Characterization and catalytic activity of soft-templated NiO-CeO2 mixed oxides for CO and CO2 co-methanation
Luciano Atzori1, Maria Giorgia Cutrufello1, Daniela Meloni1, Barbara Onida2, Delia Gazzoli3, Andrea Ardu1, Roberto Monaci1, Maria Franca Sini1, Elisabetta Rombi1()
1. Department of Chemical and Geological Sciences, University of Cagliari, 09042 Monserrato (CA), Italy 2. Department of Materials Science and Chemical Engineering, CR-INSTM for Materials with Controlled Porosity, Polytechnic of Turin, 10129 Turin, Italy 3. Department of Chemistry, University of Rome “La Sapienza”, 00185 Rome, Italy
Nanosized NiO, CeO2 and NiO-CeO2 mixed oxides with different Ni/Ce molar ratios were prepared by the soft template method. All the samples were characterized by different techniques as to their chemical composition, structure, morphology and texture. On the catalysts submitted to the same reduction pretreatment adopted for the activity tests the surface basic properties and specific metal surface area were also determined. NiO and CeO2 nanocrystals of about 4 nm in size were obtained, regardless of the Ni/Ce molar ratio. The Raman and X-ray photoelectron spectroscopy results proved the formation of defective sites at the NiO-CeO2 interface, where Ni species are in strong interaction with the support. The microcalorimetric and Fourier transform infrared analyses of the reduced samples highlighted that, unlike metallic nickel, CeO2 is able to effectively adsorb CO2, forming carbonates and hydrogen carbonates. After reduction in H2 at 400 °C for 1 h, the catalytic performance was studied in the CO and CO2 co-methanation reaction. Catalytic tests were performed at atmospheric pressure and 300 °C, using CO/CO2/H2 molar compositions of 1/1/7 or 1/1/5, and space velocities equal to 72000 or 450000 cm3∙h–1∙gcat–1. Whereas CO was almost completely hydrogenated in any investigated experimental conditions, CO2 conversion was strongly affected by both the CO/CO2/H2 ratio and the space velocity. The faster and definitely preferred CO hydrogenation was explained in the light of the different mechanisms of CO and CO2 methanation. On a selected sample, the influence of the reaction temperature and of a higher number of space velocity values, as well as the stability, were also studied. Provided that the Ni content is optimized, the NiCe system investigated was very promising, being highly active for the COx co-methanation reaction in a wide range of operating conditions and stable (up to 50 h) also when submitted to thermal stress.
. [J]. Frontiers of Chemical Science and Engineering, 2021, 15(2): 251-268.
Luciano Atzori, Maria Giorgia Cutrufello, Daniela Meloni, Barbara Onida, Delia Gazzoli, Andrea Ardu, Roberto Monaci, Maria Franca Sini, Elisabetta Rombi. Characterization and catalytic activity of soft-templated NiO-CeO2 mixed oxides for CO and CO2 co-methanation. Front. Chem. Sci. Eng., 2021, 15(2): 251-268.
IPCC 2013: Summary for policymakers. In: Stocker T F, Qin D, Plattner G K, Tignor M, Allen S K, Boschung J, Nauels A, Xia Y, Bex V, Midgley P M, eds. Climate Change 2013: the Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK and New York, USA: Cambridge University Press, 2013
2
M Aresta, A Dibenedetto, A Angelini. The use of solar energy can enhance the conversion of carbon dioxide into energy-rich products: stepping towards artificial photosynthesis. Philosophy Transactions of the Royal Society A, 2013, 371(1996): 20120111 https://doi.org/10.1098/rsta.2012.0111
3
CO2 Emission from Fuel Combustion Highlights. 2016 ed. Paris: International Energy Agency (IEA) Publications, 2016
