老化对钴铈基催化剂催化氧化丙烷的影响

采用柠檬酸络合法合成Co-CeO_x多活性中心催化剂，在不同温度进行加速老化处理，测试新鲜和老化后催化剂对丙烷的催化氧化性能，同时对其结构和性质进行表征.结果表明，当加速老化温度低于650℃时，丙烷转化率达50%的温度变化幅度小于10℃；加速老化温度高于750℃时，催化剂氧化丙烷的性能快速下降.表征结果显示，Co-CeO_x催化剂主要表现为尖晶石结构，老化后晶粒尺寸显著增大，Co³⁺的含量减少，氢还原峰温度升高.加速老化处理对Co-CeO_x催化剂物理结构的影响进而抑制了其化学特性及催化活性.测试Co-CeO_x催化剂对丙酮和甲苯的催化氧化性能，分别在179和244℃达到90%的脱除效率.因此，Co-CeO_x多活性中心催化剂具有良好的氧化性能，且表现出一定的稳定性.

Effect of aging on propane catalytic oxidation over Co-Ce catalyst

A series of Co-CeO_x catalyst were prepared via citric acid complex method and accelerated aging at different temperatures. The fresh and aged catalysts were tested for propane catalytic oxidation, and its structure and properties were characterized. The results showed that when the accelerated aging temperature was lower than 650℃, the temperature range of propane conversion up to 50% was less than 10℃; when the accelerated aging temperature was higher than 750℃, the catalytic activity of the catalyst decreases rapidly. Characterization results showed that the main structure of Co-CeO_x catalyst is spinel. After aging, the grain size increased significantly, the concentration of Co³⁺ species decreased, and the temperature of hydrogen reduction peaks were right shifted. The effect of accelerated aging treatment on the physical structure of Co-CeO_x catalyst further inhibited its chemical properties and catalytic activity. At the same time, the catalytic oxidation activity for acetone and toluene was also tested. The removal efficiency of the catalyst was 90% at 179 and 244℃, respectively. Therefore, Co-CeO_x multi active sites catalyst has good oxidation performance and stability.A series of Co-CeO_x catalyst were prepared via citric acid complex method and accelerated aging at different temperatures. The fresh and aged catalysts were tested for propane catalytic oxidation, and its structure and properties were characterized. The results showed that when the accelerated aging temperature was lower than 650℃, the temperature range of propane conversion up to 50% was less than 10℃; when the accelerated aging temperature was higher than 750℃, the catalytic activity of the catalyst decreases rapidly. Characterization results showed that the main structure of Co-CeO_x catalyst is spinel. After aging, the grain size increased significantly, the concentration of Co³⁺ species decreased, and the temperature of hydrogen reduction peaks were right shifted. The effect of accelerated aging treatment on the physical structure of Co-CeO_x catalyst further inhibited its chemical properties and catalytic activity. At the same time, the catalytic oxidation activity for acetone and toluene was also tested. The removal efficiency of the catalyst was 90% at 179 and 244℃, respectively. Therefore, Co-CeO_x multi active sites catalyst has good oxidation performance and stability.