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

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.

2

3

4

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

6

Powder XRD

BET

H2-Temperature Programmed Reduction

CO2-Temperature Programmed Desorption

Dehydrogenation/dehydration of 2-propanol

SEM-EDS

TEM

H2-TPR

CO2-TPD

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

8

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

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

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

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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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