The oxygen evolution reaction (OER) is significant in the development and application of clean energy. Particularly, the design of highly-active and acid-stable electrocatalysts is necessary to meet large-scale requirement for water electrolysis. 

Recently, a research group led by Prof. XIAO Jianping from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) and Prof. Ryuhei Nakamura from RIKEN synthesized Co₂MnO₄ spinel, which showed high stability in acid environment for electrocatalysis. 

This study was published in Nature Catalysis on Feb. 14. 

"Density functional theoretical calculations confirmed the high activity due to the ideal binding of key intermediates from a truncated volcano activity trend," said Prof. XIAO. 

Moreover, the researchers established multi dissolution pathways to explain the high stability of Co₂MnO₄ spinel in acid environment for electrocatalysis. 

The dissolution of either Co or O was considered. Although, it showed a thermodynamic favorable for the whole reaction of dissolution, the dissolution of lattice O was found to be the most thermodynamically unfavorable elementary step in both pathways, which is the rate-limiting step. 

The Bader charge analysis indicated a larger electron transfer from Mn to O rather than that from Co to O, which revealed a stronger binding of Mn-O and a more stable lattice O in Co₂MnO₄. 

"The truncated volcano activity trend and multi dissolution pathways provided a more accurate and effective way for the rational design of catalysts for oxygen evolution reaction," said Prof. XIAO.