【摘要】 微波法制备的流化床Cr-K/γ-Al₂O₃催化剂,会使得催化剂表面的晶粒度减小,活性组分分布更为均匀,比表面积增大,促使了活性Cr⁶⁺物种去占据氧化铝的四面体空隙,甚至进入到氧化铝体相结构中的四面体空穴,促使它们形成更为稳定的结构,有利于提高催化剂耐磨性和稳定性,而孤立的Cr⁶⁺、单体或低聚氧化铬在脱氢中起决定性作用。研究表明,微波辅助法制备的催化剂中最佳Cr负载量（w（Cr₂O₃）=7.5%）,相比工业FBD-4催化剂（w（Cr₂O₃）=12.5%）,降低了5.0%,可减轻催化剂使用过程中的环境压力,同时催化性能也有明显改善,运行250min。异丁烯选择性高达92.9%,收率为57.2%,积碳减少。更多还原

【Abstract】 As Cr-K/γ-Al₂O₃ catalysts,the catalytic performance of the catalysts obtained by microwave were better than by conventional method.the microwave method could decrease the particle size of active parts more evenly,and improve the degree of dispersion of active constituent on the supporter.Part of metal Cr⁶⁺species occupies sites on/in Al₂O₃ in close vicinity of tetrahedral 27 Al,forming the stable structure-Al-O-Cr-O-Al-.And the isolated Cr⁶⁺,mono and polychromate species,which seemed to play a key role in the isobutane dehydrogenation.The results showed that compared with the industrial catalyst of FBD-4(w（Cr₂O₃=7.5%）,the Cr loading(w（Cr₂O₃=7.5%）of catalyst prepared by microwave method decrease 5.0% which can reduce stress for environment on usage,the selectivity was 92.9% of isobutylene on yield of 57.2%in the reaction period of 250 min,the coke was generated slowly.更多还原