Research and development of mixed-anion compounds as efficient oxygen evolution electrocatalysts

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K15678
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 36020:Energy-related chemistry
• Research Institution: Kyoto University
• Principal Investigator: Miyahara Yuto 京都大学, 工学研究科, 助教 (60807816)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 二次電池 / 水電解 / 酸素発生触媒 / 複合アニオン化合物

Outline of Final Research Achievements

Alkaline water electrolyzers and metal-air rechargeable batteries, which use electrochemical oxygen evolution reaction (OER), are attractive energy conversion devices due to their environmentally friendliness. In this research, I focused on mixed-anion compounds for efficient OER electrocatalysts. In addition to perovskite oxychlorides, which we have found highly active, oxyfluorides and oxynitrides also showed higher OER activities than the corresponding oxides. Through characterizations, we proposed that the OER on the oxychlorides took place via a novel dual-site pathway. The selection of transition-metal cations was also an important factor to obtain high OER activity, and therefore proper combination of effective cation and anion will further enhance the OER activity. By using the highly active mixed-anion catalyst, the OER overpotential was successfully reduced by 200 mV compared with a corresponding conventional oxide catalyst.

Free Research Field

電気化学

Academic Significance and Societal Importance of the Research Achievements

アニオン組成に着目した酸素発生触媒の検討は世界的にも珍しく、高活性化の要因と併せて明確にすることで触媒探索の可能性を拡げることができた。本研究によって得られた知見は高活性な酸素発生触媒の創製へ向けた新たな設計指針を提供するものであり、上記デバイスの普及へ向けて有益な成果が得られたといえる。