Extensive Active-Site Formation in Trirutile CoSb2O6 by Oxygen Vacancy for Oxygen Evolution Reaction in Anion Exchange Membrane Water Splitting
SCIE
SCOPUS
- Title
- Extensive Active-Site Formation in Trirutile CoSb2O6 by Oxygen Vacancy for Oxygen Evolution Reaction in Anion Exchange Membrane Water Splitting
- Authors
- Ham, Kahyun; HONG, SUK HWA; Kang, Sinwoo; CHO, KANGWOO; Lee, Jaeyoung
- Date Issued
- 2021-02-12
- Publisher
- AMER CHEMICAL SOC
- Abstract
- Here, we first report an octahedral Co2+-rich Co oxide with inactive Sb5+ ion as an oxygen evolution reaction (OER) electrocatalyst for efficient H-2 production by lowering the cell voltage in anion exchange membrane water splitting (AEMS). To enhance the OER activity of Co-based oxides, it is crucial to increase the amount of Co4+ at OER potential, known as the fast OER active site. Using in situ X-ray absorption spectroscopy, we observed most of the octahedral Co2+ in trirutile CoSb2O6 oxidized to Co3+ before the OER potential. Furthermore, oxygen vacancies facilitated further oxidation from Co3+ to Co4+ by tuning OH- adsorption energy of Co and then produced extensive active sites for O-O bond formation in OER compared to spinel-type Co3O4. As a result, we obtained a much lower OER overpotential of 360 mV at 100 mA/cm(2), providing 88% of the highest H-2 energy efficiency in the AEMS by applying a cell voltage of 1.7 V.
- Keywords
- Antimony compounds; Carbon dioxide; Cobalt compounds; Electrocatalysts; Energy efficiency; Hydrogen production; Ion exchange; Ion exchange membranes; Ions; Oxygen evolution reaction; X ray absorption spectroscopy; Adsorption energies; Anion exchange membrane; Bond formation; H2 production; In-situ X-ray absorption spectroscopy; Overpotential; Oxygen evolution reaction (oer); Water splitting; Oxygen vacancies
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/105167
- DOI
- 10.1021/acsenergylett.0c02359
- ISSN
- 2380-8195
- Article Type
- Article
- Citation
- ACS ENERGY LETTERS, vol. 6, no. 2, page. 364 - 370, 2021-02-12
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