Mechanism of oxidative dehydrogenation of Propane over hexagonal boron nitride catalyst

The research group of catalysis and reaction engineering of School of chemistry and chemical engineering of Xiamen University has made progress in the study of mechanism of oxidative dehydrogenation of Propane over hexagonal boron nitride (h-BN) catalyst Relevant achievements were published in science advances (DOI: 10.1126 / sciadv.aav8063) under the title of "proactive dehydration over highly selective hexagonal boron nitridecatalysts: the role of oxidative coupling of metal" Compared with the traditional vanadium based catalysts, h-BN catalysts show excellent olefin selectivity in the oxidative dehydrogenation of propane In addition to the main product propylene, it also obtains high ethylene selectivity However, the process of oxidative dehydrogenation of Propane over h-BN catalyst is still lack of deep understanding It is generally believed that C2 products are produced by C-C bond breaking of propane on h-BN catalyst, so the selectivity ratio (C2 / C1) of C2 and C1 products should be less than or equal to 2 However, it was found that C2 / C1 of more than 2 can be obtained by h-BN catalyst under certain conditions In view of this abnormal phenomenon, after a lot of experimental research, the research group put forward the hypothesis that the methyl radicals produced by C-C bond breaking further oxidative coupling produce C2 products, and explained the phenomenon of high selectivity of C2 products in the oxidative dehydrogenation of Propane over h-BN catalyst The above hypotheses were verified by methane oxidation experiment, isotope (13C) labeling experiment and on-line mass spectrometry tracking Four possible reaction paths of methyl radicals in oxidative dehydrogenation of Propane over h-BN catalyst were proposed This discovery is of great significance to re understand the oxidative dehydrogenation of Propane over h-BN catalyst, and also provides a new idea for the study of selective oxidation and conversion of low-carbon alkanes In recent years, the research group of catalysis and reaction engineering has been committed to the basic and Application Research of low-carbon alkane catalytic conversion, especially in the selective oxidation of low-carbon alkane over boron based catalysts, which is forming its own research characteristics, and has made a series of progress in the selective conversion of methane, ethane and propane to high value-added chemicals (Chemical Engineering Science, 2018, 186 , 14; AIChE Journal , 2018 , 64 , 4002 ）。 The research work was completed under the guidance of Professor Wang Yong and Associate Professor Lin Jingdong Tian Jinshu, a doctoral candidate of 2015, Tan Jiangqiao, a graduate of 2015 and Xu Mingliang, a graduate of 2016, jointly completed the relevant experiments and catalyst characterization Zhang Chaoxia, an engineer, Wan Shaolong, an associate professor, and Wang Shuai participated in the research This work was supported by the National Natural Science Foundation of China (project approval No.: 21576227, 91545114, 91545203, 21673189) and the basic scientific research business expenses of Central University (project approval No.: 20720160032).