Pd呈特定分布的Pd/Al_2O_3催化剂的制备及其表面性能  

Preparation and Surface Charaeteristies of Pd-Al_2O_3 Catalysts with Special Distribution of Pd

作　　者：过中儒[1] 史鸿鑫[1] 徐慧珍[1] 

机构地区：[1]浙江工学院化工系,杭州310014

出　　处：《石油化工》1993年第6期358-363,共6页Petrochemical Technology

基　　金：国家自然科学基金

摘　　要：浸渍液的浓度、酸度和浸渍时间可影响H_2PdCl_4浸入Al_2O_3的深度。采用不同的竞争吸附剂和浸渍条件制得了Pd呈特殊分布的Pd/Al_2O_3催化剂。用光学照相法宏观地表征了Pd在Al_2O_3上的分布,用电子探针技术微观地表征了Pd的这种分布。Pd/Al_2O_3催化剂的表面特性和Pd的分布形式有关。TPR试验表明,Pd呈特定分布的 Pd/Al_2O_3催化剂的T_m值具有如下次序:蛋壳型>蛋白型>均匀型>蛋黄型。催化剂的H_2-O_2反应活性具有类似的次序。用TEM法测定的Pd/Al_2O_3催化剂的Pd粒度次序为:均匀型<蛋壳型<蛋白型<蛋黄型。The depth of impregnation of H_2PdCl_4 into Al_2O_3 can be affected by the con- centration, acidity of impregnation solution and impregnation time. Pd-Al_2O_3 cata- lysts with special distribution of Pd can be prepared by using different competitive adsorbates and under appropriate impregnation conditions. The distribution of Pd on Al_2O_3 section was observed macroscopically with photography and microscopi- cally with EPMA methods. The surface characteristics of Pd-Al_2O_3 catalysts are related to the type of distribution of Pd in Al_2O_3. TPR tests show that T_m values of Pd-Al_2O_3 catalysts with special Pd distribution types have the order of eggshell>eggwhite>uniformity >eggyolk. The catalytic activity of Pd-Al_2O_3 catalysts for H_2-O_2 reactoin has si milar order as above. TEM determination indicates that the Pd particlesize or- der of Pd-Al_2O_3 catalysts is: uniformity<eggshell<eggwhite<eggyolk type.

关 键 词：催化剂 表面性能 钯催化剂 

分 类 号：TQ426.94[化学工程]