镨物种的掺杂量对Co_(0.1)Ce_(0.9-y)Pr_yO_x水蒸气重整乙醇反应催化性能的影响

Effect of Different Doping Amounts of Praseodymium Species on Activity of Co_(0.1)Ce_(0.9-y)Pr_yO_x Catalysts for Catalytic Steam Reforming of Ethanol

采用XRD,TPR,DSC和TG等方法对共沉淀法制备的Pr物种掺杂Co0.1Ce0.9-yPryOx催化剂的晶相结构、还原性能及反应后催化剂的热性能等进行了表征,并以水蒸气重整乙醇为探针反应考察了催化剂的活性、选择性和稳定性。结果表明:随着镨物种含量的增加,镨离子取代铈离子数量增多,引起晶格畸变,氧空位增多,并有利于钴物种的分散和还原,引导体相氧的溢出和传递。在水蒸气重整乙醇反应中,催化活性、H2的选择性随镨物种含量的增加而提高,而CO和CH4的选择性降低,Co0.1Ce0.70Pr0.2Ox样品在反应50 h后活性和H2的选择性仅下降4.6%和7.9%。

The effect of different praseodymium loadings of the Co0.1Ce0.9-yPryOx catalysts on the crystalline phase,reducibility,post-reaction thermal performance,and catalytic steam reforming of ethanol were studied by various experimental techniques（e.g.,XRD,CO-TPR,DSC-TG and micro-reactor test）.The catalyst samples were prepared by the co-precipitation method.The results showed that doping praseodymium ions could substitute cerium ions,and the substituting amounts of praseodymium ions increased with praseodymia loadings,resulting in the distortion of CeO2 crystal lattice and the increase of oxygen vacancies.This promoted the cobalt species dispersion and reducibility,and the overflow and migration of the body oxygen of CeO2 crystal.The catalytic activity and H2 selectivity of catalytic steam reforming of ethanol increased with the increase of praseodymium species loadings.The catalytic activity and H2 selectivity of Co0.1Ce0.70Pr0.2Ox sample declined by only 4.6% and 7.9% respectively after reaction for 50 h.