N_2O的催化分解研究

Catalysts for Catalytic Decomposition of Nitrous Oxide

N2O是主要的温室气体之一,它在对流层中具有破坏臭氧的作用,因此,N2O的消除越来越引起人们的重视。N2O的直接催化分解是公认的消除N2O污染的最有前景的方法之一,具有操作简单、成本低、不需引入其他杂质、不产生二次污染等特点。本文综述了近年来在N2O催化分解领域广受关注的几类催化剂的最新研究进展,包括金属氧化物催化剂、负载型贵金属催化剂和分子筛催化剂体系,概括了这些催化剂的优点和缺点,介绍了固体催化剂表面N2O催化分解的反应动力学、分子模拟及反应机理。从工业应用角度出发综述了工业生产过程中可能对催化活性造成影响的NOx、O2、H2O和SO2等其他气体对催化剂活性、寿命和稳定性的影响。最后指出了N2O催化分解理论研究及催化剂体系存在的一些问题,并在此基础上对N2O催化分解体系的发展前景进行了展望。

Nitrous oxide（N2O）originating from industrial and automotive emissions is accepted to be a major air pollutant. It contributes to the greenhouse effect and the depletion of stratospheric ozone. In recent years, elimination of N2O has attracted increasing attention for concerns from environment pollution. The necessity to reduce N2O emissions requires the development of catalytic technologies. Direct catalytic decomposition of N2O to N2 and O2 has been recognized as one of the most prospect methods for elimination pollution derived from N2O, since it does not require the addition of any reductant, without causing secondary pollution, and the process it concerned is simple and economical. This paper reviews the advance of several interesting catalysts that have been paid great attention in recent years, including metal oxides, noble metals and ion-exchanged zeolites catalyst systems. The advantages and disadvantages of the catalysts are also discussed in detail. This review also covers the research progress of reaction mechanism, molecular simulation and reaction kinetics on the surface of solid catalysts. Besides, the effects of moecular oxygen, water, sulfur dioxide and other species on the catalysts＇ activity, life and stability, are also included in this paper. The demerits exist both in these catalysts and theoretical research for the decomposition of N2O are pointed out. Finally, the trends in the catalyst system for direct catalytic decomposition of N2O are prospected.