助剂负载量和焙烧温度对K/CuAl复合氧化物催化分解N_2O性能的影响

采用共沉淀法合成了CuAl类水滑石,焙烧后得到CuAl复合氧化物,再等体积浸渍K2CO3溶液,制得K改性CuAl复合氧化物催化剂K/CuAl;采用XRD,BET,H2-TPR,XPS等技术对K/CuAl催化剂进行了结构表征,考察了K负载量和焙烧温度对K/CuAl催化剂在有氧气氛中催化分解N2O活性的影响。实验结果表明,负载K显著提高了CuAl复合氧化物催化分解N2O的活性,其中K与Cu的原子比为0.10、400℃焙烧的K/CuAl催化剂的活性最高,该催化剂在N2O分解反应中表现出了较好的稳定性,在500℃下连续反应10 h,有氧气氛中N2O转化率接近90%,而有氧有水气氛中N2O转化率接近60%,说明K的引入显著提高了催化剂的抗氧及抗水性能。

Effect of K Loading and Calcination Temperature on Catalytic Performance of K/CuAl Composite Oxides for N2O Decomposition

K-doped CuAl composite oxides(K/CuAl) were prepared by an isochoric impregnation of CuAl composite oxide with K2CO3solution,which was prepared by calcination of CuAl hydrotalcitelike compound obtained by a co-precipitation method,and characterized by means of XRD,BET,H2-TPR and XPS.The effects of K loading and calcination temperature on the activity of K/CuAl for N2O decomposition in the presence of oxygen were investigated.The results show that the catalytic activity of K/CuAl,especially the one with the atom ratio of K to Cu 0.10 calcined at 400 ℃,was significantly enhanced by the addition of K species.The optimized K/CuAl catalyst exhibited a good stability in N2O decomposition,the N2O conversion could be 90% or 60% at 500 ℃ for 10 h with the feed gases containing oxygen or both oxygen and steam,respectively.The resistances of the catalyst to oxygen and water were evidently improved by the addition of K.