摘要
采用共沉淀法制备了2.5%Au/ZnO催化剂,并用扫描隧道显微镜、X射线衍射、X射线光电子能谱和热重研究了纳米金催化剂在空气中存放失活的机理.结果表明,纳米金催化剂在空气中存放失活是部分可逆的.纳米金催化剂的存放失活有两方面原因:一是纳米金粒子的长大,导致不可逆失活;二是碳酸盐在催化剂表面的累积,这种失活可以通过高温焙烧来恢复,是可逆的.
A nanosized 2.5% Au/ZnO catalyst was prepared using the coprecipitation method at low temperature. The deactivation mechanism of the catalyst stored in ambient air was investigated using scanning transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The deactivation of the catalyst was partially reversible, and two factors interrelated the deactivation. One was the agglomeration of nanosized gold particles, which caused the irreversible deactivation. The other was the accumulation of carbonates on the catalyst surface, leading to the reversible deactivation. The carbonates could be decomposed when the deactivated catalyst was calcined at high temperature.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2007年第2期148-152,共5页
基金
国家自然科学基金(20643005).
关键词
纳米粒子
金
氧化锌
负载型催化剂
一氧化碳氧化
失活机理
碳酸盐
nanoparticle
gold
zinc oxide
supported catalyst
carbon monoxide oxidation
deactivation mechanism
carbonate