4
M Aresta, A Dibenedetto, A Angelini. Catalysis for the valorization of exhaust carbon: from CO2 to chemicals, materials, and fuels. Technological use of CO2. Chemical Reviews, 2014, 114(3): 1709–1742 https://doi.org/10.1021/cr4002758
5
Y Wolde-Rufael, S Idowu. Income distribution and CO2 emission: a comparative analysis for China and India. Renewable & Sustainable Energy Reviews, 2017, 74: 1336–1345 https://doi.org/10.1016/j.rser.2016.11.149
6
J Gao, Q Liu, F Gu, B Liu, Z Zhong, F Su. Recent advances in methanation catalysts for the production of synthetic natural gas. RSC Advances, 2015, 5(29): 22759–22776 https://doi.org/10.1039/C4RA16114A
M A A Aziz, A A Jalil, S Triwahyono, A Ahmada. CO2 methanation over heterogeneous catalysts: recent progress and future prospects. Green Chemistry, 2015, 17(5): 2647–2663 https://doi.org/10.1039/C5GC00119F
9
S D Senanayake, J Evans, S Agnoli, L Barrio, T L Chen, J Hrbek, J A Rodriguez. Water-gas shift and CO methanation reactions over Ni-CeO2(111) catalysts. Topics in Catalysis, 2011, 54(1-4): 34–41 https://doi.org/10.1007/s11244-011-9645-6
10
J Carrasco, L Barrio, P Liu, J A Rodriguez, M V Ganduglia-Pirovano. Theoretical studies of the adsorption of CO and C on Ni(111) and Ni/CeO2(111): evidence of a strong metal-support interaction. Journal of Physical Chemistry C, 2013, 117(16): 8241–8250 https://doi.org/10.1021/jp400430r
11
E Rombi, M G Cutrufello, L Atzori, R Monaci, A Ardu, D Gazzoli, P Deiana, I Ferino. CO methanation on Ni-Ce mixed oxides prepared by hard template method. Applied Catalysis A, General, 2016, 515: 144–153 https://doi.org/10.1016/j.apcata.2016.02.002
12
Y Liu, L Zhu, X Wang, S Yin, F Leng, F Zhang, H Lin, S Wang. Catalytic methanation of syngas over Ni-based catalysts with different supports. Chinese Journal of Chemical Engineering, 2017, 25(5): 602–608 https://doi.org/10.1016/j.cjche.2016.10.019
13
T A Le, T W Kim, S H Lee, E D Park. Effects of Na content in Na/Ni/SiO2 and Na/Ni/CeO2 catalysts for CO and CO2 methanation. Catalysis Today, 2018, 303: 159–167 https://doi.org/10.1016/j.cattod.2017.09.031
14
S Tada, T Shimizu, H Kameyama, T Haneda, R Kikuchi. Ni/CeO2 catalysts with high CO2 methanation activity and high CH4 selectivity at low temperatures. International Journal of Hydrogen Energy, 2012, 37(7): 5527–5531 https://doi.org/10.1016/j.ijhydene.2011.12.122
15
G Zhou, H Liu, K Cui, A Jia, G Hu, Z Jiao, Y Liu, X Zhang. Role of surface Ni and Ce species of Ni/CeO2 catalyst in CO2 methanation. Applied Surface Science, 2016, 383: 248–252 https://doi.org/10.1016/j.apsusc.2016.04.180
16
L Atzori, M G Cutrufello, D Meloni, R Monaci, C Cannas, D Gazzoli, M F Sini, P Deiana, E Rombi. CO2 methanation on hard-templated NiO-CeO2 mixed oxides. International Journal of Hydrogen Energy, 2017, 42(32): 20689–20702 https://doi.org/10.1016/j.ijhydene.2017.06.198
17
L Atzori, M G Cutrufello, D Meloni, C Cannas, D Gazzoli, R Monaci, M F Sini, E Rombi. Highly active NiO-CeO2 catalysts for synthetic natural gas production by CO2 methanation. Catalysis Today, 2018, 299: 183–192 https://doi.org/10.1016/j.cattod.2017.05.065
18
S Ratchahat, M Sudoh, Y Suzuki, W Kawasaki, R Watanabe, C Fukuhara. Development of a powerful CO2 methanation process using a structured Ni/CeO2 catalyst. Journal of CO2 Utilization, 2018, 24: 210–219
19
S Malwadkar, P Bera, M S Hegde, C V V Satyanarayana. Preferential oxidation of CO on Ni/CeO2 catalysts in the presence of excess H2 and CO2. Reaction Kinetics, Mechanisms and Catalysis, 2012, 107(2): 405–419 https://doi.org/10.1007/s11144-012-0477-6
