Doped TiO2-supported IrO2 electrocatalysts with high activity and durability toward the acidic oxygen evolution reaction

Abstract

The slow kinetic process of the oxygen evolution reaction (OER) and poor electrochemical stability in acidic environments of electrocatalysts seriously restrict the efficiency of hydrogen production from proton exchange membrane water electrolyzers (PEMWEs). In recent years, developing corrosion-resistant and redox-active doped TiO₂ with heterogeneous atoms has become an effective strategy to address this challenge. However, most of the reported studies only explore single-element doped TiO₂-supported catalysts, and there are few reports comparing the doping effects of various elements at the experimental level, which is crucial for screening high-performance OER electrocatalysts. In this work, seven different metal elements M (M = V, Mn, Fe, Ni, Cu, Nb, W) are selected for doping anatase TiO₂ with the same molar ratio (M/Ti) and combined with IrO₂ nanoparticles to form M-doped TiO₂-supported IrO₂ (M–TiO₂@IrO₂) electrocatalysts. Electrochemical OER activity and stability results indicate that W–TiO₂@IrO₂ exhibits the best performance among all these catalysts in terms of comprehensively regulating the conductivity of TiO₂ and the activity and stability of IrO_x within the range of experimental design in this work, which originates from the appropriate energy band structure obtained through W doping, optimizing the intrinsic conductivity of the support and interfacial electronic structure between the metal oxide and support.