糠醛液相脱羰用Pd/γ-Al_2O_3催化剂制备新工艺研究及活性评价

New Preparation Process of Pd/γ-Al_2O_3 Catalyst for Liquid Decarbonylation of Furfural and Its Catalytic Properties

采用浸渍沉淀法制备了糠醛液相脱羰用Pd/γ-Al2O3催化剂,讨论了浸渍初始液pH、加入载体后浸渍液pH、还原时pH、浸渍时间对催化剂活性的影响,确定了最佳的制备条件为:浸渍初始液pH=1;加入载体后浸渍液pH=7;还原时pH=8;浸渍时间=60 min。X射线衍射表征结果显示,催化剂中的钯以零价态存在,透射电镜分析结果显示在催化剂中钯粒子分散度较好,平均粒径约为15 nm。在糠醛液相脱羰反应中,该催化剂较常规浸渍法制备的Pd/γ-Al2O3催化剂具有更好的催化活性,在适宜条件下呋喃收率为87.4%。与其它方法比较,该催化剂制备工艺具有过程简单,适合工业化生产的优点。

Pd/γ-Al2O3 catalyst for liquid decarbonylation of furfural was prepared by impregnation-precipitation method for the first time.Effects of initial impregnation solution pH,pH value of impregnation solution after adding carrier,impregnation time on catalyst activities were investigated.The appropriate initial impregnation solution pH is 1,pH after adding carrier impregnation solution is 7,reduction pH is 8,impregnation time is 60 min.XRD studies showed that Pd was reduced to elementary valence state in the catalysts.TEM studies show that Pd particals are well dispersed and the average size of Pd particals is 15 nm.The catalyst prepared by this method is more active than those prepared by conventional methods in liquid decarbonylation of furfural reaction.The yield of furan is 84.7% at proper condition.Comparison with other methods of preparation,this preparation of process is simple and suitable for industrial production.