20
T Zyryanova, P V Snytnikov, R V Gulyaev, Y Amosov, A I Boronin, V A Sobyanin. Performance of Ni/CeO2 catalysts for selective CO methanation in hydrogen-rich gas. Chemical Engineering Journal, 2014, 238: 189–197 https://doi.org/10.1016/j.cej.2013.07.034
21
B Nematollahi, M Rezaei, E Nemati Lay. Preparation of highly active and stable NiO-CeO2 nanocatalysts for CO selective methanation. International Journal of Hydrogen Energy, 2015, 40(27): 8539–8547 https://doi.org/10.1016/j.ijhydene.2015.04.127
22
B Nematollahi, M Rezaei, E Nemati Lay. Selective methanation of carbon monoxide in hydrogen rich stream over Ni/CeO2 nanocatalysts. Journal of Rare Earths, 2015, 33(6): 619–628 https://doi.org/10.1016/S1002-0721(14)60462-2
23
M V Konishcheva, D I Potemkin, P V Snytnikov, M M Zyryanova, V P Pakharukova, P A Simonov, V A Sobyanin. Selective CO methanation in H2-rich stream over Ni-, Co- and Fe/CeO2: effect of metal and precursor nature. International Journal of Hydrogen Energy, 2015, 40(40): 14058–14063 https://doi.org/10.1016/j.ijhydene.2015.07.071
24
M V Konishcheva, D I Potemkin, S D Badmaev, P V Paukshtis, V A Sobyanin, V N Parmon. On the mechanism of CO and CO2 methanation over Ni/CeO2 catalysts. Topics in Catalysis, 2016, 59(15-16): 1424–1430 https://doi.org/10.1007/s11244-016-0650-7
25
H Habazaki, M Yamasaki, B P Zhang, A Kawashima, S Kohno, T Takai, K Hashimoto. Co-methanation of carbon monoxide and carbon dioxide on supported nickel and cobalt catalysts prepared from amorphous alloys. Applied Catalysis A, General, 1998, 172(1): 131–140 https://doi.org/10.1016/S0926-860X(98)00121-5
26
M R Gogate, R J Davis. Comparative study of CO and CO2 hydrogenation over supported RhFe catalysts. Catalysis Communications, 2010, 11(10): 901–906 https://doi.org/10.1016/j.catcom.2010.03.020
27
J Gao, Y Wang, Y Ping, D Hu, G Xu, F Gu, F Su. A thermodynamic analysis of methanation reactions of carbon oxides for the production of synthetic natural gas. RSC Advances, 2012, 2(6): 2358–2368 https://doi.org/10.1039/c2ra00632d
28
Y H Huang, J J Wang, Z M Liu, G D Lin, H B Zhang. Highly efficient Ni-ZrO2 catalyst doped with Yb2O3 for co-methanation of CO and CO2. Applied Catalysis A, General, 2013, 466: 300–306 https://doi.org/10.1016/j.apcata.2013.06.021
29
R Razzaq, H Zhu, L Jiang, U Muhammad, C Li, S Zhang. Catalytic methanation of CO and CO2 in coke oven gas over Ni-Co/ZrO2-CeO2. Industrial & Engineering Chemistry Research, 2013, 52(6): 2247–2256 https://doi.org/10.1021/ie301399z
30
R Razzaq, C Li, N Amin, S Zhang, K Suzuki. Co-methanation of carbon oxides over nickelbased CexZr1–xO2 catalysts. Energy & Fuels, 2013, 27(11): 6955–6961 https://doi.org/10.1021/ef401049v
31
R Razzaq, C Li, M Usman, K Suzuki, S Zhang. A highly active and stable Co4N/gAl2O3 catalyst for CO and CO2 methanation to produce synthetic natural gas. Chemical Engineering Journal, 2015, 262: 1090–1098 https://doi.org/10.1016/j.cej.2014.10.073
32
Y Li, Q Zhang, R Chai, G Zhao, Y Liu, Y Lu. Structured Ni-CeO2-Al2O3/Ni-foam catalyst with enhanced heat transfer for substitute natural gas production by syngas methanation. ChemCatChem, 2015, 7(9): 1427–1431 https://doi.org/10.1002/cctc.201500086
33
K Zhao, Z Li, L Bian. CO2 methanation and co-methanation of CO and CO2 over Mn-promoted Ni/Al2O3 catalysts. Frontiers of Chemical Science and Engineering, 2016, 10(2): 273–280 https://doi.org/10.1007/s11705-016-1563-5
34
