Ga_2O_3催化剂上CO_2气氛中丙烷脱氢反应的研究  

Dehydrogenation of Propane to Propene in the Presenceof CO_2 over Gallium Oxide

作　　者：郑波[1] 华伟明[1] 乐英红[1] 高滋[1] 

机构地区：[1]复旦大学化学系上海市分子催化和功能材料重点实验室,上海200433

出　　处：《高等学校化学学报》2005年第9期1726-1731,共6页Chemical Journal of Chinese Universities

基　　金：国家重点基础研究发展规划项目(批准号:G2000077507);国家自然科学基金(批准号:20303004);上海市重大基础研究基金(批准号:03DJ14004);上海市自然科学基金(批准号:03ZR14013)资助.

摘　　要：考察了Ga2O3对于丙烷脱氢和CO2气氛脱氢反应的催化性能.结果表明,Ga2O3具有较高的催化活性,其性能优于传统的Cr2O3脱氢催化剂.催化反应可能经过了一个丙烷异裂的过程,其中CO2是通过逆水煤气反应和Boudouard反应来促进催化剂性能的,在高于823K时该促进作用更为明显.催化剂的催化活性和其表面酸密度密切相关,在Ga2O3结构中,四配位Ga3+是其酸位的来源,并通过质子与氧化物的共同作用促进反应进行.催化剂的失活是由于表面的积碳和活性氧的消耗共同造成的.同时还对Ga2O3作为丙烷脱氢反应的催化剂的催化反应机理进行了初步探讨.Dehydrogenation of propane to propene in the presence or absence of CO2 over gallium oxide was investigated. Ga2O3 exhibited the high dehydrogenation activity, which was even more active than chromium oxide catalyst. The dehydrogenation reaction was suggested to proceed through a heterolytic dissociation reaction pathway instead of a redox mechanism, and it was enhanced by CO2 due to the existence of the reverse water gas shift reaction and the Boudouard reaction. This promotion effect of CO2 was more evident at above 823 K. The high catalytic activity of Ga2O3 was probably associated with an abundance of surface mediumstrong acid sites related to the coordinatively unsatured Ga^3＋ cations and the conjugated effect of proton and oxide. The deactivation of the catalyst was due to the coke deposition as well as the loss of the active oxygen species on the surface which could not be recovered during the regeneration.

关 键 词：GA2O3 丙烷 脱氢 CO2 反应机理 

分 类 号：O643.1[理学—物理化学]