机动车尾气脱硝催化剂Cu-SSZ-13的改性研究进展

Research progress on modification of Cu-SSZ-13 catalyst for denitration of automobile exhaust gas

Cu-SSZ-13催化剂具有优异的CHA骨架结构,在机动车尾气脱硝领域具有很好的应用前景,目前在欧洲已经实现商业应用。为解决尾气中硫氧化物和水热冲击对Cu-SSZ-13骨架和活性位点产生的损害问题,对其进行改性是目前的研究重点。本文归纳了近年来针对Cu-SSZ-13催化活性位点的研究进展以及水热老化、硫中毒导致其失活的机理研究成果;重点论述了针对Cu-SSZ-13催化活性和耐受性能提升的最新改性方法(包括创建新型纳米结构、构建中毒牺牲位点、金属掺杂改性等),以期为提升Cu-SSZ-13催化性能和抗中毒性能研究提供新思路;对Cu-SSZ-13改性技术的未来发展进行展望,提出通过特定金属掺杂和新颖制备方法来控制沸石内的离子种类可实现调控活性位点的创新思路。最后针对性讨论了催化剂改性过程中需要解决的关键问题。

Cu-SSZ-13 is an excellent deNO_(x) catalyst with CHA skeleton structure,and thus it possesses good application prospect in the field of vehicle exhaust deNO_(x) and has been applied commercially in Europe.However,the hydrothermal deactivation and sulfur poisoning of Cu-SSZ-13 will cause serious damage to the CHA skeleton structure and active sites of Cu-SSZ-13 and has limited its development.In order to solve these problems,the modification of Cu-SSZ-13 catalyst has become the focus of current research.The recent research progress on the active sites of Cu-SSZ-13 catalyst and the mechanism of its deactivation caused by hydrothermal aging and sulfur poisoning were summarized.Also,the latest modification methods aimed at improving the catalytic activity and tolerance of Cu-SSZ-13,such as creating new nanostructures,constructing poisoning sacrifice sites,metal doping modification,were discussed,which provides a new thought for enhancing the catalytic performance and anti-poisoning performance of Cu-SSZ-13.Furthermore,the future development of Cu-SSZ-13 modification technology was prospected with the innovative idea of regulation of the active site by specific metal doping and novel preparation methods to control the type of ions in the zeolite.Finally,the essential problems to be solved in catalyst modification were discussed.