复合载体对选择性催化还原催化剂低温脱硝性能的影响

采用浆液浸涂法在堇青石蜂窝陶瓷载体上涂覆Al2O_3-TiO_2-ZSM-5分子筛复合载体,并通过浸渍法负载活性组分Mn-Fe-Ce,制备了M/ATZ-CC选择性催化还原催化剂。考察了催化剂的低温脱硝活性和抗水性能,表征了催化剂的物性参数和氨-程序升温脱附性能。实验结果表明,M/ATZ-CC催化剂具有优异的脱硝活性和抗水性能,在反应温度为160℃、水蒸气加入量为10%(φ)、NO体积分数为0.1%、n(NH_3)∶n(NO)=1、O_2体积分数为3.0%、体积空速为3 000~10 000 h~(-1)的条件下,NO去除率在80%以上。表征结果显示,该催化剂的比表面积、孔径、弱酸酸量、中强酸酸量和总酸量得到了显著提高。

Effects of composite carrier on low-temperature denitrification activity of selective catalytic reduction catalyst

M/ATZ-CC selective catalytic reduction（SCR）catalysts was prepared by firstly dipping cordierite honeycomb ceramic in Al₂O₃-TiO₂-ZSM-5 composite carrier slurry,then loading with Mn-Fe-Ce activity component by impregnation method. The low-temperature denitrification activity and water resistance of the catalyst were studied. The physical property parameters and NH₃-temperature programmed desorption（TPD）activity of the catalyst were characterized. The experimental results indicate that the M/ATZ-CC catalysts displays excellent denitrification activity and resistivity against H₂O vapor,and the NO removal rate is more than 80% under the conditions of reaction temperature 160 ℃,H₂O vapor dosage 10%（φ）,NO volume fraction 0.1%,n（NH₃）∶n（NO）=1,O₂ volume fraction 3.0% and gas hourly space velocity（GHSV）3 000-10 000 h^-1. The characterization results show that the specific surface area,pore size and the amount of weak acid,middle-strength acid and total acid are remarkably increased.