铈基催化剂用于NH3选择性催化还原NOx的研究进展

源自固定源(如燃煤电厂烟气)和移动源(如机动车尾气)排放的氮氧化物(NO_x)造成了严重的大气污染,对其进行减排控制已迫在眉睫. 研究表明, 氨选择性催化还原(NH₃-SCR)技术是消除NO_x的最有效手段之一.铈基催化剂因其良好的氧化还原性能、适当的表面酸性、较高的储/释氧容量以及丰富的资源储备而被广泛用于NH₃-SCR反应. 探讨铈基组分在该反应中发挥的具体作用, 有助于了解相关催化过程的本质, 为现有催化剂的优化和新型催化剂的设计提供科学参考. 基于CeO₂在NH₃-SCR催化剂中扮演的不同角色, 本文从CeO₂作为载体、铈基复合氧化物、表面负载组分(助剂和活性组分)以及特殊结构的铈基催化剂等方面系统地介绍了近年来铈基催化剂在NH₃-SCR反应中的最新研究进展, 并对该领域未来可能的发展方向进行了展望.

Research Progress of Ceria-Based Catalysts in the Selective Catalytic Reduction of NOx by NH3

Nitrogen oxides (NO_x), which are emitted from stationary sources (such as coal-fired power plant flue gases) and mobile sources (such as motor vehicle exhausts), cause serious atmospheric pollution. As a result, it is very important to control the emissions of NO_x. Some studies have suggested that NH₃-selective catalytic reduction (NH₃-SCR) of NO_x is one of the best techniques for this purpose. Ceria-based catalysts are widely used in the NH₃-SCR reaction because of their good redox ability, suitable surface acidity, high oxygen storage or release capacity, and rich resource reserves. Investigating the role of ceria component in this reaction is important to understand the nature of the related catalytic process, and provides a valuable scientific reference for the optimization of existing catalysts and the design of novel catalysts. Based on the different roles of ceria in NH₃-SCR catalysts, we have performed a systematic review of the latest research progress of ceria-based catalysts in the NH₃-SCR reaction for the following aspects: CeO₂ used as supports, ceria-based mixed oxides, surface loading components (additives and active species), and ceria-based catalysts with special structures. Finally, we discuss the future directions of this field.