论文部分内容阅读
合成了Cu/Al原子比分别为2.0、3.1、4.1的CuAl类水滑石样品,焙烧得到CuAl复合氧化物。在Cu/Al原子比为3.1的CuAl氧化物表面浸渍碱金属盐溶液,制备改性CuAl复合氧化物,用AES、XRD、FT-IR、BET、H2-TPR、XPS等技术对催化剂进行了结构表征,考察了CuAl复合氧化物组成、碱金属助剂类型和K的前驱物对改性催化剂在有氧气氛中催化分解N2O活性的影响。结果表明,Na、K、Cs改性CuAl复合氧化物均提高了催化剂活性,但K助剂的增强效应最显著;钾的不同前驱物改性CuAl复合氧化物的催化活性有显著差异,加入碳酸钾、草酸钾提高了催化剂的活性,而加入醋酸钾、硝酸钾反而降低了催化剂活性。优化出的K改性CuAl复合氧化物催化剂在含氧含水气氛的N2O分解反应中表现出了较高的活性。
CuAl-type hydrotalcite samples with Cu / Al atomic ratios of 2.0, 3.1 and 4.1 were synthesized and calcined to obtain CuAl composite oxides. A CuAl composite oxide was prepared by impregnating CuAl oxide with a Cu / Al atomic ratio of 3.1 on the surface of the catalyst. The structure of the catalyst was characterized by AES, XRD, FT-IR, BET, H2-TPR and XPS The effects of the composition of CuAl composite oxides, the types of alkali metal additives and the precursors of K on the catalytic activity of the modified catalysts for the catalytic decomposition of N 2 O in an aerobic atmosphere were investigated. The results showed that all of Cu, Cu, and Cs modified CuAl composite oxides increased the catalytic activity, but the enhancement effect of K promoter was the most significant. The catalytic activity of different precursors modified CuAl composite oxides was significantly different. Potassium and potassium oxalate increase the activity of the catalyst, while addition of potassium acetate and potassium nitrate decreases the activity of the catalyst. The optimized K-modified CuAl composite oxide catalyst showed higher activity in the N2O decomposition reaction in an oxygen-containing aqueous atmosphere.