Preparation of Ir/TiO2 Composite Oxygen Evolution Catalyst and Load Analysis as Anode Catalyst Layer of Proton Exchange Membrane Water Electrolyzer

Abstract

Electrochemical water splitting is regarded as an emerging green and sustainable hydrogen production technology because of its zero-carbon process. However, the overall cost of anode materials in a proton exchange membrane water electrolyzer (PEMWE) is high due to the use of noble metal Ir. It has been proved that introducing carrier materials to reduce the content of Ir element is a feasible cost-reduction program. Here, the Ir/TiO₂ composite material was prepared by the polyol method and used to catalyze the oxygen evolution reaction, which could effectively reduce the load amount of Ir in the membrane electrode assembly (MEA). In addition, the theoretical load of Ir was obtained by model calculation and the polarization curve test and electrochemical impedance spectroscopy (EIS) were used to discuss the relationship between Ir load in MEA and voltage loss and conductivity. The results show that MEA has lower voltage loss and better conductivity as the Ir load is in the range of 0.204–0.304 mg_Ir/cm². Altogether, an effective method to reduce the Ir load of PEMWE anode was proposed under the premise comprehensive consideration of both catalyst design and MEA preparation in this work.