采用液态离子交换法制备了不同含量的Mn／ZSM-5型分子筛催化剂，并考察了上述催化剂的物理化学特性及其在NH3-SCR反应中的催化性能。理化分析结果表明：所制备催化剂在Mn含量≤9．2％时具有高度的分散性，分子筛表面团聚的氧化锰颗粒粒径小于4nm；锰元素主要富集于分子筛的浅层及表面。催化性能研究结果表明：Mn含量达到1．4％时，低温催化中心即达饱和，继续增加Mn含量对低温反应性能影响不大；反应温度超过300℃时，高温催化中心开始起作用；含量为3．1％的Mn／ZSM-5催化剂具有最宽的高活性反应温度窗口。
Mn/ZSM-5 zeolite catalysts with different manganese content were prepared using liquid ion-exchange method. The effects of manganese loading ratios on physical-chemical characterization and selective catalytic reduction of NOx with ammonia were investigated. The physical-chemical analysis showed that manganese species were finely dispersed on the ZSM-5 support with manganese content 〈9.2%, corresponding to the manganese oxide particle size 〈4 nm. Manganese mainly enriches in the surface of the ZSM-5 support. The study on the catalytic performance represents： at manganese loading 〈1.4%, the low-temperature catalytic center tended to saturate, and further increasing the manganese content had little influence on the low-temperature reaction; when the reaction temperature exceeds 300℃, high temperature catalytic center was activated. Among all of the catalyst tested, Mn/ZSM-5 catalysts loading of 3.1% exhibited the most efficient and widest temperature window.
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