摘要
采用XRD ,XPS和TPR等手段研究了氧化铜与二氧化铈 氧化铝机械混合载体之间的表面相互作用 .结果表明 ,在混合载体表面 ,当氧化铜的负载量低于其在二氧化铈载体上的分散容量时 ,氧化铜优先与二氧化铈发生作用并分散在其表面 ;当氧化铜的负载量超过其在二氧化铈载体上的分散容量时 ,氧化铜会继续在氧化铝表面分散 .这些结果说明 ,在制备用氧化铈改性载体的负载型催化剂时 ,如果氧化铈的用量偏高 ,会导致样品中有晶相氧化铈生成 ,从而对氧化铈作为改性剂的作用不利 .
The surface interaction between copper oxide and CeO 2-γ-Al 2O 3 mixed oxide support was studied by using XRD, XPS and TPR. It was shown that the copper oxide species have stronger interaction with CeO 2 than with γ-Al 2O 3, and the copper oxide species are preferentially dispersed on the surface of CeO 2 if the loading of copper oxide species is lower than its dispersion capacity on CeO 2 support. However, the copper oxide species are dispersed on the surface of γ-Al 2O 3 if the loading of copper oxide species exceeds its dispersion capacity on CeO 2 support. These results indicated that the formation of crystalline ceria reduces the use of ceria as a promoter in the ceria-modified catalysts if the loading of ceria exceeds its dispersion capacity on the support. These results are helpful to control the loading of modifying reagent in the preparation of supported catalysts.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2002年第4期325-328,共4页
基金
教育部博士点专项基金资助项目 ( 980 2 8434)
