Methane partial oxidation over NiO-MgO/Ce_0.75Zr_0.25O₂ catalysts

Abstract

Methane partial oxidation (MPO) is considered as an alternative method to produce hydrogen because it is an exothermic reaction to afford a suitable H₂/CO ratio of 2. However, carbon deposition on a catalyst is observed as a major cause of catalyst deactivation in MPO. In order to find suitable catalysts that prevent the carbon deposition, NiO-MgO/Ce_0.75Zr_0.25O₂ (CZO) supported catalysts were prepared via the co-impregnation (C) and sequential incipient wetness impregnation (S) methods. The amount of Ni loading was fixed at 15 wt-% whereas the amount of MgO loading was varied from 5 to 15 wt-%. The results revealed that the addition of MgO shifted the light-off temperatures to higher temperatures. This is because the Ni surface was partially covered with MgO, and the strong interaction between NiO and NiMgO₂ over CZO support led to the difficulty in reducing NiO to active Ni⁰ and thus less catalytic activity. However, among the catalysts tested, the 15Ni5Mg/CZO (S) catalyst exhibited the best catalytic stability for MPO after 18 h on stream at 750°C. Moreover, this catalyst had a better resistance to carbon deposition due to its high metallic Ni dispersion at high temperature.

Keywords

methane partial oxidation / NiO / ceria-zirconia / MgO / mixed oxide solid solution

References

[1] Dissanayake D, Rosynek M, Kharas K, Lunsford J. Partial oxidation of methane to carbon monoxide and hydrogen over a Ni/Al₂O₃ catalyst. Journal of Catalysis, 1991, 132(1): 117–127

[2] Lu Y, Xue J, Yu C, Liu Y, Shen S. Mechanistic investigations on the partial oxidation of methane to synthesis gas over a nickel-on-alumina catalyst. Applied Catalysis A, General, 1998, 174(1): 121–128

[3] Chellappa A, Viswanath D. Partial oxidation of methane using ferric molybdate catalyst. Industrial & Engineering Chemistry Research, 1995, 34(6): 1933–1940

[4] Au C T, Wang H Y, Wan H L. Mechanistic studies of CH₄/O₂ conversion over SiO₂-supported nickel and copper-catalysts. Journal of Catalysis, 1996, 158(1): 343–348

[5] Hu Y, Ruckenstein E. Binary MgO-based solid solution catalysis for methane conversion to syngas. Catalysis Reviews, 2002, 43(3): 423–453

[6] Boucouvalas Y, Zhang Z, Verykios X. Partial oxidation of methane to synthesis gas via the direct reaction scheme over Ru/TiO₂ catalyst. Catalysis Letters, 1996, 40(3): 189–195

[7] Boucouvalas Y, Zhang Z, Verykios X. Heat transport limitations and reaction scheme of partial oxidation of methane to synthesis gas over supported rhodium catalysts. Catalysis Letters, 1994, 27(1): 131–142

[8] Hickman D, Schmidt L. Production of syngas by direct catalytic oxidation of methane. Science, 1993, 259(5093): 343–346

[9] Hargreaves J, Hutching G, Joyner R. Control of product selectivity in the partial oxidation of methane. Nature, 1990, 348(6300): 428–429

[10] Irigoyen B, Castellani N, Juan A. Methane oxidation reactions on MoO₃(100): A theoretical study. Journal of Molecular Catalysis A Chemical, 1998, 129(2): 297–310

[11] Ruckenstein E, Hu Y. Methane partial oxidation over NiO/MgO solid solution catalysts. Applied Catalysis A, General, 1999, 183(1): 85–92

[12] Montoya J, Romero-Pascual E, Gimon C, Del Angle P, Monzon A. Methane reforming with CO₂ over Ni/ZrO₂-CeO₂ catalysts prepared by sol-gel. Catalysis Today, 2000, 63(1): 71–85

[13] Zhu T, Stephanopoulos M. Catalytic partial oxidation of methane to synthesis gas over Ni-CeO₂. Applied Catalysis A, General, 2001, 208(1-2): 403–417

[14] Pengpanich S, Meeyoo V, Rirksomboon T. Methane partial oxidation over Ni/CeO₂-ZrO₂ mixed oxide solid solution catalysts. Catalysis Today, 2004, 93-95: 95–105

[15] Pengpanich S, Meeyoo V, Rirksomboon T, Schwank J. Hydrogen production from partial oxidation of iso-octane over Ni/Ce₀.75Zr₀.25O₂ and Ni/β˝-Al₂O₃ catalysts. Applied Catalysis A, General, 2006, 302(1): 133–139

[16] Pengpanich S, Meeyoo V, Rirksomboon T, Schwank J. The effect of Nb loading on catalytic properties of Ni/Ce₀.75Zr₀.25O₂ catalyst for methane partial oxidation. Journal of Natural Gas Chemistry, 2007, 16(3): 227–234

[17] Tang S, Lin J, Tan K. Partial oxidation of methane to syngas over Ni/MgO, Ni/CaO and Ni/CeO₂. Catalysis Letters, 1998, 51(3-4): 169–175

[18] Qiu Y, Chen J, Zhang J. Effects of MgO promoter on properties of Ni/Al₂O₃ catalysts for partial oxidation of methane to syngas. Frontiers of Chemical Engineering in China, 2007, 1(2): 167–171

[19] Roh H, Jun K, Dong W, Chang J, Park S, Joe Y. Highly active and stable Ni/Ce-ZeO₂ catalyst for H₂ production from methane. Journal of Molecular Catalysis A Chemical, 2002, 181(1-2): 137–142

[20] Arena F, Fruster F, Parmaliana A, Plyasova L, Shmakov A. Effect of calcination on the structure of Ni/MgO catalyst: An X-ray diffraction study. Journal of the Chemical Society, Faraday Transactions, 1996, 92(3): 469–471

[21] Asencios Y, Nascente P, Assaf E. Partial oxidation of methane on NiO-MgO-ZrO₂ catalysts. Fuel, 2012, 97: 630–637

[22] Asencios Y, Assaf E. Combination of dry reforming and partial oxidation of methane on NiO-MgO-ZrO₂ catalyst: Effect of nickel content. Fuel Processing Technology, 2013, 106: 247–252

[23] Trimm D. Catalysts for the control of coking during steam reforming. Catalysis Today, 1999, 49(1-3): 3–10

Acknowledgements

The authors would like to thank National Center of Excellence for Petroleum, Petrochemicals, and Advanced Materials (PPAM), Chulalongkorn University for the financial support.

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2014 Higher Education Press and Springer-Verlag Berlin Heidelberg