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柴油车尾气NO_x控制是目前大气污染控制领域的重要研究内容,对改善城市大气污染现状有着极其重要的作用。NH_3选择性催化还原NO_x(NH_3-SCR)是应用于该领域的主流技术之一。近年来,以具有菱沸石(chabazite,CHA)结构的分子筛为载体负载Cu制备的Cu-CHA(Cu-SSZ-13和Cu-SAPO-34)系列催化剂,因其优秀的NH_3-SCR活性和良好的水热稳定性,成为学者们关注的热点。本文首先从制备方法及反应条件对Cu-CHA催化性能的影响和NH_3-SCR反应机理这几个方面系统阐述Cu基菱沸石在柴油车尾气NO_x催化净化领域的研究进展;然后总结了负载其他过渡金属和稀土金属制备的M-CHA分子筛催化剂在NH_3-SCR反应中的应用,指出双活性中心菱沸石催化剂在NH_3-SCR领域表现出的优势;在此基础上对菱沸石NH_3-SCR催化剂的进一步改良做出展望。
NO_x control of diesel exhaust is an important research area in the field of air pollution control and plays an extremely important role in improving the status of urban air pollution. The selective catalytic reduction of NO_x (NH_3-SCR) by NH_3 is one of the mainstream technologies applied in this field. In recent years, a series of Cu-CHA (Cu-SSZ-13 and Cu-SAPO-34) catalysts supported on Cu supported on molecular sieves with chabazite (CHA) structure have been studied for their excellent NH 3 -SCR activity and good The hydrothermal stability has become a hot topic of scholars. In this paper, the research progress of Cu-chabazite in NO_x catalytic purification of diesel exhaust is systematically described from the influence of preparation method and reaction conditions on the catalytic performance of Cu-CHA and the reaction mechanism of NH_3-SCR. Then, The application of M-CHA molecular sieve catalyst prepared from metal and rare earth metal in NH 3-SCR reaction indicates the advantage of dual active center chabazite catalyst in the field of NH 3-SCR. On the basis of this, Improve to make a look.