental effects such as
global average temperature (global warming) due to the
greenhouse effect and ocean acidification.
The most commonly studied technology to reduce CO2
emissions is Carbon Capture and Sequestration (CCS), which
consists of CO2 capture, transportation, and underground
storage.
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HYDROGENATION OF
Reduction agent: hydrogen
Main products: Methane, Methanol, long-chain hydrocarbons
𝐶𝑂2 + 4𝐻2 → 𝐶𝐻4+ 2𝐻2𝑂
𝐶𝑂2+ 3𝐻2 → 𝐶𝐻3𝑂𝐻 + 𝐻2𝑂
H298K=-164.7 kJ/mol
𝑛𝐶𝑂2+ 3𝑛𝐻2 → 𝐶𝑛𝐻2𝑛 + 2𝑛𝐻2𝑂 H298K=-128 kJ/mol
H298K=-49.8 kJ/mol
Hydrocarbons
Alcohols…
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Intermetallic precursors
(BET
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6
Powder XRD
BET
H2-Temperature Programmed Reduction
CO2-Temperature Programmed Desorption
Dehydrogenation/dehydration of 2-propanol
SEM-EDS
TEM
H2-TPR
CO2-TPD
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7
600nm
Ni-Ce
10 ºC/min
1 ºC/min
Particles size< 50 nm
Fibers size230 ± 120 nm
Ana C. Ferreira, Joaquim B. Branco, Int. J. Hydrogen Energy 44 (2019) 6505-6513
EDS mapping shows that all Ni-Ln nanofibers and nanoparticles present a homogeneous distribution of metals.
Good Ni/Ln ratio (Ni/Ln=5) ; Surface area ≈ 32 m2/g
Ni-La; Ni-Ce, Ni-Sm- Ni-Dy and Ni-Yb
Ni
Ce
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Ni-Ce/SiO2
Electrospun TEOS/PVP SiO2 Impregnated SiO2
Joaquim B. Branco, Pedro E. Brito, Ana C. Ferreira, Chemical Engineering Journal 380 (2020) 122465
Electrospun TEOS/PVP SiO2 Impregnated SiO2100-200 nm
< 1 μm
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Ana C. Ferreira, Joaquim B. Branco, Int. J. Hydrogen Energy 44 (2019) 6505-6513 Joaquim B. Branco, Pedro E. Brito, Ana C. Ferreira, Chemical Engineering Journal 380 (2020) 122465
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X-ray diffraction analysis confirms the presence of NiO (cubic phase) and
only the diffraction patterns of CeO2 were detected.
The diffraction patterns of the other f-block elements oxides were not
detected, either before or after the reaction.
XRD Ni-Ln nanofibers 800 ºC
XRD supported Ni-Ln 550 ºC
NiO crystallite size :
NiO around 30 nmDecrease with lanthanide:La 19 nm ; Ce 21 nm ; Sm 19 nm ; Dy 16 nm ; Yb 18 nm
NiO crystallite size :
NiO around 31 nmDecrease with lanthanide:La 22 nm ; Ce 18 nm ; Pr 13 nm; Sm 20 nm ; Dy 16 nm ; Yb 22 nm
0
1000
2000
3000
4000
5000
6000
20 30 40 50 60 70 80
Inte
nsi
ty (a.u.)
2 Theta (degree)
NiO LaNiO3 CeO2 Sm2O3 Dy2O3 Yb2O3
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0
150
300
450
600
200 250 300 350 400 450 500 550 600 650 700
TC
D S
ign
al (a.u./g cat)
T (ºC)
La-Ni Ce-Ni Sm-Ni Dy-Ni Yb-Ni NiO
392
365
389
531
398324
405
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Ni-Ln nanofibers
The addition of lanthanides to the catalyst composition improves the NiO oxygen lability (decreases the maximum reduction temperature, Tm).
Ni-Ln nanofibers: The reduction of the nickel-4f block element bimetallic oxides starts at 325 and is complete at 450 ºC: Ce < La < Sm < Dy < Yb
Supported Ni-Ln: Reduction temperatures maximum depends on the lanthanide: Sm < La < Pr < Yb < Dy < Ce
Ni2+ Ni0
LaNiO3 La2O3
Ni2+ Ni 0
Supported Ni-Ln microspheres
Ni-Sm
Ni-Yb
Ni-Dy
Ni-Ce
Ni
Ni-La
Ni-Pr
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Experimental conditionsMETHANE PRODUCTION
Reator “Plug flow” type
Atmospheric pressure
Reagents ratio: H2/CO2 = 4
Trection = 250 to 450 C
GHSV = 15 L CO2/gcat.h
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Ana C. Ferreira, Joaquim B. Branco, Int. J. Hydrogen Energy 44 (2019) 6505-6513 Joaquim B. Branco, Pedro E. Brito, Ana C. Ferreira, Chemical Engineering Journal 380 (2020) 122465
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The most of bimetallic oxides present a catalytic activity superior to that of a commercial rhodium catalyst (36% CH4 yield at 350 ºC)supported on alumina (5 wt. % Rh/Al2O3) one of today best catalyst for the methanation of carbon dioxide
Higher selectivities to methane (>97%).
