载体形貌调控Ni基催化剂甲烷干重整反应性能的研究OA北大核心CSTPCD

The methane dry reforming(DRM)reaction is of great significance for the co-conversion and utilization of greenhouse gases CO2 and CH4.However,this reaction faces the crucial problem of catalyst deactivation caused by carbon deposition.The influence of support morphologies on the reaction performance in DRM over Ni-based catalysts was investigated by preparing flower-shaped,granular and sheet-like MgO supported catalysts.The influence mechanisms were clarified by various characterizations such as XRD,SEM,H2-TPR,CO2-TPD and TG.The results show that under the temperature of 800 ℃ and space velocity of 54000 mL/(g·h),the average CO2 and CH4conversion rates of Ni-based catalysts supported on flower-shaped MgO reach 90.2％and 82.3％,respectively,with the average n(H2)/n(CO)of 0.93 after 50 h reaction.Compared with Ni-based catalysts supported on granular and sheet-like MgO,the Ni-based catalyst supported on flower-shaped MgO exhibits higher activity,stability and anti-carbon deposition ability.This is because the flower-shaped MgO has a higher specific surface area favorable for the dispersion of active metals,and there are more alkaline sites on the surface of flower-shaped MgO,which contribute to the adsorption and activation of CO2,enhance the anti-carbon deposition ability of catalysts and improve the activity and stability of DRM reaction.