Ce掺杂对Pd/γ-Al2O3催化燃烧甲苯性能的影响  

Effect of Ce doping on the performance of Pd/γ-Al2O3 catalytic combustion of toluene

作　　者：任思达[1] 梁文俊[1] 王昭艺 杜晓燕 李坚[1] 何洪[1] REN Si-da;LIANG Wen-jun;WANG Zhao-yi;DU Xiao-yan;LI Jian;HE Hong(Key Laboratory of Beijing on Regional Air Pollution Control, Beijing University of Technology, Beijing 100124, China)

机构地区：[1]北京工业大学区域大气复合污染防治北京市重点实验室

出　　处：《中国环境科学》2019年第7期2774-2780,共7页China Environmental Science

基　　金：国家重点研发计划(2016YFC0204300);北京市科学技术委员会科技计划资助项目(Z161100004516013)

摘　　要：过等体积浸渍法制备了单金属Pd/γ-Al2O3催化剂和双金属Pd-Ce/γ-Al2O3催化剂,考察掺杂CeO2对Pd/γ-Al2O3催化剂催化氧化甲苯性能的影响.并通过N2吸脱附、SEM、H2-TPR表征催化剂比表面积、表面形貌及氧化还原性能.结果发现,CeO2的掺杂一定程度上降低了Pd/γ-Al2O3催化剂的比表面积,但增加了10nm孔径的孔密度,且催化剂仍保持介孔结构,当添加4%CeO2时(质量分数,下同),催化剂比表面积降至165m2/g,孔道存在一定程度的堵塞,阻碍污染物和反应产物的扩散,降低催化剂催化性能.H2-TPR结果表明,Pd和Ce之间存在较强的协同作用,与PdO相邻的CeO2更容易打开Ce-O键,相较于单金属0.2%Pd/γ-Al2O3,掺杂了0.3%CeO2的催化剂具有更强的还原峰,表明CeO2的引入为催化剂提供了更多的表面氧空位,增强了催化剂的催化氧化能力,其T10和T90与单贵金属催化剂相比分别降低10和40℃.A single metal Pd/γ-Al2O3 catalyst and a bimetallic Pd-Ce/γ-Al2O3 catalyst were prepared by equal volume impregnation method to investigate the effect of CeO 2 doping on the catalytic oxidation of toluene.The specific surface area,surface morphology and redox properties of the catalyst were characterized with N 2 desorption,SEM and H2-TPR.It was found that the doping of CeO2 reduced the specific surface area of Pd/γ-Al2O3 catalyst to a certain extent,but increased the pore density of 10nm,and the catalyst still maintained the mesoporous structure.When 4%CeO 2 was added(mass fraction,the same below),the specific surface area of the catalyst was reduced to 165m^2/g,and there was a certain degree of clogging in the pores,which hindered the diffusion of pollutants and reaction products,and reduced the catalytic performance of the catalyst.The H2-TPR results showed that there is a strong synergistic effect between Pd and Ce.CeO 2 adjacent to PdO was more likely to open Ce-O bond,which was 0.3compared with single metal 0.2%Pd/γ-Al2O3 catalyst.The catalyst of%CeO2 had a stronger reduction peak,indicating that the introduction of CeO2 provided more surface oxygen vacancies for the catalyst and enhances the catalytic oxidation ability of the catalyst.in which the T 10 and T 90 were reduced by 10℃and 40℃respectively.

关 键 词：甲苯 催化氧化 CEO2 PD 协同作用 

分 类 号：X511[环境科学与工程—环境工程]