Probing the active site in single-atom oxygen reduction catalysts via operando X-ray and electrochemical spectroscopy.

ABSTRACT: Nonnoble metal catalysts are low-cost alternatives to Pt for the oxygen reduction reactions (ORRs), which have been studied for various applications in electrocatalytic systems. Among them, transition metal complexes, characterized by a redox-active single-metal-atom with biomimetic ligands, such as pyrolyzed cobalt-nitrogen-carbon (Co-N_x/C), have attracted considerable attention. Therefore, we reported the ORR mechanism of pyrolyzed Vitamin B12 using operando X-ray absorption spectroscopy coupled with electrochemical impedance spectroscopy, which enables operando monitoring of the oxygen binding site on the metal center. Our results revealed the preferential adsorption of oxygen at the Co²⁺ center, with end-on coordination forming a Co²⁺-oxo species. Furth

SUBMITTER: Lien HT 

PROVIDER: S-EPMC7447817 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature