Research progress in the SO2 resistance of the catalysts for selective catalytic reduction of NOx

The selective catalytic reduction (SCR) of NOx with NH3 has been proven to be an efficient technology for NOx conversion to N-2. However, the catalysts used for SCR usually suffer from the problem of sulfur poisoning which seriously limits their practical application. This review summarized sulfur poisoning mechanisms of various SCR deNO(x) catalysts and strategies to reduce deactivation caused by SO2 such as doping metals, controlling the structures and morphologies of the catalysts, and selecting appropriate supports. The methods and procedures of catalysts preparation and the reaction conditions also have effect on SO2-resistance of the catalysts. Several novel catalyst systems that exhibited good SO2 resistance are also introduced. This paper could provide guidance for the development of highly efficient sulfur-tolerant deNOx catalysts. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.