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  • Surface Interrogation of Electrodeposited MnO x and CaMnO 3 Perovskites by Scanning Electrochemical Microscopy: Probing Active Sites and Kinetics for the Oxygen Evolution Reaction
Title: Surface Interrogation of Electrodeposited MnO x and CaMnO 3 Perovskites by Scanning Electrochemical Microscopy: Probing Active Sites and Kinetics for the Oxygen Evolution Reaction
Abstract Surface interrogation scanning electrochemical microscopy (SI‐SECM) of two electrodeposited manganese‐based electrocatalysts, amorphous MnOxand perovskite CaMnO3, was used to investigate the manganese oxidation state relating to the oxygen evolution reaction (OER) under neutral conditions. The results indicate the amounts of MnIIIand MnIVspecies in MnOxand CaMnO3depend on potential. A MnVspecies was identified in both structures during the OER. Time‐delay titration of MnVfurther revealed that MnOxproduced two types of active sites with different OER reaction rates:k′fast(MnOx)=1.21 s−1andk’slow(MnOx)=0.24 s−1. In contrast, CaMnO3perovskites in which the MnVspecies formed at a less positive potential than that in MnOx, displayed only one kinetic behavior with a faster reaction rate of 1.72 s−1.  more » « less
Award ID(s):
1707384
PAR ID:
10237020
Author(s) / Creator(s):
 ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Angewandte Chemie International Edition
Volume:
60
Issue:
2
ISSN:
1433-7851
Page Range / eLocation ID:
p. 794-799
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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