Ni-Co bimetallic catalyst for CH₄ reforming with CO₂

Abstract

A co-precipitation method was employed to prepare Ni/Al₂O₃-ZrO₂, Co/Al₂O₃-ZrO₂ and Ni-Co/Al₂O₃-ZrO₂ catalysts. Their properties were characterized by N₂ adsorption (BET), thermogravimetric analysis (TGA), temperature-programmed reduction (TPR), temperature-programmed desorption (CO₂-TPD), and temperature-programmed surface reaction (CH₄-TPSR and CO₂-TPSR). Ni-Co/Al₂O₃-ZrO₂ bimetallic catalyst has good performance in the reduction of active components Ni, Co and CO₂ adsorption. Compared with mono-metallic catalyst, bimetallic catalyst could provide more active sites and CO₂ adsorption sites (C+ CO₂ = 2CO) for the methane-reforming reaction, and a more appropriate force formed between active components and composite support (SMSI) for the catalytic reaction. According to the CH₄-CO₂-TPSR, there were 80.9% and 81.5% higher CH₄ and CO₂ conversion over Ni-Co/Al₂O₃-ZrO₂ catalyst, and its better resistance to carbon deposition, less than 0.5% of coke after 4 h reaction, was found by TGA. The high activity and excellent anti-coking of the Ni-Co/Al₂O₃-ZrO₂ catalyst were closely related to the synergy between Ni and Co active metal, the strong metal-support interaction and the use of composite support.

Key words： Ni-Co bimetallic catalyst; composite support; CH₄ reforming with CO₂

Acknowledgments

This work was supported by the National Basic Research Program of China (2005CB221207), the National Natural Science Foundation of China (Grants Nos. 20846002, U0970134), and the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT0517), the Program for New Century Excellent Talents in University (No. NCET-05-0267), and the Ph.D. Programs Foundation for New Teacher (No.20091402120013) in Ministry of Education, China.

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