Modification Of Ni-Co Bimetallic Catalysts For Carbon Dioxide Reforming Of Methane

Ni-based catalyst is the best catalyst for carbon dioxide reforming of methane, the development and research of the catalysts with high activity and super anti-coking properties is the direction of the catalyst modified. The research is divided into three areas to study about methane dry reforming. First, a series of catalysts with different Ni loadings were prepared by the citric acid complexing method, the Ni loadings were5wt%、10wt%、15wt%、20wt%、25wt%、30wt%. Then these catalysts were characterized by XRD, H2-TPR, BET and other physical characterizations including the catalytic activity test. The results showed that15wt%is the best Ni loading for the Ni/Al2O3catalysts. This Ni-based catalyst is placed at750℃, atmospheric pressure, airspeed GHSV=24000ml· gcat-1·h-1to catalyze carbon dioxide reforming of methane. Conversion rate of methane rises up to84.3%, conversion rate of carbon dioxide rises up to84.8%. The highest selectivity for CO is94.4%. As the reaction was proceeding, the conversions of reactants and the selectivity of the product were showing a declining trend. Second, bimetallic catalysts with different mass fraction ratio NixCo1-x/Al2O3were prepared according to a preferred support amount of single metal catalysts. The catalysts were characterized by XRD, H2-TPR, BET and other physical characterization including the catalytic activity test. The results showed that when x=0.7,the Ni-Co bimetallic catalysts showed a good catalytic effect in the process of carbon dioxide reforming of methane:Conversion rate of methane rises up to92.3%, conversion rate of carbon dioxide rises up to91.6%. The highest selectivity for CO is95.3%; Third, this subject studied the impact of additives on the properties of the catalysts. Series of Ni-Co bimetallic catalysts added alkali promoters (K),alkaline earth metal additives (Sr) and rare earth elements (La, Ce) respectively were prepared. Studies have shown that different additives leave different influence on the catalysts for methane dry reforming. Rare earth additives Ce have the most obvious impact on the chemical properties of methane dry reforming catalysts: The Ni-Co bimetallic catalysts added Ce showed the highest methane conversion rate at94.7%, Carbon dioxide conversion rate of up to94.5%, the highest selectivity for CO is98.4%.