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固定SnO2 含量为 60 % ,采用不同沉淀方法和在不同沉淀条件下制备了锡锆固溶体催化剂Sn0 4 5Zr0 55O2 ,考察了沉淀过程对其结构和性能的影响 .控制尿素浓度为总金属离子 (Sn4 ++Zr4 +)浓度的 2 0倍 ,采用均相沉淀法制备的锡锆固溶体Sn0 4 5Zr0 55O2 对催化NO还原具有最高活性和较好的重复性 ,在 3 5 0℃下最大NO转化率达到 74% .XRD ,Raman ,XPS ,BET比表面测定和孔结构分析表明 ,沉淀条件不同 ,沉淀物的成核及生长过程不同 ,对SnO2 与ZrO2 之间的固溶度、催化剂表面元素分布、比表面和孔道结构以及催化活性都有较大的影响 .ZrO2 在SnO2 (r)晶格中较高的固溶度、Sn在催化剂表面一定程度的偏析以及催化剂较大的孔径均有利于提高对NO还原反应的催化活性
The effect of precipitation process on the structure and properties of SnO 4 5Zr0 55O2 was investigated by using different precipitation methods and different precipitation conditions under different deposition conditions.The effect of the concentration of urea on the total metal ions (Sn4 + + Zr4 +). The SnO 4 5ZrO 55O2 solid solution prepared by homogeneous precipitation has the highest activity and good repeatability for the catalytic reduction of NO. The maximum NO conversion reaches 75 at 350 ℃ %. XRD, Raman, XPS, BET surface analysis and pore structure analysis show that the precipitation conditions are different, the nucleation and growth process of the precipitate is different, the solid solubility between SnO2 and ZrO2, the catalyst surface elemental distribution, And pore structure and catalytic activity have a greater impact.ZrO2 in the SnO2 (r) lattice of high solid solubility, Sn in the catalyst surface segregation to a certain extent and the catalyst larger pore size are conducive to improve the reduction of NO Catalytic activity of the reaction