焙烧温度对Au/CeO_2-La_2O_3催化剂水煤气变换性能的影响

Influence of Calcination Temperature on Au/CeO_2-La_2O_3 Catalysts for Water-Gas Shift Reaction

采用沉积沉淀法制备了Au/CeO2催化剂,通过N2物理吸附、XRD、H2-TPR和HRTEM等手段研究了焙烧温度对催化剂的织构、物相、还原性能以及WGS反应活性的影响。结果表明,焙烧温度对催化剂活性影响显著,低温焙烧有利于金粒子在载体表面的良好分散,高温焙烧则会使金粒子在载体表面聚集长大。选择适中的焙烧温度不仅可以使表面纳米金粒子获得较好的分散,而且可使Au与载体间具有适宜的相互作用,从而拥有较佳的WGS性能。在本文考察范围内,300℃焙烧4 h制得的样品在各个反应温度点上均表现了最高的WGS活性。

The influence of calcination temperature（TC） on the catalytic behavior of Au/ceria catalysts in the water-gas shift reaction was studied.Measurement of BET analysis,XRD,H2-TPR,HRTEM,showed that the high catalytic activity strongly depend on the high dispersion of gold particles and the interaction between the gold and support,which were attributed to preparation method and the calcination temperature.And perfect catalytic performance of Au/ceria catalyst was related to good dispersion of gold particles and moderate interaction between gold and support,which can be realized by appropriate thermal treatment and deposition-precipitation method.In our experiment,the deposition-precipitation sample calcined at 300 ℃ showed the best catalytic activity.