M Belimov, D Metzger, P Pfeifer. On the temperature control in a microstructured packed bed reactor for methanation of CO/CO2 mixtures. AIChE Journal. American Institute of Chemical Engineers, 2017, 63(1): 120–129 https://doi.org/10.1002/aic.15461
35
P Frontera, A Macario, A Malara, V Modafferi, M C Mascolo, S Candamano, F Crea, P Antonucci. CO2 and CO hydrogenation over Ni-supported materials. Functional Materials Letters (Singapore), 2018, 11(05): 1850061 https://doi.org/10.1142/S1793604718500613
36
L Atzori, E Rombi, D Meloni, M F Sini, R Monaci, M G Cutrufello. CO and CO2 Co-Methanation on Ni/CeO2-ZrO2 Soft-Templated Catalysts. Catalysts, 2019, 9(5): 415 https://doi.org/10.3390/catal9050415
37
Y Wang, J Ma, M Luo, P Fang, M He. Preparation of high-surface area nano-CeO2 by template-assisted precipitation method. Journal of Rare Earths, 2007, 25(1): 58–62 https://doi.org/10.1016/S1002-0721(07)60045-3
38
M F Luo, J M Ma, J Q Lu, Y P Song, Y J Wang. High-surface area CuO-CeO2 catalysts prepared by a surfactant-templated method for low-temperature CO oxidation. Journal of Catalysis, 2007, 246(1): 52–59 https://doi.org/10.1016/j.jcat.2006.11.021
39
C D Wagner, L E Davis, M V Zeller, J A Taylor, R H Raymond, L H Gale. Empirical atomic sensitivity factors for quantitative analysis by electron spectroscopy for chemical analysis. Surface and Interface Analysis, 1981, 3(5): 211–225 https://doi.org/10.1002/sia.740030506
40
H P Klug, L E Alexander. X-ray diffraction procedures: for polycrystalline and amorphous materials. 2nd ed. New York: John Wiley & Sons Inc., 1974, 687–703
41
F Rouquerol, J Rouquerol, K S W Sing, P Llewellyn, G Maurin. Adsorption by powders and porous solids: principles, methodology and applications. Amsterdam: Academic Press, 2014, 12–13
42
W H Weber, K C Bass, J R McBride. Raman study of CeO2: second-order scattering, lattice dynamics, and particle-size effects. Physical Review. B, 1993, 48(1): 178–185 https://doi.org/10.1103/PhysRevB.48.178
43
J E Spanier, R D Robinson, F Zheng, S W Chan, I P Herman. Size-dependent properties of CeO2−y nanoparticles as studied by Raman scattering. Physical Review. B, 2001, 64(24): 245407–245414 https://doi.org/10.1103/PhysRevB.64.245407
44
T Taniguchi, T Watanabe, N Sugiyama, A K Subramani, H Wagata, N Matsushita, M Yoshimura. Identifying defects in ceria-based nanocrystals by UV resonance Raman spectroscopy. Journal of Physical Chemistry C, 2009, 113(46): 19789–19793 https://doi.org/10.1021/jp9049457
45
N Mironova-Ulmane, A Kuzmin, I Steins, J Grabis, I Sildos, M Pärs. Raman scattering in nanosized nickel oxide NiO. Journal of Physics: Conference Series, 2007, 93: 012039–012043 https://doi.org/10.1088/1742-6596/93/1/012039
46
Z Wu, M Li, J Howe, H M Meyer III, S H Overbury. Probing defect sites on CeO2 nanocrystals with well-defined surface planes by Raman spectroscopy and O2 adsorption. Langmuir, 2010, 26(21): 16595–16606 https://doi.org/10.1021/la101723w
47
Y Gao, R Li, S Chen, L Luo, T Cao, W Huang. Morphology-dependent interplay of reduction behaviors, oxygen vacancies and hydroxyl reactivity of CeO2 nanocrystals. Physical Chemistry Chemical Physics, 2015, 17(47): 31862–31871 https://doi.org/10.1039/C5CP04570C
48
P Burroughs, A Hamnett, A F Orchard, G Thornton. Satellite structure in the X-ray photoelectron spectra of some binary and mixed oxides of lanthanum and cerium. Journal of the Chemical Society, Dalton Transactions: Inorganic Chemistry, 1976, 17(17): 1686–1698 https://doi.org/10.1039/dt9760001686
49
M Romeo, K Bak, J El Fallah, F Le Normand, L Hilaire. XPS study of the reduction of cerium dioxide. Surface and Interface Analysis, 1993, 20(6): 5008–5012 https://doi.org/10.1002/sia.740200604
