酸性溶液中锰钴尖晶石具有超长析氧反应耐久性

非贵金属过渡金属氧化物的耐久性从日、周提升到月。电流密度下降了一个数量级，但是耐久性提升了两个数量级。

Enhancing the stability of cobalt spinel oxide towards sustainable oxygen evolution in acid

Ailong Li，

Shuang Kong，

Chenxi Guo，

Hideshi Ooka，

Kiyohiro Adachi，

Daisuke Hashizume，

Qike Jiang，

Hongxian Han，

Jianping Xiao ＆

Ryuhei Nakamura

Abstract

Active and stable electrocatalysts for the oxygen evolution reaction are required to produce hydrogen from water using renewable electricity． Here we report that incorporating Mn into the spinel lattice of Co3O4 can extend the catalyst lifetime in acid by two orders of magnitude while maintaining the activity． The activation barrier of the obtained spinel Co2MnO4 is comparable to that of state－of－the－art iridium oxides， most probably due to the ideal binding energies of the oxygen evolution reaction intermediates， as shown using density functional theory calculations． The calculations also show that the thermodynamic landscape of Co2MnO4 suppresses dissolution， which results in a lifetime of over 2 months （1，500 hours） at 200 mA cm−2geo at pH 1． As the lifetimes of other 3d metal oxygen evolution catalysts are in the order of days and weeks， despite current densities being lower by an order of magnitude， our results are an important step towards the realization of noble－metal－free water electrolysers．

Ryuhei Nakamura

We work on the development of biologically inspired catalysts and their application to energy conversion and production systems． Specifically， we aim to understand nature’s ingenuity towards multielectron transfer catalysis， electron／proton transport， metabolic regulation， responsiveness to external stimuli， and energy management in deep sea environments to develop the novel materials and systems necessary to effectively manage renewable energy sources．

Subjects

Development of water splitting catalysts

Investigation of giant electro－ecosystems in a deep hydrothermal environment

Microbial Electricity generation

http：／／www．csrs．riken．jp／en／labs／bcrt／index．html