La-M-Co-O/堇青石催化剂的制备及催化氧化氯苯

Study on the preparation and catalytic oxidation of chlorobenzene over La-M-Co-O/cordierite catalysts

采用柠檬酸络合法制备La-M-Co-O(M=Mn,Cr,Fe,Ni和Cu)/堇青石催化剂,运用BET,XRD,SEM,H2-TPR和XPS技术对催化剂性能及微观结构进行表征分析,研究考察过渡金属掺杂,掺杂量以及焙烧温度等对催化剂催化氧化性能的影响.结果表明,随着催化剂焙烧温度升高至650℃时,催化剂表面所负载的活性氧化物颗粒最为分散,其氧化活性最佳,且当反应温度为350℃时,催化剂催化氧化氯苯转化率可达96.4%,究其原因是高温焙烧致使催化剂形成LaCoO3钙钛矿型复合氧化物,其复合氧化物的晶体结构有利于催化剂催化氧化氯苯性能的提高.

La-M-Co-O(M=Mn,Cr,Fe,Ni and Cu)/cordierite catalysts were prepared by complexation method with citric acid.BET,XRD,SEM,H2-TPR and XPS technologies were used to characterize and analyze the performance and microstructure of these catalysts.Meanwhile,the influences of the types of transition metal,the amount transition metal and calcination temperature were studied.The results show that when the calcination temperature was 650℃,the active oxide particles supported on the surface of the catalysts were the most dispersed and displayed the best activity for chlorobenzene oxidation.And when the reaction temperature was 350℃,the conversion rate is as high as 96.4%.The main reason was that the catalysts displayed the structure of LaCoO3 perovskite composite oxides attribute to the high calcination temperature,which was beneficial for improving the performance of catalytic oxidation of chlorobenzene over composite catalysts.