50
J Z Shyu, K Otto, W L H Watkins, G W Graham, R K Belitz, H S Gandhi. Characterization of Pd/g-alumina catalysts containing ceria. Journal of Catalysis, 1988, 114(1): 23–33 https://doi.org/10.1016/0021-9517(88)90005-X
51
F Zhang, P Wang, J Koberstein, S Khalid, S W Chan. Cerium oxidation state in ceria nanoparticles studied with X-ray photoelectron spectroscopy and absorption near edge spectroscopy. Surface Science, 2004, 563(1-3): 74–82 https://doi.org/10.1016/j.susc.2004.05.138
52
L Qiu, F Liu, L Zhao, Y Ma, J Yao. Comparative XPS study of surface reduction for nanocrystalline and microcrystalline ceria powder. Applied Surface Science, 2006, 252(14): 4931–4935 https://doi.org/10.1016/j.apsusc.2005.07.024
53
A Allahgholi, J I Flege, S Thieß, W Drube, J Falta. Oxidation-state analysis of ceria by X-ray photoelectron spectroscopy. ChemPhysChem, 2015, 16(5): 1083–1091 https://doi.org/10.1002/cphc.201402729
54
A P Grosvenor, M C Biesinger, R S C Smart, N S McIntyre. New interpretations of XPS spectra of nickel metal and oxides. Surface Science, 2006, 600(9): 1771–1779 https://doi.org/10.1016/j.susc.2006.01.041
55
M Atanasov, D Reinen. Non-local electronic effects in core-level photoemission, UV and optical electronic absorption spectra of nickel oxides. Journal of Electron Spectroscopy and Related Phenomena, 1997, 86(1-3): 185–199 https://doi.org/10.1016/S0368-2048(97)00065-0
56
A F Carley, S D Jackson, J N O’Shea, M W Roberts. The formation and characterisation of Ni3+—An X-ray photoelectron spectroscopic investigation of potassium-doped Ni(110)-O. Surface Science, 1999, 440(3): L868–L874 https://doi.org/10.1016/S0039-6028(99)00872-9
57
S Mahammadunnisa, P Manoj Kumar Reddy, N Lingaiah, C Subrahmanyam. NiO/Ce1−xNixO2-d as an alternative to noble metal catalysts for CO oxidation. Catalysis Science & Technology, 2013, 3: 730–736 https://doi.org/10.1039/C2CY20641B
58
H Metiu, S Chrétien, Z Hu, B Li, X Y Sun. Chemistry of Lewis acid-base pairs on oxide surfaces. Journal of Physical Chemistry C, 2012, 116(19): 10439–10450 https://doi.org/10.1021/jp301341t
59
Z Wu, A K P Mann, M Li, S H Overbury. Spectroscopic investigation of surface-dependent acid-base property of ceria nanoshapes. Journal of Physical Chemistry C, 2015, 119(13): 7340–7350 https://doi.org/10.1021/acs.jpcc.5b00859
60
U Tumuluri, G Rother, Z Wu. Fundamental understanding of the interaction of acid gases with CeO2: from surface science to practical catalysis. Industrial & Engineering Chemistry Research, 2016, 55(14): 3909–3919 https://doi.org/10.1021/acs.iecr.5b05014
61
S C Yang, W N Su, J Rick, S D Lin, J Y Liu, C J Pan, J F Lee, B J Hwang. Oxygen vacancy engineering of cerium oxides for carbon dioxide capture and reduction. ChemSusChem, 2013, 6(8): 1326–1329 https://doi.org/10.1002/cssc.201300219
62
M Li, U Tumuluri, Z Wu, S Dai. Effect of dopants on the adsorption of carbon dioxide on ceria surfaces. ChemSusChem, 2015, 8(21): 3651–3660 https://doi.org/10.1002/cssc.201500899
63
A A Davydov. Basic sites on the surface of oxide catalysts responsible for oxidative methane coupling. Chemical Engineering & Technology, 1995, 18(1): 7–11 https://doi.org/10.1002/ceat.270180103
W S Dong, H S Roh, K W Jun, S E Park, Y S Oh. Methane reforming over Ni/Ce-ZrO2 catalysts: effect of nickel content. Applied Catalysis A, General, 2002, 226(1-2): 63–72 https://doi.org/10.1016/S0926-860X(01)00883-3
66
F Ocampo, B Louis, L Kiwi Minsker, A C Roger. Effect of Ce/Zr composition and noble metal promotion on nickel based CexZr1−xO2 catalysts for carbon dioxide methanation. Applied Catalysis A, General, 2011, 392(1-2): 36–44 https://doi.org/10.1016/j.apcata.2010.10.025
