Ce-Zr固溶体负载Ni制备方法对HI催化分解制氢的影响

INFLUENCE OF PREPARATION METHODS OF NI SUPPORED BY CERIA-ZIRCONIA ON HI CATALYTIC DECOMPOSITION FOR HYDROGEN PRODUCTION

分别采用浸渍法、溶胶凝胶法和共沉淀法,制备3种Ni负载量为5%的Ni/Ce_(0.8)Zr_(0.2)O_2,用于HI催化分解。相比HI均相分解,3种催化剂效果都很好。采用BET、XRD和TEM等手段对3种催化剂进行表征。ZrO_2掺杂入CeO_2晶格后,可改变氧化物的体相构成,有利于体相氧的迁移和扩散。Ni共同参与溶胶-凝胶过程时,Ni^(2+)也掺杂入CeO_2晶格,从而使Ni-doping-G的抗烧结性、热稳定性,金属利用效率和表面活性有很大提高。3种催化剂中,Ni-doping-G比表面积和孔容积最大,金属元素分散性最高,热稳定性最好,同时在实验中表现出良好的催化活性。

In this study, 5%Ni/Ce0.8Zr0.2O2 catalysts prepared by immersion method, sol-gel method and precipitation method, are tested for hydrogen iodide （Hi）decomposition. Compared with Hi homogeneous decomposition, three kinds of catalysts using each method all obtain good catalyzing effects. In this study, the three catalyst samples were characterized by XRD, TEM and EDS. The incorporation of zirconia into ceria lattice changes the bulk phase structure of ceria, and it＇ s beneficial to mobility of bulk phase oxygen. When Ni involved in the sol-gel process and Ni2＋ incorporated into ceria lattice, there are significant improvements in sintering resistance, thermal stabilities, and utilization of metal and surface activity for catalysts. Ni-doping-G sample shows the best specific surface area, pore volume, dispersion of metallic composition and thermal stabilities, etc. Hence, Ni-doping-G synthesized by citric-aided sol-gel method shows a good catalytic performance in experiments.