摘要
制备了碱金属M(M=Na,K,Rb和Cs)掺杂的Au-Pt/CeO2催化剂,考察了其催化水煤气变换反应的活性,并采用X射线衍射、H2程序升温还原、紫外-可见漫反射光谱和X射线光电子能谱技术研究了K助剂对Au-Pt/CeO2催化剂结构和表面性质的影响.结果表明,添加少量电负性较低的K虽然使Pt的还原变得困难,但有利于Au金属态的稳定,并使催化剂表面Ce3+富集而产生氧空位,显著提高了Au-Pt/CeO2催化剂活性.当K负载量为0.025%,反应温度250℃时,CO转化率可达95%.
Au-Pt/CeO2 catalyst samples modified with alkali metals M（M=Na,K,Rb,and Cs） were prepared and their catalytic activity for water-gas shift（WGS） was evaluated.The structure and surface properties of the Au-Pt/CeO2 catalyst promoted by potassium were investigated by X-ray powder diffraction,H2 temperature-programmed reduction,ultraviolet-visible diffuse reflectance spectroscopy,and X-ray photoelectron spectroscopy.The higher activity obtained on the K-promoted Au-Pt/CeO2 sample was possibly due to the reduction of Au3＋ species and the enrichment of Ce3＋ on the catalyst surface,which generated more oxygen vacancies.The catalytic activity of Au-Pt/CeO2 was greatly influenced by the alkali metals.When the K content was 0.025%,the CO conversion achieved up to 95% at 250℃.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2010年第6期671-676,共6页
基金
国家自然科学基金(20473070
20973148)
山东省科技攻关计划(2009GG10007022)
关键词
氧化铈
铂
金
钾
助剂
水煤气变换反应
ceria
platinum
gold
potassium
promoter
water-gas shift
