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Rational Design of Spinel Cobalt Vanadate Oxide Co 2 VO 4 for Superior Electrocatalysis.
- Source :
-
Advanced materials (Deerfield Beach, Fla.) [Adv Mater] 2020 Mar; Vol. 32 (10), pp. e1907168. Date of Electronic Publication: 2020 Jan 30. - Publication Year :
- 2020
-
Abstract
- Electrochemical energy devices, such as fuel cells and metal-air batteries, convert chemical energy directly into electricity without adverse environmental impact. Attractive alternatives to expensive noble metals used in these renewable energy technologies are earth-abundant transition metal oxides. However, they are often limited by catalytic and conductive capabilities. Here reported is a spinel oxide, Co <subscript>2</subscript> VO <subscript>4</subscript> , by marrying metallic vanadium atomic chains with electroactive cobalt cations for superior oxygen reduction reaction (ORR)-a key process for fuel cells, metal-air batteries, etc. The experimental and simulated electron energy-loss spectroscopy analyses reveal that Co <superscript>2+</superscript> cations at the octahedral sites take the low spin state with one e <subscript>g</subscript> electron ( t 2 g 6 e g 1 ) , favoring advantageous ORR energetics. Measurement of actual electrical conductivity confirms that Co <subscript>2</subscript> VO <subscript>4</subscript> has several orders of magnitude increase when compared with benchmark cobalt oxides. As a result, a zinc-air battery with new spinel cobalt vanadate oxide as the ORR catalyst shows excellent performance, together with a record-high discharge peak power density of 380 mW cm <superscript>-2</superscript> . Crucially, this is superior to state-of-the-art Pt/C-based device and is greatest among zinc-air batteries assembled with metal, metal oxide, and carbon catalysts. The findings present a new design strategy for highly active and conductive oxide materials for a wide range of electrocatalytic applications, including ORR, oxygen evolution, and hydrogen evolution reactions.<br /> (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Details
- Language :
- English
- ISSN :
- 1521-4095
- Volume :
- 32
- Issue :
- 10
- Database :
- MEDLINE
- Journal :
- Advanced materials (Deerfield Beach, Fla.)
- Publication Type :
- Academic Journal
- Accession number :
- 31999016
- Full Text :
- https://doi.org/10.1002/adma.201907168