Study Of The Support Influence On Ni Based Catalyst In Partial Oxidation Methane

Partial oxidation of methane (POM) to synthesis gas, which has the advantages of mild exothermic reaction, higher efficiency, and afford suitable product to synthesize methanol and for Fischer-Tropsch process has caused attention of research field. Many researchers have been working at developing an activity, stable and long life Ni catalyst to solve the problem of carbon deposition and metal sintering.In this paper, XRD, low temperature N₂ adsorption, TPR, TG-DTA and catalytic evaluation were used to investigate the influence of the surface area, pore size and pore volume of the supportα-Al₂O₃, promoter of CeO₂ and CeO₂-ZrO₂ on catalytic activity, carbon resistant activity and metal sintering. Meanwhile, the optimal of CeO₂-ZrO₂ loading was also studied.The results show the support ofα-Al₂O₃ can improve catalytic activity, support character have an important effect to catalytic performance of catalysts, the high surface area redound to metal dispersed and increase activity sites, so can increase the catalytic activity; big pore size and pore volume make the reactant adsorption quickly and moving the reaction heat in times to avoid catalysts sintering .The key is setting up balance relation of the surface area, pore size and pore volume.15%CeO₂-ZrO₂/Ni/Al₂O₃ catalytic activity and catalytic stability is best. Because the strong metal-CeO₂-ZrO₂ interaction can restrain carbon and the lattice oxygen of CeO₂-ZrO₂ can remove the deposition carbon. 15%CeO₂/Ni/Al₂O₃ catalytic activity is the worst in the catalysis of 15%CeO₂-ZrO₂/Ni/Al₂O₃, 15%CeO₂/Ni/Al₂O₃ and Ni/Al₂O₃. This is due to instability of CeO₂ in high temperature. The results also show that 15wt.% is the optimal loading, which was determined by amount of CeO₂-ZrO₂ and metal dispersion.