Study On Ni Based Catalyst With Different Support In Partial Oxidation Of Methane To Synthesis Gas

Partial oxidation of methane (POM) to synthesis gas has caused much attention in the research field, since it has advantages such as high efficiency, mild exothermicity, high selectivity of product and affords suiltable product to synthesis methanal and for Fischer-Tropsch process. Many researchers have been working at developing an active and stable Ni catalyst to solve the problem of carbon deposition and metal sintering.In this paper, XRD,BET,H2-chemsorption,TPR,TG-DTA,Raman and catalytic evaluation were used to investigate the influence of different support(CeO₂-ZrO₂,α-Al₂O₃ and CeO₂-ZrO₂/Al₂O₃) and preparation techniques of CeO₂-ZrO₂/Al₂O₃ support on catalytic activity, carbon resistant activity and metal sintering. Meanwhile, the optimal Ni loading and reaction mechanism at our experiment conditions were also studied.The results show that 10% were the optimal loading, which is determined by amount of Ni and metal dispersion. Different supports cause different character and catalytic performance. Ni/CeO₂-ZrO₂/Al₂O₃ has lower initiative activity and need a longer activation process than Ni/α-Al₂O₃ and Ni/CeO₂-ZrO₂. But it is more stable and resistant to carbon due to strong metal-support interaction. Raman spectra show that after 24h reaction, carbon deposits observed is inorganic carbon and belongs to graphite carbon and imperfect graphite. In the experiment condition, the reaction follows combustion-reforming mechanism.Catalytic performance of Ni/CeO₂-ZrO₂/Al₂O₃ catalysts differed from support preparation techniques. During 24h reaction, mechanical mixing sample maintained good catalytic stability and prohibited metal sintering and carbon, while atomic mixing sample suffered serious carbon deposition and Ni sintering. Characterization results indicate that Ni-Al strong interaction makes mechanical mixing sample resist to carbon and sintering, furthermore improves the catalytic stability. Moreover, there is interaction between CeO₂-ZrO₂ and Al₂O₃ which has some influence on Ni-support interaction.