67
K W Jeon, J O Shim, W J Jang, D W Lee, H S Na, H M Kim, Y L Lee, S Y Yoo, H S Roh, B H Jeon, J W Bae, C H Ko. Effect of calcination temperature on the association between free NiO species and catalytic activity of Ni-Ce0.6Zr0.4O2 deoxygenation catalysts for biodiesel production. Renewable Energy, 2019, 131: 144–151 https://doi.org/10.1016/j.renene.2018.07.042
68
V Sharma, P A Crozier, R Sharma, J B Adams. Direct observation of hydrogen spillover in Ni-loaded Pr-doped ceria. Catalysis Today, 2012, 180(1): 2–8 https://doi.org/10.1016/j.cattod.2011.09.009
69
I Czekaj, F Loviat, F Raimondi, J Wambach, S Biollaz, A Wokaun. Characterization of surface processes at the Ni-based catalyst during the methanation of biomass-derived synthesis gas: X-ray photoelectron spectroscopy. Applied Catalysis A, General, 2007, 329: 68–78 https://doi.org/10.1016/j.apcata.2007.06.027
70
L Znak, K Stolecki, J Zieliński. The effect of cerium, lanthanum and zirconium on nickel/alumina catalysts for the hydrogenation of carbon oxides. Catalysis Today, 2005, 101(2): 65–71 https://doi.org/10.1016/j.cattod.2005.01.003
71
P A U Aldana, F Ocampo, K Kobl, B Louis, F Thibault-Starzyk, M Daturi, P Bazin, S Thomas, A C Roger. Catalytic CO2 valorization into CH4 on Ni-based ceria-zirconia. Reaction mechanism by operando IR spectroscopy. Catalysis Today, 2013, 215: 201–207 https://doi.org/10.1016/j.cattod.2013.02.019
72
H Muroyama, Y Tsuda, T Asakoshi, H Masitah, T Okanishi, T Matsui, K Eguchi. Carbon dioxide methanation over Ni catalysts supported on various metal oxides. Journal of Catalysis, 2016, 343: 178–184 https://doi.org/10.1016/j.jcat.2016.07.018
73
F Meng, X Li, X Lv, Z Li. CO hydrogenation combined with water-gas-shift reaction for synthetic natural gas production: a thermodynamic and experimental study. International Journal of Coal Science & Technology, 2018, 5(4): 439–451 https://doi.org/10.1007/s40789-017-0177-y
74
L Barrio, A Kubacka, G Zhou, M Estrella, A Martínez Arias, J C Hanson, M Fernández García, J A Rodriguez. Unusual physical and chemical properties of Ni in Ce1−xNixO2−y oxides: structural characterization and catalytic activity for the water gas shift reaction. Journal of Physical Chemistry C, 2010, 114(29): 12689–12697 https://doi.org/10.1021/jp103958u
75
S Alamolhoda, G Vitale, A Hassan, N N Nassar, P P Almao. synergetic effects of cerium and nickel in Ce-Ni-MFI catalysts on low-temperature water-gas shift reaction. Fuel, 2019, 237: 361–372 https://doi.org/10.1016/j.fuel.2018.09.096
76
S K Talkhoncheh, M Haghighi. Syngas production via dry reforming of methane over Ni-based nanocatalyst over various supports of clinoptilolite, ceria and alumina. Journal of Natural Gas Science and Engineering, 2015, 23: 16–25 https://doi.org/10.1016/j.jngse.2015.01.020
77
H Ay, D Üner. Dry reforming of methane over CeO2 supported Ni, Co and Ni-Co catalysts. Applied Catalysis B: Environmental, 2015, 179: 128–138 https://doi.org/10.1016/j.apcatb.2015.05.013
78
X Yan, Y Liu, B Zhao, Z Wang, Y Wang, C J Liu. Methanation over Ni/SiO2: effect of the catalyst preparation methodologies. International Journal of Hydrogen Energy, 2013, 38(5): 2283–2291 https://doi.org/10.1016/j.ijhydene.2012.12.024
79
T Mondal, K K Pant, A K Dalai. Catalytic oxidative steam reforming of bio-ethanol for hydrogen production over Rh-promoted Ni/CeO2-ZrO2 catalyst. International Journal of Hydrogen Energy, 2015, 40(6): 2529–2544 https://doi.org/10.1016/j.ijhydene.2014.12.070