期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:2019
卷号:116
期号:47
页码:23473-23479
DOI:10.1073/pnas.1901046116
出版社:The National Academy of Sciences of the United States of America
摘要:The layered oxide Na 0.67 CoO 2 with Na + occupying trigonal prismatic sites between CoO 2 layers exhibits a remarkably high room temperature oxygen evolution reaction (OER) activity in alkaline solution. The high activity is attributed to an unusually short O–O separation that favors formation of peroxide ions by O − –O – interactions followed by O 2 evolution in preference to the conventional route through surface O–OH – species. The dependence of the onset potential on the pH of the alkaline solution was found to be consistent with the loss of H + ions from the surface oxygen to provide surface O − that may either be attacked by solution OH − or react with another O − ; a short O–O separation favors the latter route. The role of a strong hybridization of the O–2 p and low-spin Co III /Co IV π-bonding d states is also important; the OER on other Co III /Co IV oxides is compared with that on Na 0.67 CoO 2 as well as that on IrO 2 ..