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采用凝胶溶胶法制备TiO2以及摩尔比分别为1:1和4:1的TiO2-ZrO2三种载体,然后浸渍负载一定量的活性组分MnOx制备相应催化剂.通过X射线衍射和扫描电镜对载体和催化剂进行表征,并进行氨气低温选择性催化还原NO(NH3-SCR)实验来考察催化剂的活性.三种载体中TiO2-ZrO2(4:1)的颗粒粒径最小且高度分散,加入氧化锆后,Zr4+离子取代Ti4+离子掺杂进入TiO2晶格内,引起TiO2晶格畸变,抑制TiO2晶型转变,并促进载体上活性组分Mn的均匀分布,从而提高催化剂的低温选择性催化还原活性.TiO2-ZrO2(4:1)加入质量分数10%的Mn后催化剂的活性最高,在130℃采用该催化剂催化时NO的转化率达到92.6%;150℃时通入体积分数10%的水蒸气会降低10%Mn/TiO2-ZrO2(4:1)催化剂的活性,撤消后活性可逐渐恢复;而200℃时10%Mn/TiO2-ZrO2(4:1)的活性基本不受水蒸气的影响.
TiO 2 and three kinds of TiO 2 -ZrO 2 with molar ratio of 1: 1 and 4: 1 respectively were prepared by sol-gel method, then impregnated with a certain amount of active component MnOx to prepare the corresponding catalyst.X-ray diffraction and scanning electron microscopy (NH3-SCR) was used to investigate the catalytic activity of the catalysts.The catalytic activity of TiO2-ZrO2 (4: 1) particles was the smallest and highly dispersed in the three carriers, Zirconium, Zr4 + ions instead of Ti4 + ion doping into the TiO2 lattice, causing TiO2 lattice distortion, inhibition of TiO2 crystal transition, and to promote the uniform distribution of the active ingredient Mn carrier, thereby enhancing the catalyst for low-temperature selective catalytic reduction activity When TiO2-ZrO2 (4: 1) was added into 10% Mn, the catalytic activity was the highest, and the conversion rate of NO reached 92.6% when catalyzed by the catalyst at 130 ℃. When the temperature was 150 ℃, 10% The activity of 10% Mn / TiO2-ZrO2 (4: 1) catalyst can be reduced, and the activity of the catalyst can be gradually restored after being withdrawn. However, the activity of 10% Mn / TiO2- .