摘要
采用浸渍法和共沉淀法制备了CrOx/ZrO2样品.制备过程中所得沉淀都经100℃碱液回流老化24h.通过X射线衍射、X射线光电子能谱、氮吸附、差热-热重分析等手段对样品进行了表征.结果证实,碱液回流过程中会有SiO2从所用的玻璃器皿进入样品,SiO2的表面修饰作用提高了载体的热稳定性.氧化铬的引入进一步提高了所得样品的比表面和热稳定性.与浸渍法相比,共沉淀法制备的样品具有更好的性能.其中铬锆摩尔比为0.15时,用NaOH作沉淀剂,pH值为13的条件下制备的样品在1000℃焙烧后比表面仍达到121m2·g-1.
CrOx/ZrO2 samples were prepared by impregnation method and co-precipitation method. During the preparation all the precipitates were digested at 100 degreesC in their mother liquid for 24 h. The prepared samples were characterized by XRD, XPS, BET and TGA-DTA. It was proved that some silica dissolved from the glass vessels was deposited on the precipitates during the digestion and the presence of silica increased the crystallization temperature as well as the thermal stability of zirconia. Introducing CrOx into the system resulted in a further increase in the crystallization temperature of zirconia. In addition, the specific surface area and the thermal stability of the obtained samples were also significantly improved. Compared with impregnation method, co-precipitation method gave better results and a sample with a specific surface area of 121 m(2) . g(-1) after calcination at 1000 degreesC was obtained.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2004年第3期251-255,共5页
Acta Physico-Chimica Sinica
基金
国家重点基础研究发展规划(G2000077503)
国家自然科学基金(29803001)~~
