title: Bifunctional Perovskite Oxide Catalysts for Oxygen Reduction and Evolution in Alkaline Media.
abstract: Oxygen electrocatalysis, namely of the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER), governs the performance of numerous electrochemical energy systems such as reversible fuel cells, metal-air batteries, and water electrolyzers. However, the sluggish kinetics of these two reactions and their dependency on expensive noble metal catalysts (e.g, Pt or Ir) prohibit the sustainable commercialization of these highly innovative and in-demand technologies. Bifunctional perovskite oxides have emerged as a new class of highly efficient non-precious metal catalysts (NPMC) for oxygen electrocatalysis in alkaline media. In this review, we discuss the state-of-the-art understanding of bifunctional properties of perovskites with regards to their OER/ORR activity in alkaline media and review the associated reaction mechanisms on the oxides surface and the related activity descriptors developed in the recent literature. We also summarize the present strategies to modify their electronic structure and to further improve their performance for the ORR/OER through highlighting the new concepts relating to the role of surface redox chemistry and oxygen deficiency of perovskite oxides for the ORR/OER activity. In addition, we provide a brief account of recently developed advanced perovskite-nanocarbon hybrid bifunctional catalysts with much improved performances.
authors.affiliation: Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York, 14260, United States.
authors.forename: Shiva
authors.initials: S
authors.lastname: Gupta
authors.affiliation: Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York, 14260, United States.
authors.forename: William
authors.initials: W
authors.lastname: Kellogg
authors.affiliation: Giner Inc., Newton, MA, 02466, United States.
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.affiliation: School of Energy and Chemical Engineering, National Institute of Science and Technology (UNIST), Ulsan, 689-798, Korea.
authors.forename: Xien
authors.initials: X
authors.lastname: Liu
authors.affiliation: School of Energy and Chemical Engineering, National Institute of Science and Technology (UNIST), Ulsan, 689-798, Korea. jpcho@unist.ac.kr.
authors.forename: Jaephil
authors.initials: J
authors.lastname: Cho
authors.affiliation: Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York, 14260, United States. gangwu@buffalo.edu.
authors.forename: Gang
authors.initials: G
authors.lastname: Wu
keywords: electrocatalyts; energy conversion and storage; oxygen evolution; oxygen reduction; perovskite oxide