Alkali metal halide-coated perovskite redox catalysts for anaerobic oxidative dehydrogenation of n-butane

Yunfei Gao; Xijun Wang; Noel Corolla; Tim Eldred; Arnab Bose; Wenpei Gao; Fanxing Li

doi:10.1126/sciadv.abo7343

Alkali metal halide-coated perovskite redox catalysts for anaerobic oxidative dehydrogenation of n-butane

Sci Adv. 2022 Jul 29;8(30):eabo7343. doi: 10.1126/sciadv.abo7343. Epub 2022 Jul 27.

Authors

Yunfei Gao^{1

2}, Xijun Wang^{1

3}, Noel Corolla¹, Tim Eldred¹, Arnab Bose¹, Wenpei Gao¹, Fanxing Li¹

Affiliations

¹ North Carolina State University, Campus Box 7905, Raleigh, NC 27695-7905, USA.
² Institute of Clean Coal Technology, East China University of Science and Technology, Shanghai 200237, China.
³ Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, USA.

Abstract

Oxidative dehydrogenation (ODH) of n-butane has the potential to efficiently produce butadiene without equilibrium limitation or coke formation. Despite extensive research efforts, single-pass butadiene yields are limited to <23% in conventional catalytic ODH with gaseous O₂. This article reports molten LiBr as an effective promoter to modify a redox-active perovskite oxide, i.e., La_0.8Sr_0.2FeO₃ (LSF), for chemical looping-oxidative dehydrogenation of n-butane (CL-ODHB). Under the working state, the redox catalyst is composed of a molten LiBr layer covering the solid LSF substrate. Characterizations and ab initio molecular dynamics (AIMD) simulations indicate that peroxide species formed on LSF react with molten LiBr to form active atomic Br, which act as reaction intermediates for C─H bond activation. Meanwhile, molten LiBr layer inhibits unselective CO₂ formation, leading to 42.5% butadiene yield. The redox catalyst design strategy can be extended to CL-ODH of other light alkanes such as iso-butane conversion to iso-butylene, providing a generalized approach for olefin production.