The
development of stable and efficient electrocatalysts is of
key importance for the establishment of a sustainable society. The
activity of a metal electrocatalyst is determined by its electrochemically
active surface area and intrinsic activity, which can be increased
using highly porous structures and heteroatomic doping, respectively.
Herein, we propose a general strategy of generating mesopores and
residual oxygen in metal electrocatalysts by reduction of metastable
metal oxides using Ag2O3 electrodeposited onto
carbon paper as a model system and demonstrating that the obtained
multipurpose porous Ag electrocatalyst has high activity for the electroreduction
of O2 and CO2. The presence of mesopores and
residual oxygen is confirmed by electrochemical and spectroscopic
techniques, and quantum mechanical simulations prove the importance
of residual oxygen for electrocatalytic activity enhancement. Thus,
the adopted strategy is concluded to allow the synthesis of highly
active metal catalysts with controlled mesoporosity and residual oxygen
content.