Investigation of Nanoporous Metal Oxide towards Oxygen Evolution Reaction

Abstract

As the electricity generation using sustainable resources such as sun, wind and water increase, the storage of excess electricity is becoming a big issue to address. Among the many approaches, the water electrolysis(WE) using protonexchange membrane(PEM) has been attracted great attention because of excellent load-following characteristics compared to the well-established alkaline WE technology and operation ability at high current density. For the PEMWE, the development of a catalyst towards oxygen evolution reaction (OER) is highly demanded to increase the total efficiency. In this study, the nanoporous metal oxide catalysts based on the Ir and Ru, which is representative composition for PEMWE are investigated to improve the activity and stability concurrently. The nano-template using 2-dimensional and 3-dimensional (3D) mesoporous silica materials is applied to prepare the nanoporous metal oxides with high surface area compared to the bulk oxides. For example, the electrochemically active surface area of 3D nanoporous RuO2 is measured as more than 100 m2/g. The over potential of nanoporous metal oxide at 10mA/cm2 is 0.29V, which is smaller than the bulk IrO2 and RuO2 catalyst. And the durability under 10mA/cm2 up to 1.58 V of this catalyst is estimated as more than 4 h, which implies the simultaneous enhancement of activity and durability for OER.