由于还原剂甲烷价廉易得,甲烷选择性催化还原NOx(简称CH4-SCR)被认为是最有潜力替代NH3-SCR的催化还原技术。现有的CH4-SCR催化剂中,分子筛类催化剂因催化活性高而被广泛研究,但由于其水热稳定性不好,使得非分子筛负载的催化剂成为近年来的研究热点,其中主要包括固体超强酸和氧化物两大类。综述了这两类催化体系在催化活性、反应机理及掺杂改性等方面的研究现状,比较了各种催化剂的优缺点,并对CH4-SCR的发展前景进行了展望。
Selective catalytic reduction of NO with methane(CH4-SCR) has been deemed as a promising method to replace NH3-SCR because methane is low cost and easily obtained.Zeolite based catalysts have been widely researched because of their high catalytic activity.However,the hydrothermal stability of these catalysts is unsatisfied,which makes the none-zeolite based catalyst received considerable attention recently.In this paper,advances in supported none-zeolite catalysts for CH4-SCR are reviewed,especially focused on the catalytic activity,reaction mechanism and the promotion effect of the two types of catalysts based respectively on solid super acid and metal oxides.With the comparison of the properties of these catalysts,the application and further research direction on CH4-SCR are proposed.