118 The benecial interaction between Au and MnOx
smaller domains, oxidation features were observed already at 1.2 VRHE. The
XAS study therefore indicates that Mn oxidation state is not the critical parameter
and instead the properties of nearby Au sites could be more important.
Such a notion is in line with Au sites playing an active role in the reaction
mechanism such as suggested in the thermodynamics analysis. In conclusion,
the experimental ndings have shown important properties of the Mn-Au system,
which can guide further design into improved Mn based catalysts for OER.
More experiments are needed for a comprehensive understanding of the activity
enhancements.