Enhancement of the oxygen evolution reaction in Ru based electrocatalysts by modification of electronic structure

Abstract

Clean energy is attracting attention as a solution to the problems that cased by current energy economy system based on fossil fuels. In that point, the hydrogen resources produced by the electrochemical water splitting has merits in high energy density, no pollutions for operations and so forth. There are 2-electrochemical reactions occurs on the electrochemical water splitting system; hydrogen evolution reaction (HER) on cathode and oxygen evolution reaction (OER) on anode. Especially, Large overpotential with anode impedes overall water splitting efficiency. Although it is known that Ruthenium(Ru) element can achieve high performance, there is a problem of dissolution in the reaction. To address that issue, We focused on modification of the electronic structure of Ru based electrocatalysts by introducing platinum (Pt) as bimetallic electrocatalysts. That can be interpreted with modification of RuO6 coordination system about D2h compressed octahedral ligand field of Ru and oxygen. Especially PtO2 is structurally similar to RuO2, however different with electron occupancy in d-orbital. Those points are new approaches to modification of electronic structure but not changed dramatically on structural points. As a result of designing of catalysts system, enhanced activity can be interpreted. It can be proved by analyzing the results of XAFS, XPS and XRD. The electrochemical properties were measured in acidic condition using potentiostat.