Carbon-based active support for water oxidation electrocatalyst: Making full use of the available surface area

Abstract

Since the support of conventional electrocatalysts is mostly inert, certain parts of these supported electrocatalysts that have direct contact with the reactants do not have electrocatalytic function. Therefore, the surface area of these electrocatalysts is larger than their electrochemically active surface area. So as to make full use of the available surface area and release the activity potential of the electrocatalysts, this work synthesized a carbon-based active support with certain electrocatalytic activity for water oxidation reaction, providing a general route to prepare electrocatalysts with electrochemically active surface area close to their surface area. In detail, a cubic core-shell support was synthesized via an aqueous phase synthesis method for oxygen evolution reaction (OER). The carbon-based active support with a larger specific surface area (306 m2 g−1) is beneficial to the dispersion of the active sites. The support has appropriate OER catalytic activity which can synergistically catalyze OER together with NiFe (oxy)hydroxide on it during the reaction. Under the current density of 10 mA cm−2, the overpotential is as low as 214 mV for OER, which is better than those of most non-precious metal catalysts, suggesting that carbon-based active support could effectively reduce energy consumption via promoting surface area utilization ratio.