H2O对不同状态Pd催化剂上低浓度CO催化氧化性能的影响  

Role of H2O in Low Concentration CO Oxidation on Pd Catalysts with Different States

作　　者：吴彦町 张艳慧[1] 王丽[1] 郭杨龙[1] 詹望成[1] 郭耘[1] Wu Yanding;Zhang Yanhui;Wang Li;Guo Yanglong;Zhan Wangcheng;Guo Yun(Key Laboratory for Advanced Materials（Ministry of Education）,Research Institute of Industrial Catalysis,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学工业催化研究所结构可控先进材料教育部重点实验室

出　　处：《稀有金属》2018年第10期1068-1076,共9页Chinese Journal of Rare Metals

基　　金：国家重点基础研究发展计划项目(2016YFC0204300,2013CB933201);国家自然科学基金项目(21571061);上海市教育委员会曙光计划项目(12SG29)资助

摘　　要：采用不同的Pd前驱体，通过浸渍法制备了系列Al2O3负载Pd催化剂，研究表明：Pd的化学状态、卤素离子的引入等不仅可直接影响催化剂的氧化活性，还可影响气氛中H2O的作用。当Pd以氧化态存在时，以Pd（N03）2的HBr溶液为前驱体所制备得到的BrC催化剂具有最高的反应活性，而以PdCl2的HCl溶液为前驱体所得C1C催化剂的活性最低；经H2还原后，催化剂的活性均有显著的提高，其中以Pd（N03）2为前驱体所得CH催化剂表现出最高的CO氧化活性，另外两种催化剂活性相差不大。同时对于还原态催化剂，气氛中的H2O可抑制CH表面CO的吸附，并有利于02的吸附和活化，从而显著提高了CO的氧化活性；但c1和BT引人后，H2O的存在对CO吸附和活性影响不明显。当Pd以氧化态形式存在时，H2O的引入可促进BrC和C催化剂上的c0氧化，其中BrC催化剂上的促进作用最为明显，但却抑制了以PdCl2的HCI溶液为前驱体所得C1C催化剂上的CO氧化。Pd/Al2O3 catalysts were prepared by impregnation method using different precursors of Pd, the activities of CO oxidation and the roles of H2O in the reaction were investigated. The results showed the chemical states of Pd and the exit of halogen ions （ Cl/ Br） could directly affect the activities of CO oxidation and the role of H2O. For the Pd with high chemical valence, BrC catalyst pre-pared by using HBr solution of Pd（NO3）2 as precursor showed the highest activity for CO oxidation. While CIC catalyst prepared by using HCl solution of PdCl2 as precursor showed the lowest activity. After the reduction by H2 , the activities of catalysts were promoted significantly. Among them, CH catalyst prepared by using Pd（ NO3） 2 solution as precursor behaved the highest activity. The activity of other catalysts showed no difference. Meanwhile, the presence of H2O could block CO adsorption on the surface of CH catalyst and en- hance the adsorption and activation of O2, which could accelerate CO oxidation significantly. However, the presence of Cl/Br did not bring observable effects on the CO adsorption and oxidation. For the Pd with high chemical valence, H2O in the feed gas could promote CO oxidation on BrC and C catalyst. Among them, BrC showed the highest promotion. But block the CO oxidation on the ClC catalyst prepared by using HCl solution of PdCl2 as precursor.

关 键 词：CO 催化氧化 PD催化剂 水的影响 

分 类 号：TQ426[化学工程]