A series of silica supported transition metal phosphide catalysts were prepared through isovolumetric impregnationand heat treatment under N2 protection. Their catalytic performances were evaluated by ethanol yield and reaction kinetics of acetic acid hydrogenation. Results showed that both conversion of acetic acid and ethanol selectivity were gradually increased with reaction temperature increasing from 280℃ to 340℃. With P/Ni molar ratio for catalyst preparation was increased from 2:1 to 4:1, the obtained catalysts exhibited first increase and then decrease in activity and selectivity with optimal performance at P/Ni=3:1. The catalyst prepared by heat treatment at 250℃ had better catalytic performances than those at 200℃ and 300℃. The activity and ethanol selectivity of Ni2P/SiO2 catalysts were higher than that of Co2P/SiO2 catalysts. Catalysts using sodium hypophosphite as phosphorus supplement had better performance than those of potassium hypophosphite. Under temperature at 340℃, pressure at 2.0 MPa, molar ratio of hydrogen to acetic acid at 10:1, and WHSV at 0.4 h-1, acetic acid hydrogenation over Ni2P/SiO2 prepared in better conditions showed 100% conversion of acetic acid and 74.56% selectivity of ethanol. In addition, ethanol selectivity could be further improved by appropriate increase of reaction temperature.%通过等体积浸渍和N2气流中热处理过程制备了系列氧化硅负载过渡金属磷化物催化剂,经乙酸加氢制乙醇反应实验和动力学分析评价催化剂性能.研究结果表明,随着反应温度从280℃升高到340℃,乙酸转化率和乙醇选择性均逐渐提高.随着催化剂制备的P/Ni摩尔比从2:1增大到4:1,催化剂活性和乙醇选择性均先增大后减小,P/Ni摩尔比为3:1催化剂性能较佳.250℃热处理制备催化剂的催化性能优于200℃及300℃.Ni2P/SiO2催化剂活性和乙醇选择性均高于Co2P/SiO2催化剂.用次磷酸钠作为磷补充源制备催化剂的性能优于次磷酸钾.采用较佳条件下制备的Ni2P/SiO2催化剂,在温度340℃、压力2.0 MPa、氢酸进料量比10:1、质量空速0.4 h-1条件下进行乙酸加氢反应,乙酸转化率为100%,乙醇选择性达到74.56%,并且适当升高反应温度会进一步提高乙醇选择性.
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