规则孔结构CeO_(2)设计和汽油车颗粒物氧化催化剂Rh/CeO_(2)的制备及性能研究  

Design of Regular Pore Structure CeO_(2)and Study on the Preparation and Performance of Rh/CeO_(2)Catalyst for Particulate Matter Oxidation of Gasoline Vehicle

作　　者：贾丰瑞 焦毅 刘志敏 姚鹏 王健礼[1] 陈耀强[1] 李云 JIA Fengrui;JIAO Yi;LIU Zhimin;YAO Peng;WANG Jianli;CHEN Yaoqiang;LI Yun(College of Chemistry,Sichuan University,Chengdu 610064,China;Institute of New Energy and Low-carbon Technology,Sichuan University,Chengdu 610064,China;Sinocat Environmental Technology Co.,Ltd.,Chengdu 610041,China)

机构地区：[1]四川大学化学学院,成都610064 [2]四川大学新能源与低碳技术研究院,成都610064 [3]中自环保科技股份有限公司,成都610041

出　　处：《材料导报》2023年第15期23-28,共6页Materials Reports

基　　金：国家自然科学基金(21902110);移动源污染排放控制技术国家工程实验室开放基金(NELMS2018A09)。

摘　　要：汽油车排放的颗粒物粒径小,数量大,不易沉积,对人体及环境危害大。在其尾气排气管中安装颗粒物捕集器(Gasoline particulate filter,GPF)是减少颗粒物排放最有效的手段;需要在GPF表面涂覆催化剂以维持其高效的捕集能力和再生性能,核心是催化剂。然而,碳烟(颗粒物模型物)催化氧化是典型的“气-固-固”三相界面反应,催化剂与碳烟的接触效率以及对气相氧的活化能力是关键。本工作以共聚物微球为模板制备了具有40 nm和80 nm孔径且贯穿孔结构的CeO_(2),并采用浸渍法制备Rh/CeO_(2)催化剂;系统地研究了孔径对催化剂-碳烟接触效率及Rh负载对气相氧活化能力的影响,从而探究其对碳烟氧化活性的影响。实验结果表明,通过共聚物微球模板法合成的CeO_(2)的催化活性优于商业化的CeO_(2),且孔径越大活性越好;结合表征结果说明本工作合成的80 nm贯穿孔结构CeO_(2)具有最大的储氧量且气相氧的活化能力最好;Rh负载CeO_(2)后,催化剂活性明显提高。Due to the small particle size,large amount and the difficulty of the deposit of particulate matters emitted from gasoline vehicles,it is harmful to human health and the environment.Installing the gasoline particulate filter(GPF)in the exhaust pipe is the most effective way to reduce particulate emissions.GPF requires a catalyst coated on its surface to maintain its high efficiency of capture and regeneration,in which the catalyst is key.However,the catalytic oxidation of soot particles is a typical gas-solid-solid three-phase interfacial reaction,and the key factors affec-ting the activity are the contact efficiency between the catalyst and soot and the gas-phase oxygen activation ability of the catalyst.In this work,CeO_(2)with 40 nm and 80 nm connected pore structures were prepared by using poly(acrylonitrile co styrene)copolymer microspheres as templates,Rh/CeO_(2)catalysts were prepared by using an impregnated method.The influences of pore size on the contact efficiency of catalyst-soot particles and the gas phase oxygen activation capacity of Rh introduction were systematically studied,so as to explore its influence on the oxidation activity of soot.The results of soot oxidation experiments show that the catalytic activity of CeO_(2)synthesized by template method is better than that of commercial CeO_(2),and the larger the pore size is,the better the activity is.Combined with the characterization results,the CeO_(2)with 80 nm connected pore structures has the optimal pore size,oxygen storage and oxygen mobility,and the corresponding Rh/CeO_(2)catalyst shows the better soot oxidation activity.

关 键 词：贵金属 二氧化铈 碳烟燃烧 大孔材料 颗粒物捕集器 

分 类 号：X513[环境科学与工程—环境工程] O643.322[理学—物理化学]