Development and Analysis on Structural Design of OER Catalyst for PEM Water Electrolysis Under High Current Density
Due to the acidic,high overpotential,and oxidizing environment,the commercial proton exchange membrane(PEM)water electrolysis usually requires very high loading of platinum group metals(PGMs)for the oxygen reduction reaction(OER)on the anode,without PGM-free metal catalysts available at present and leading to high costs.Alternatively,using high current density(HCD)to increase the power density is a feasible way to reduce the cost of PEM water electrolysis.However,with the current density increase,the water electrolysis overpotential also increases in an approximate linearship,which presents a big challenge for the charge and mass transfer.Therefore,the development of catalysts with high OER activity plays an important role in improving the efficiency of the PEM water electrolysis.This review introduced the compatibility of PEM water electrolysis with the renewable energy sources,and the fundamentals of OER catalyst development on the point view of the 4-e OER mechanism was revealed.Then the recent development of the OER catalysts was summarized from four aspects,including morphologies,surface structures,in-plane transfer capacity,and electrochemical reaction environment,and the reasons of their enhancement on transfer efficiency were analyzed.Finally,suggestions and insights on the trends of OER catalytic materials for PEM water electrolysis at high current densities were provided.
proton exchange membranehigh current densityoxygen evolution reactionanode catalytic materialstructure