Ana C. Ferreira, Joaquim B. Branco, Int. J. Hydrogen Energy 44 (2019) 6505-6513 ; Joaquim B. Branco, Pedro E. Brito, Ana C. Ferreira, Chemical Engineering Journal 380 (2020) 122465
0
10
20
30
40
50
60
200 250 300 350 400 450 500
Yie
ld C
H4
(%)
T (ºC)
Ni La-Ni Ce-Ni Sm-Ni Dy-Ni Yb-Ni
No reduced catalysts
0
10
20
30
40
50
200 250 300 350 400 450 500
Yie
ld C
H4
(%)
T (ºC)
Ni/SiO2 Ni-La/SiO2 Ni-Ce/SiO2 Ni-Pr/SiO2Ni-Sm/SiO2 Ni-Dy/SiO2 Ni-Yb/SiO2
Effect of temperature
Ni < Yb < La < Sm < Dy ≈ Ce < Pr Ni < Yb < La < Sm ≈ Dy < Ce
Ni-Ln nanofibers Supported Ni-Ln microspheres
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Effect of pre reduction treatment
Treaction=300 °C
1
6
12
9
7
9 9
1
910
14
11
8
4
0
2
4
6
8
10
12
14
16
Ni/SiO2 Ni-La Ni-Ce Ni-Pr Ni-Sm Ni-Dy Ni-Yb
Yie
ld C
H4
(%)
Catalyst
with pre-reduction without pre-reduction
The influence of this pre-treatment proved also to be positive in the case of Ni-Ln nanofibers.
Supported catalysts: Effect is neutral or negative since the reduction of NiO and formation of Ni occurs at lower temperatures.
The increase of the number of active sites at the catalyst's surface during reaction without the need of a pre-reduction treatment that occurs in situ during the reaction.
Higher effect of the catalysts with higher Treduction (H2-TPR results).
7
20
14
26 26
11 12
7
2 10
10
20
30
40
50
La-Ni Ce-Ni Sm-Ni Dy-Ni Yb-Ni
Yie
ld C
H4
(%)
Catalyst
with pre-reduction without pre-reduction
Ni-Ln nanofibers Supported Ni-Ln microspheres
Ana C. Ferreira, Joaquim B. Branco, Int. J. Hydrogen Energy 44 (2019) 6505-6513 ; Joaquim B. Branco, Pedro E. Brito, Ana C. Ferreira, Chemical Engineering Journal 380 (2020) 122465
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Influence of NiO particle size
Pr < Dy < Ce < Sm < La = Yb
The existence of a correlation between the size of the NiO
particles and the catalysts activity.
There is an inverse dependence between the catalyst
activity and the size of NiO active site crystallites.
Interaction/synergism between Ni and lanthanide oxides is
real.
For Ni-Ln nanofibers this influence is not so evident
(nanofibers or NiO crystallites size).
Joaquim B. Branco, Pedro E. Brito, Ana C. Ferreira, Chemical Engineering Journal 380 (2020) 122465
203
1,4031,533
2,109
1,682
1,274
562
31
22 18
13
20
16
22
10
15
20
25
30
35
0
500
1000
1500
2000
2500
Ni/SiO2 Ni-La Ni-Ce Ni-Pr Ni-Sm Ni-Dy Ni-Yb
Siz
e(n
m)
Yie
ld C
H4
(mL
/g.h
)
Yield Size
Treaction= 300 ºC Supported Ni-Ln microspheres
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15
Influence of basicity
Correlation between the catalysts basicity and its activity for themethanation of CO2, except for lanthanum.
Addition of f-block elements influence the acid-base propertiesenhancing the activity and stability of the catalysts.
CO2 adsorbs on sites of mild and high basicity to form covalentcarbonates, hydrogen carbonates and bidentate carbonates thatsubsequently reacts with H atoms on the surface of NiO particlesto form formate species and release CH4.
Joaquim B. Branco, Pedro E. Brito, Ana C. Ferreira, Chemical Engineering Journal 380 (2020) 122465
0
5
10
15
20
25
30
0
200
400
600
800
1000
1200
1400
Ni-La Ni-Ce Ni-Pr Ni-Sm Ni-Dy Ni-Yb
Ba
sic
ity (a/
p)
Ac
tivit
y (
mL
CH
4/g
.h)
Activity Basicity
Treaction= 300 ºC
Basicity 2-propanol at T= 250 ºC, He
Supported Ni-Ln microspheres
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Catalysts Stability
Ni-Dy nanofibers
Deactivation resistance for at least 60-80 h in the gaseous stream, whichis strongly unusual for nickel-based catalysts.
Low carbon deposition (< 1 wt.%)
Lanthanide contribute
350 ºC
400 ºC
300 ºC
450 ºC
350 ºC
0
10
20
30
40
50
0 12 24 36 48 60 72 84
Yie
ld C
H4
(%)
t (h)
Ni-Ce/SiO2 microspheres
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Electrospinning is a good technique to produce nanocatalysts: with or without support.
All catalysts tested presented a high selectivity to methane (> 97%) at atmospheric pressure and low
temperatures.
The best results were those obtained with the Ni-Ce and Ni-Dy compounds, for nanofibers and Ni-Pr and Ni-Ce
for the supported on silica.
All bimetallic oxides (nanofibers) present a catalytic activity superior to that of a commercial rhodium catalyst
supported on alumina (5 wt % Rh/Al2O3) one of today best catalyst for the methanation of carbon dioxide.
The nickel-4f block element nanofibers or supported on sílica present a deactivation resistance for at least 50 h
in the gaseous stream, which is strongly unusual for nickel-based catalysts.
Basicity, dispersion, and accessibility to the active sites are also important factors that can condition the activity
of the catalysts.
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FCT (Fundaçao para a Ciência e a Tecnologia) supportthrough the UID/Multi/04349/2013 project.
Dr. Joaquim B. BrancoPedro E. Brito (Master Student)“IOARC” group
Campus Tecnológico e Nuclear do Instituto Superior Técnico
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