High Ethylene‐Yield Oxidative Dehydrogenation of Ethane Using Sulfur Vapor as a “Soft” Oxidant

Abstract

Abstract Ethylene remains one of the most valuable chemical feedstocks. Currently the industrial conversion of ethane to ethylene is achieved largely by steam cracking. The catalytic, highly exothermic oxidative dehydrogenation (ODH) of ethane with O 2 is a challenging alternative that has been extensively studied on the laboratory scale. Here we investigate the possibility of using disulfur (S 2 ) vapor as a thermodynamically “soft” oxidant for catalytically converting ethane to ethylene (“SODH”). Investigating a series of four catalysts we report a maximum ethylene yield of 76 % over an earth‐abundant FeS x ‐based catalyst (maximum 90.2 % C 2 H 4 selectivity at 820 °C). Yield and selectivity are stable for 50 hours on stream. The SODH rate law is 1 st order in ethane and order in S 2 , supporting a proposed Mars van Krevelen‐like mechanism at temperatures <700 °C. Furthermore, conversion and selectivity become insensitive to catalyst identity at temperatures >860 °C, suggesting the intrusion of radical pathways.