表面覆盖SiO_2用于提高Pt-Pd/CeO_2-ZrO_2-Al_2O_3商用柴油机氧化型催化剂的抗硫性（英文）  

Enhanced Sulfur Resistance of Pt-Pd/CeO_2-ZrO_2-Al_2O_3 Commercial Diesel Oxidation Catalyst by SiO_2 Surface Cladding

作　　者：杨铮铮[1] 杨怡[2] 赵明[2] 龚茂初[2] 陈耀强[1,2] 

机构地区：[1]四川大学建筑与环境学院,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,成都610064

出　　处：《物理化学学报》2014年第6期1187-1193,共7页Acta Physico-Chimica Sinica

基　　金：supported by the National Natural Science Foundation of China(21173153);National High-Tech Research and Development Program of China(863)(2013AA065304);Major Research Program of Science and Technology Department of Sichuan Province,China(2011GZ0035,2012FZ0008)~~

摘　　要：向Pt-Pd/CeO2-ZrO2-Al2O3(Pt-Pd/CZA)商用柴油机氧化型催化剂(DOC)中加入多孔SiO2以提高其抗硫性.使用多层涂覆法在Pt-Pd/CZA催化剂表面覆盖一层多孔SiO2,从而制得SiO2/Pt-Pd/CeO2-ZrO2-Al2O3(SiO2/Pt-Pd/CZA)抗硫DOC.并使用扫描电子显微镜(SEM),H2程序升温还原(H2-TPR),氮气吸脱附,X射线能谱(EDX)和热重分析(TGA)等对其进行表征.SEM结果显示,SiO2层以多孔形式均匀覆盖在催化剂表面.氮气吸脱附结果表明,所添加的SiO2的织构性质与Pt-Pd/CZA催化剂的织构性质相似,因而表面覆盖的SiO2并未明显改变Pt-Pd/CZA催化剂的比表面积和孔结构.H2-TPR结果证实表面覆盖的SiO2不影响Pt-Pd/CZA催化剂的还原性能.EDX和TGA结果说明表面覆盖SiO2可以抑制硫物种在催化剂表面的形成及累积.最终,本文所制备的SiO2/Pt-Pd/CZA催化剂在保持Pt-Pd/CZA商用DOC的高活性及耐久性的同时有效提高了其抗硫性.In this work, porous SiO2 was added to the Pt-Pd/CeO2-ZrO2-Al2O3 （Pt-Pd/CZA） commercial diesel oxidation catalyst （DOC） to improve its sulfur resistibility. The SiO2/Pt-Pd/CeO2-ZrO2-Al2O3 （SiO2/Pt-Pd/CZA） catalyst was prepared by surface coating porous SiO2 onto the Pt-Pd/CZA monolithic commercial DOC using a multilayer coating method. The as-prepared catalysts were characterized by scanning electron microscopy （SEM）, H2 temperature-programmed reduction （H2-TPR）, nitrogen adsorption-desorption, energy-dispersive X-ray （EDX） spectroscopy, and thermogravimetric analysis （TGA）. SEM images show that the SiO2 layer is porous and uniformly covers the surface of the catalyst. Nitrogen adsorption-desorption isotherm results imply that the texture properties of the as-added SiO2 are similar to those of the Pt-Pd/CZA catalyst, and hence the specific surface area and pore structure of the Pt-Pd/CZA catalyst do not obviously change upon cladding with SiO2. The H2-TPR results imply that the reduction property of the Pt-Pd/CZA catalyst is not obviously affected by surface cladding with SiO2. EDX spectroscopy and TGA results demonstrate that the formation and accumulation of sulfur-contained species on the Pt-Pd/CZA catalyst are suppressed by the SiO2 surface coating. Final y, the as-prepared SiO2/Pt-Pd/CZA catalyst efficiently retained its high catalytic performance and improved＆amp;nbsp;the sulfur resistance of the Pt-Pd/CZA commercial DOC.

关 键 词：柴油机氧化型催化剂 抗硫性 整体式催化剂 多层涂覆 机动车尾气 

分 类 号：TE624.9[石油与天然气工程—油气加工工程]