Enhanced stability of Pt/Al_(2)O_(3) modified by Zn promoter for catalytic dehydrogenation of ethane  

作　　者：Xiaoyu Li Yanliang Zhou Botao Qiao Xiaoli Pan Chaojie Wang Liru Cao Lin Li Jian Lin Xiaodong Wang 

机构地区：[1]CAS Key Laboratory of Science and Technology on Applied Catalysis,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,Liaoning,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Journal of Energy Chemistry》2020年第12期14-20,共7页能源化学（英文版）

基　　金：supported by the National Natural Science Foundation of China (NNSFC 21573232, 21576251, 21676269, 21878283);the Strategic Priority Research Program of Chinese Academy of Sciences Grant No. XDB17000000;National Key Projects for Fundamental Research and Development of China (2016YFA0202801);The Youth Innovation Promotion Association CAS (2017223);Department of Science and Technology of Liaoning province under contract of 2015020086-101。

摘　　要：Catalytic ethane dehydrogenation(EDH) to ethylene over Pt-based catalysts has received increasing interests in recent years as it is a potential alternative route to conventional steam cracking. However, the catalysts used in this reaction often suffer from rapid deactivation due to serious coke deposition and metal sintering. Herein, we reported the effects of Zn modification on the stability of Pt/Al2 O3 for EDH.The Zn-modified sample(PtZn2/Al2 O3) exhibits stable ethane conversion(20%) with over 95% ethylene selectivity. More importantly, it exhibits a significantly low deactivation rate of only 0.003 h-1 at 600 °C for70 h, which surpasses most of previously reported catalysts. Detailed characterizations including in situ FT-IR, ethylene adsorption microcalorimetry, and HAADF-STEM etc. reveal that Zn modifier reduces the number of Lewis acid sites on the catalyst surface. Moreover, it could modify Pt sites and preferentially cover the step sites, which decrease surface energy and retard the sintering of Pt particle, then prohibiting the further dehydrogenation of ethylene to ethylidyne. Consequently, the good stability is realized due to anti-sintering and the decrease of coke formation on the Pt Zn2/Al2 O3 catalyst.

关 键 词：Catalytic dehydrogenation of ethane STABILITY PtZn/Al2O3 Zn promoter COKE 

分 类 号：TQ221.211[化学工程—有机化工] TQ426