壁载氨氧化催化剂X/TiO_2(X=Pt、Pd、Au)制备与反应机理  

Preparation of wall-loaded X/TiO_2(X=Pt,Pd,Au) catalysts for ammonia oxidation process and the reaction mechanism

作　　者：邱伟 陶阳 蒋炜[1] 梁斌[1] QIU Wei;TAO Yang;JIANG Wei;LIANG Bin(School of Chemical Engineering,Sichuan University,Chengdu 610065,Sichuan,China)

机构地区：[1]四川大学化学工程学院,四川成都610065

出　　处：《化工进展》2017年第11期4093-4098,共6页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金项目(21476146;21176157)

摘　　要：催化剂壁载化是在微通道反应器内负载催化剂的有效方法,适用于氨氧化过程这一强放热气固反应体系,但不同的催化剂壁载化后其催化性能还有待研究。本研究通过将Pt、Pd、Au 3种贵金属通过光催化沉积方法负载于TiO_2纳米管上并组装入微通道反应器内,考察了其催化氨氧化过程性能,并通过密度泛函方法解释了其性能差异。结果证实,TiO_2载体对催化过程无明显影响,3种催化剂催化活性顺序为Pt/TiO_2>Pd/TiO_2>Au/TiO_2,其中Pt/TiO_2氨转化率在280℃下即可达100%,NO选择性380℃即达99%。TPD检测及模拟证实,NH3及O2在催化剂表面吸附能大小顺序为Pt>Pd>Au,与催化活性顺序一致。Wall-loading is an effective method to load catalyst inside microchannel reactor,which canbe applied to highly exothermic gas-solid reactions such as ammonia oxidation.However,the catalyticperformance of different wall-loaded catalysts needs to be further studied.In this research,three metalsPt,Pd,and Au,were loaded on TiO2nanotubes by photocatalytic deposition,and then assembled ina microchannel reactor to evaluate their catalytic performance for ammonia oxidation.The performancedifference was discussed based on the density functional method.Results confirmed that no significantcatalytic activity of bare TiO2nanotubes had been observed.The determined activity sequence of threecatalysts is Pt/TiO2>Pd/TiO2>Au/TiO2.Ammonia conversion by Pt/TiO2reached100%at280℃,andNO selectivity was up to99%at380℃.TPD analysis and simulation confirmed the adsorption energyof NH3and O2on the catalyst surface was in the order of Pt>Pd>Au,which was consistent with thatof their catalytic activity.

关 键 词：催化剂 化学反应 数值模拟 微反应器 吸附 

分 类 号：TQ11[化学工程—无机化工]