Mn基低温SCR催化剂的抗H_2O、抗SO_2研究进展

Review on manganese based catalysts resistant to H_2O and SO_2 for SCR reduction at low temperature

Mn基催化剂因具备良好的催化性能而广泛应用于低温NH_3-SCR脱硝研究领域,然而烟气中存在的H_2O、SO_2会导致催化剂较严重地失活,故研究低温Mn基催化剂的抗H_2O、抗SO_2性能十分必要。本文主要阐释了H_2O、SO_2的作用机理,详细归纳了抗H_2O、抗SO_2效果较好的Fe、Ce、Sm、Sn等金属掺杂型、Mn-Ce/TiO_2等常规载体及Mn/Fe-Ti等复合载体构成的负载型、Fe_2O_3@MnO_x@CNTs等核壳结构型和Mn_xCo_(3-x)O_4纳米笼等规则结构型组成的特殊结构型Mn基催化剂,简要总结了各类催化剂的现阶段研究进展和局限,并提出各类型催化剂的未来可能研究方向为优化金属掺杂催化剂的制备方法或添加新型有效助剂,保证高抗性前提下进一步降低载体型催化剂的工作区间以及批量化制备特殊结构型催化剂。

Manganese-based catalysts are widely used in NH_3-SCR reduction owing to their excellent catalytic performance at low temperature. However,H_2O and SO_2 will cause server catalyst deactivation,thus it is necessary to develop the catalysts resistant to H_2O and SO_2. This study mainly summarizes the deactivation mechanism of H_2O and SO_2,and reviews some compound catalysts such as Mn-Fe,Mn-Ce,Mn-Sm,Mn-Sn,and supported catalysts with both conventional carrier like TiO_2 and Al_2O_3 and metal modifying carrier like Fe-Ti and Ce-Zr. The catalysts with special construction for instance MnO_2@NiCo_2O_4 core-shell structure and Mn_xCo_（3-x）O_4 regular nanocage-shape structure are also discussed. The superiority and inferiority of each kind catalyst are introduced and the possible research directions in future are proposed as to optimize the preparation method of the metal doped catalyst or add new effective additives to reduce the working temperature of the supported catalyst while ensure high resistance to H_2O and SO_2,and to explore the large-scale preparation method for special structured catalysts.