Sugawara Yuuki, Kobayashi Hiroaki, Honma Itaru, Yamaguchi Takeo
Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, R1-17, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan.
ACS Omega. 2020 Nov 3;5(45):29388-29397. doi: 10.1021/acsomega.0c04254. eCollection 2020 Nov 17.
The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are the most critical reactions that limit the efficiency of fuel cells, water electrolyzers, and metal-air batteries. Therefore, a need exists to develop cost-effective and highly active alternative electrocatalysts for ORR and OER. This study investigates the influence of metal coordination fashion on electrocatalytic ORR and OER activities among three types of Co-Mn bimetallic oxides (CMOs): tunnel-type (CMO_T), layer-type (CMO_L), and spinel-type (CMO_S) structures. An electrochemical evaluation for CMOs verifies that CMO_L has the highest ORR and OER specific activities, which is relatively better than the previously reported bifunctional metal oxides. Additionally, atomic configuration analysis for the oxides suggests that the excellent ORR and OER activities of CMO_L result from the difference in Co and Mn coordination states. This paper not only presents an excellent electrocatalyst for alkaline fuel cells and water electrolyzers but also provides an important guideline for the design of oxygen electrocatalysts.
氧还原反应（ORR）和析氧反应（OER）是限制燃料电池、水电解槽和金属空气电池效率的最关键反应。因此，需要开发具有成本效益且高活性的ORR和OER替代电催化剂。本研究考察了三种类型的钴锰双金属氧化物（CMOs），即隧道型（CMO_T）、层状型（CMO_L）和尖晶石型（CMO_S）结构中金属配位方式对电催化ORR和OER活性的影响。对CMOs的电化学评估证实，CMO_L具有最高的ORR和OER比活性，相对优于先前报道的双功能金属氧化物。此外，对氧化物的原子构型分析表明，CMO_L优异的ORR和OER活性源于Co和Mn配位状态的差异。本文不仅为碱性燃料电池和水电解槽提供了一种优异的电催化剂，也为氧电催化剂的设计提供了重要指导。
