Isobutane dehydrogenation over chromia alumina catalysts prepared from MIL-101: Insight into chromium species on activity and selectivity  

作　　者：Huahua Zhao Huanling Song Zhichao Miao Lingjun Chou 

机构地区：[1]State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences [2]Institute of Nano-Tech and Nano-Bionics [3]University of Chinese Academy of Sciences

出　　处：《Journal of Energy Chemistry》2014年第6期708-716,共9页能源化学（英文版）

基　　金：supported by the National Basic Research Program of China(No.2011CB201404);the National Natural Science Foundation of China(No.21133011);Suzhou Science and Technology Bureau of Applied Foundation Research Project(SYG201219)

摘　　要：Various mesoporous chromia alumina catalysts were prepared by five different methods based on a metal-organic framework MIL-101 and their catalytic performances over isobutane dehydrogenation were investigated. The highly dispersed chromium species were produced on catalyst KCrAI-I1 with largest specific surface area of 198 m2-g-1 prepared with aluminium isopropoxide （Al（i-OC3HT）3） by ultrasonic im- pregnation method. However, the catalyst KCrAI-I2 synthesized by stirring impregnation possessed crystalline a-Cr203 phase, which was poorly dispersed. Two types of Cr-rich and Al-rich CrzA12_zO3 solid solutions, designated as CrAI-I and CrAI-II phase, were formed over the catalysts KCrAI-I3 （prepared by Al（i-OC3HT）3 with nitric acid regulation）, KCrA1-C4 （prepared by aluminium chloride hexahydrate） and KCrA1-N5 （prepared by aluminium nitrate nonahydrate）. Catalytic evaluation results revealed that KCrAI-I1 exhibited the high isobutane con- version due to its highly dispersed chromium species. However, KCrAI-I3, KCrA1-C4 and KCrA1-N5 showed the higher isobutene selectivity （95.2%-96.4%） on account of the formation of chromia alumina solid solutions in the catalysts. Moreover, the solid solution over the chromia alumina catalysts could greatly suppress the coke formation.Various mesoporous chromia alumina catalysts were prepared by five different methods based on a metal-organic framework MIL-101 and their catalytic performances over isobutane dehydrogenation were investigated. The highly dispersed chromium species were produced on catalyst KCrAI-I1 with largest specific surface area of 198 m2-g-1 prepared with aluminium isopropoxide （Al（i-OC3HT）3） by ultrasonic im- pregnation method. However, the catalyst KCrAI-I2 synthesized by stirring impregnation possessed crystalline a-Cr203 phase, which was poorly dispersed. Two types of Cr-rich and Al-rich CrzA12_zO3 solid solutions, designated as CrAI-I and CrAI-II phase, were formed over the catalysts KCrAI-I3 （prepared by Al（i-OC3HT）3 with nitric acid regulation）, KCrA1-C4 （prepared by aluminium chloride hexahydrate） and KCrA1-N5 （prepared by aluminium nitrate nonahydrate）. Catalytic evaluation results revealed that KCrAI-I1 exhibited the high isobutane con- version due to its highly dispersed chromium species. However, KCrAI-I3, KCrA1-C4 and KCrA1-N5 showed the higher isobutene selectivity （95.2%-96.4%） on account of the formation of chromia alumina solid solutions in the catalysts. Moreover, the solid solution over the chromia alumina catalysts could greatly suppress the coke formation.

关 键 词：isobutane dehydrogenation chromia alumina solid solution metal organic framework MIL-IO1 

分 类 号：O643.36[理学—物理化学]