Electrochemical trapping of metastable Mn³⁺ ions for activation of MnO₂ oxygen evolution catalysts.

ABSTRACT: Electrodeposited manganese oxide films are promising catalysts for promoting the oxygen evolution reaction (OER), especially in acidic solutions. The activity of these catalysts is known to be enhanced by the introduction of Mn³⁺ We present in situ electrochemical and X-ray absorption spectroscopic studies, which reveal that Mn³⁺ may be introduced into MnO₂ by an electrochemically induced comproportionation reaction with Mn²⁺ and that Mn³⁺ persists in OER active films. Extended X-ray absorption fine structure (EXAFS) spectra of the Mn³⁺-activated films indicate a decrease in the Mn-O coordination number, and Raman microspectroscopy reveals the presence of distorted Mn-O environments. Computational studies show that Mn³⁺

SUBMITTER: Morgan Chan Z 

PROVIDER: S-EPMC6003334 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature