Nanoporous Metal Oxide Catalysts by Hard-Template Method with Concurrent Improvement of Activity and Stability for Water Oxidation Reaction

Abstract

As the renewable energy generation increases, the storage of cut-tail electricity is becoming an important challenge due to the instability of photovoltaic and wind generation. Among the many approaches, the water electrolysis (WE) using proton exchange membrane (PEM) has been attracted great attention because of possibility of load-following and high current operations compared to the alkaline WE technology. For the PEMWE, the development of a catalyst towards water oxidation reaction (WOR) is highly demanded to secure the efficiency of the PEMFWE. In this study, the nanoporous metal oxide catalysts based on the Ir and Ru, which is prepared via the hard-template method, , which is representative elements for the PEMWE are prepared via a hard-template method using 2-dimensional (2D) and 3-dimensional (3D) mesoporous silica materials and investigated to improve the activity and stability simultaneously. The prepared nanoporous metal oxide showed a high specific surface area over than 100 m2/g regardless of composition, which is depend on the template. The transmission electron microscopy confirms the meso-porosity inside the metal oxide catalyst. For example, binary IrRuOx catalysts showed a small overpotential of 0.26V at 10mA/cm2 for oxygen evolution reaction, which indicates that the nanoporous catalysts increased the activity compared to the bulk oxides.