中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Modulation of dual centers on cobalt-molybdenum oxides featuring synergistic effect of intermediate activation and radical mediator for electrocatalytic urea splitting

文献类型:期刊论文

AuthorZhang, Kai; Liu, Chunlei; Graham, Nigel; Zhang, Gong; Yu, Wenzheng
SourceNANO ENERGY
Issued Date2021-09
Volume87Pages:-
KeywordCobalt-molybdenum oxide Synergistic effect Hydrogen evolution reaction Urea oxidation reaction Electrocatalysis
ISSN2211-2855
English AbstractConstruction of dual sites to break adsorption-energy scaling limitations offers an effective means of facilitating urea electrolysis for H-2 production, but a fundamental understanding of their synergistic mechanisms remains incomplete. Herein, we report a facile H-2 vapor-assisted strategy for the controllable fabrication of the bimetallic active Co2Mo3O8 electrocatalyst for alkaline urea splitting, with an applied voltage of only 1.50 V required to deliver 50 mA cm(-2). Direct spectroscopic evidence and theoretical investigation demonstrate that the Co sites are responsible for the activation of intermediates, whereas the assisting Mo centers are identified as the OH or H radical mediators. Specifically, the synergistic effect of the Co-Mo dual sites was conclusively verified by the insitu Raman and X-ray photoelectron spectroscopy. Theoretical calculations reveal that the short H-bonding (MoHO center dot center dot center dot H-NamineCO-Co) and Co-C-N-Mo configuration formed at the Co-Mo bridge are the key features determining a high reactivity for urea oxidation. The accelerated reaction rate is attributable to the conversion of the endoergic CO2 desorption to an exoergic reaction. In an alkaline H-2 evolution, Co atoms are the reaction sites for O-H bond cleavage of H2O, while Mo sites are considered to be the H-2-evolving centers. Determination of the individual functionality of synergistic dual centers represents a critical step towards the rational design of highlyefficient electrocatalysts.
WOS Research AreaChemistry, Physical ; Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Physics, Applied