Mass Spectrometric Studies of Selective Oxidation of n-Butane over a Vanadium Phosphorus Oxide Catalyst  

作　　者：陈标华 黄晓峰 李成岳 梁日忠 赵邦蓉 

机构地区：[1]The Key Lab of Science and Technology of Controllable Chemical Reactions [2]College of Material Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China

出　　处：《Chinese Journal of Chemical Engineering》2002年第2期177-182,共6页中国化学工程学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China (No. 29792073-3).

摘　　要：The selective oxidation of n-butane to maleic anhydride (MA) on a vanadium-phosphorus oxide (VPO) catalyst was studied using on-line gas-chromatography combined with mass spectrometry(GC-MS) and transient response technique. The reaction intermediates, buterie and furan, were found in the reaction effluent under near industrial feed condition (3% butane+15%O2), while dihydrofuran was detected at high butane concentration (12% butane, 5%O2). Some intermediates of MA decomposition were also identified. Detection of these intermediates shows that the vanadium phosphorus oxides are able to dehydrogenate butane to butene, and butene further to form MA. Based on these observations, a modified scheme of reaction network is proposed. The transient experiments show that butane in the gas phase may directly react with oxygen both on the surface and from the metal oxide lattice, without a proceeding adsorption step. Gas phase oxygen can be adsorbed and transformed to surface lattice oxygen but it can not participate in selective oxidation. Adsorbed oxygen leads to deep oxidation, while lattice oxygen leads to selective oxidation.The selective oxidation of n-butane to maleic anhydride (MA) on a vanadium-phosphorus oxide (VPO)catalyst was studied using on-line gas-chromatography combined with mass spectrometry(GC-MS) and transientresponse technique. The reaction intermediates, butene and furan, were found in the reaction effluent under nearindustrial feed condition (3% butane+15%O2), while dihydrofuran was detected at high butane concentration (12%butane, 5%O2). Some intermediates of MA decomposition were also identified. Detection of these intermediatesshows that the vanadium phosphorus oxides are able to dehydrogenate butane to butene, and butene further to formMA. Based on these observations, a modified scheme of reaction network is proposed. The transient experimentsshow that butane in the gas phase may directly react with oxygen both on the surface and from the metal oxidelattice, without a proceeding adsorption step. Gas phase oxygen can be adsorbed and transformed to surface latticeoxygen but it can not participate in selective oxidation. Adsorbed oxygen leads to deep oxidation, while latticeoxygen leads to selective oxidation.

关 键 词：n-butane selective oxidation vanadium phosphorus oxide catalyst mass spectrometer reaction in- termediates transient response 

分 类 号：O657.3[理学—分析化学]