ZnO添加量对Pd/Zr_(0.5)Al_(0.5)O_(1.75)催化剂净化稀燃天然气汽车尾气性能的影响  

Effects of ZnO content on the performance of Pd/Zr_(0.5)Al_(0.5)O_(1.75) catalysts used in lean-burn natural gas vehicles

作　　者：王云[1,2] 尚鸿燕 徐海迪[2] 龚茂初[2] 陈耀强[1,2] 

机构地区：[1]四川大学化学工程学院,四川成都610064 [2]四川大学化学学院绿色化学与技术教育部重点实验室,四川成都610064

出　　处：《催化学报》2014年第7期1157-1165,共9页

基　　金：国家自然科学基金(21173153)~~

摘　　要：以掺杂不同含量ZnO的Zr0.5Al0.5O1.75为载体,制备了系列1.5%Pd催化剂.在模拟稀燃天然气汽车尾气条件下,测试了催化剂的活性和抗水性,并用N2吸附-脱附、X射线衍射、H2程序升温还原和X射线光电子能谱等手段对催化剂进行了系统表征.研究结果表明,ZnO的添加及添加量对催化剂的活性和抗H2O性有明显影响,其中以ZnO添加量为15%时制备的复合氧化物为载体的催化剂活性最佳.当模拟尾气中不含H2O时,该催化剂对甲烷的起燃温度(T50)和完全转化温度(T90)分别为278和314°C;在含H2O时,该催化剂的T50和T90分别为342和371°C.Mixed oxides obtained by adding varying amounts of ZnO into Zr0.5Al0.5O1.75 were used as supports to prepare 1.5% Pd catalysts. The catalyst activity and H2O tolerances of the catalysts were evaluated in a gas mixture simulating the exhaust of lean-burn natural gas-fueled vehicles. The catalysts were further characterized by N2 adsorption-desorption, X-ray diffraction, H2 temperature pro-grammed reduction and X-ray photoelectron spectroscopy. The catalytic activity was greatly influenced by ZnO contents in Zr0.5Al0.5O1.75 support. The catalyst containing 15% ZnO exhibited a light-off temperature and complete conversion temperature for CH4 in the absence of H2O of 278 and 314 ℃, respectively; while these same values in the presence of H2O were 342 and 371 ℃, respectively. These results indicate that this combination of materials offers excellent catalytic activity at low temperature and also exhibits significant H2O tolerance.

关 键 词：锆 铝 锌 钯 复合氧化物 稀燃 天然气汽车 水抑制 

分 类 号：O643.36[理学—物理化学]