Abstract:

Perovskite-type oxides of Au-LSM and Au/LSM with 0.5%(mass) Au doping were synthesized by the coprecipitation (CP) and the deposition-precipitation (DP) processes respectively.They were tested in a flow reactor for total combustion of toluene, and characterized by XRD, BET, H₂-TPR.The results showed that Au doping did not affect the texture properties of La_0.8Sr_0.2MnO₃, but Au actually enhanced the surficial oxygen mobility of catalysts, and increased catalytic oxidation activity at a low temperature.Compared with Au/LSM, Au-LSM showed better catalytic performance, and its activity was similar to that of the commercial catalyst Pd/Al₂O₃.Au-LSM also had good stability because its performance did not change significantly after 50 h on stream in the temperature range of 280—400℃.

Key words:

金掺杂, 钙钛矿, 催化燃烧, 甲苯

摘要：

采用共沉淀（CP）和沉积-沉淀法（DP）分别制备了0.5%(质量分数)金掺杂的Au-LSM和Au/LSM钙钛矿催化剂，以甲苯催化燃烧为模型反应测试催化剂活性，并用XRD、BET、H₂-TPR对其进行表征。结果表明，Au掺杂并不改变La_0.8Sr_0.2MnO₃催化剂的织构性质，但明显增强了催化剂表面氧的活动性，提高了其低温催化氧化活性。与DP法制备的Au/LSM相比，Au-LSM表现出更好的催化性能，其催化活性与商业贵金属Pd/Al₂O₃相当。通过对焙烧温度考察以及50 h的变温活性测试，Au-LSM催化性能并没有发生较大变化，催化剂具有良好的稳定性。

关键词:

金掺杂, 钙钛矿, 催化燃烧, 甲苯