关键词: 钙钛矿催化剂, 火焰喷雾法合成, 一氧化碳, 废物处理, 催化

Abstract:

La_0.8Sr_0.2Mn_1-xCu_xO₃ (x=0,0.1,0.2,0.3,0.4) perovskite catalysts with Sr²⁺ and Cu²⁺ substituted at A and B sites were prepared by flame spray synthesis method for CO catalytic oxidation, and the effects of water vapor and CO₂ on the CO oxidation activity of the catalysts were investigated. The structure and catalytic activity of La_0.8Sr_0.2Mn_1-xCu_xO₃ catalysts were characterized and analyzed by XRD, SEM, EDS, BET, XPS, H₂-TPR and O₂-TPD. The catalysts prepared by flame spray synthesis exhibit good perovskite phases, loose porous structure and catalytic oxidation activity. La_0.8Sr_0.2Mn_0.9Cu_0.1O₃ achieves 50% CO and 90% CO conversion at 119.4℃ and 133.3℃, respectively. The doping of water vapor and CO₂ will form competitive adsorption with CO on the surface of the perovskite, resulting in the performance degradation of the five catalysts. And La_0.8Sr_0.2Mn_0.9Cu_0.1O₃ can achieve 90% CO conversion at 150.2℃. In the continuous stable catalytic oxidation test, the catalytic activity decreased less than 10%. Combined with the above CO catalytic oxidation experiment, the catalyst prepared by the flame spray synthesis method has good stability and catalytic activity, and is suitable for preparing a perovskite catalyst with high CO catalytic oxidation activity.

Key words: perovskite catalyst, flame spray synthesis, carbon monoxide, waste treatment, catalysis