摘要
采用水热合成法、沉积沉淀法分别制备花球状CeO2和负载型Au／CeO2。考察了反应液pH、金的负载量和煅烧温度对Au／CeO2催化氧化CO活性的影响，确定最佳制备参数，并对优化的Au／CeO2进行稳定性、储存性和再生性测试。结果表明：反应液的最适宜pH为8．5-9，最适宜的负载量和焙烧温度分别是2％（质量分数）和300℃。优化的Au／CeO2催化剂，室温下将1％CO催化氧化至1．8×10^-6，连续反应67h活性开始下降，当温度升至55℃时，连续反应700h，CO浓度仍然保持在8×10^-6以下。此外，该催化剂还表现出良好的储存性和再生性。
The flowerlike CeO2 support and its supported catalysts Au/CeO2 was synthesized by hydrothermal and deposition-precipition method, respectively. The effect of several preparation parameters and test condition on the activity of catalysts, such as pH value of reaction solution, gold loading, calcination temperature, weight hourly space velocity, were investigated. The preparation parameters were optimized by using ambient CO oxidation as probe reac tion. It is confirmed that the best pH value is 8.5-9, optimal gold loading and calcination temperature are 2wt% and 300 ℃, respectively. In addition, the stability, humidity resistance, storage and regeneration of the optimized catalyst Au/CeO2 was also investigated. The results of activity and stability tests on the optimized Au/CeO2 catalysts showed that CO concentration was reduced from 1% to 1.× 10^- 6 at ambient temperature and remained almost unchanged over 67 h. When temperature rises to 55℃, CO concentration was always less than 8×10^-6 even after a continuous reaction of nearly 700 h. Besides, the Au/CeO2 catalysts also showed good storage stability and partially regeneration.
关键词
Au/CeO2
一氧化碳
低温催化氧化
制备参数
Au/CeO2
carbon monoxide
low-temperature catalytic oxidation
preparation parameter
