采用沉积-沉淀法制备了2%(质量分数)Au/CeO2催化剂,并用X射线衍射、投射电镜、X射线光电子能谱和程序升温还原等手段研究了纳米金催化剂在室温空气中存放和冰箱冷冻存放失活的机理.结果表明,冰箱冷冻储存更有利于抑制金纳米颗粒的长大,使催化剂保持更高的储存活性.纳米金催化剂储存失活是部分可逆的,导致其失活因素有两方面:(1)金纳米粒子的长大,导致不可逆失活;(2)表面吸附二氧化碳和水,可通过高温焙烧来恢复部分活性,属于可逆性失活.%A nanosized 2wt% Au/CeO2 catalyst was prepared using the deposition-precipition method.The deac-tivation mechanism of the catalyst stored in ambient air and frozen refrigerator was investigated using X-ray dif-fraction,transmission electron microscopy,X-ray photoelectron spectroscopy and H2 temperature-programmed reduction.The results show that refrigerator frozen storage was more advantageous to inhibit gold nanoparticles aggregation,and thus the catalyst could maintain a higher catalytic activity.The deactivation of the catalyst was partially reversible,and there were two factors leading to the deactivation.One was the agglomeration of nanos-ized gold partilces,which caused the irreversible deactivation.The other was the adsorption of carbon dioxide and water on catalyst surface,leading to the reversible deactivation.The adsorption carbonate species could be eliminated when the deactivated catalyst was calcined at high temperature.
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