添加Ni对Cu基催化剂乙炔选择性加氢性能的影响

Effects of Ni addition into Cu-based catalysts on selective hydrogenation of acetylene

采用等体积浸渍法制备了Cu/Al_2O_3及Cu-Ni/Al_2O_3催化剂,将其应用于乙炔选择性加氢反应。结果表明,与Cu/Al_2O_3催化剂相比,Cu-Ni/Al_2O_3催化剂的加氢活性及乙烯选择性(当反应出口尾气中乙炔物质的量分数减少到0.003%时)明显提高。通过对Cu与Ni的浸渍顺序考察发现,先浸渍Ni制得的Cu-Ni/Al_2O_3催化剂活性有所下降,但乙烯选择性提高;通过对Ni含量的考察发现,当Ni质量分数为2%时,催化剂性能最佳。

Cu/Al2O3 and Cu-Ni/Al2O3 catalysts were prepared by incipient wetness impregnation method and applied in selective hydrogenation of acetylene. The results showed that compared with Cu/Al2O3 cat- alyst, the hydrogenation activity of Cu-Ni/Al2O3 catalyst and the selectivity to ethylene were significantly improved when the molar fraction of acetylene in the reaction effluent was reduced to 0. 003%. The impregnation order of Cu and Ni as well as Ni contents was investigated. It was found that the activity of Cu-Ni/Al2O3 catalyst prepared by stepped impregnation method （Ni first impregnated） was decreased, but the selectivity to ethylene was improved. When Ni mass fraction was 2% , the catalyst exhibited the best performance.