Oxygen‐Deficient Ti0.9Nb0.1O2‐x as an Efficient Anodic Catalyst Support for PEM Water Electrolyzer

Abstract Herein, the low cost and efficient oxygen‐deficient Ti 0.9 Nb 0.1 O 2‐x as support of IrO 2 (noted as IrO 2 /TNO) anode catalyst for the PEM water electrolyzer is synthesized and then characterized using a series of techniques. Oxygen vacancies are introduced by hydrogenation treatment. The IrO 2 /TNO sample after hydrogenation (noted as IrO 2 /TNO−Hx, x corresponds to the hydrogenation temperature) exhibits enhanced electronic conductivity and increased surface active sites relative to that of the pristine IrO 2 /TNO sample. A single cell is assembled by IrO 2 /TNO−Hx as anode catalyst, commercial Pt/C as cathode catalytic and Nafion 117 membrane as electrolyte. At a low loading mass of IrO 2 , the IrO 2 /TNO−H750 sample shows the optimum oxygen evolution reaction (OER) activity (1.832 V at 1 A ⋅ cm −2 ), which is superior to that of unsupported IrO 2 (1.858 eV at 1 A ⋅ cm −2 ), and remains stable for 100 h operating at a current density of 1 A cm −2 . This work provides a rational design strategy for developing low cost and efficient anode catalysts support.