Titania doped by niobium was successfully synthesized via a modified evaporation-induced self-assembly method (EISA) as a support of IrO 2 for a solid polymer electrolyte water electrolyzer (SPEWE). The doping amount of niobium (5, 10, 20 at. %) was emphatically investigated to evaluate the effects on nanostructure, morphology, and oxygen evolution reaction (OER) activity of Nb-doped titania supported IrO 2. The high-resolution transmission electron microscopy (TEM) results show that IrO 2 supported by Nbdoped titania exhibits grain refinement and uniform dispersion. An investigation of the electrocatalytic activity by half-cell electrochemical testing reveals that the Nb-doped titania supported IrO 2 catalyst demonstrates significant OER activity. When the Nb content reaches 20 at. % in the support, the Nb-doped titania supported IrO 2 possesses the highest OER activity, which is superior to that of pristine titania supported IrO 2 and unsupported IrO 2 . The single-cell tests also prove that 20 at. % is the best Nb doping amount for titania supports of IrO 2 . It is found that the majority of the OER activity increase is due to the Nb-doping induced enhancement of the specific surface area and surface activity of transferring charge and species. The additional specific surface area and redox couples of Nb(IV)/Nb(V) are also responsible for this performance enhancement. Herein, the as-synthesized Nb-doped titania is considered to be a promising oxygen evolution catalyst support for SPEWE applications.

TiO 2 doped tantalum was successfully synthesized via an evaporation-induced self-assembly method (EISA) as a support of IrO 2 for a solid polymer electrolyte water electrolyzer (SPEWE). The IrO 2 was synthesized on the surface of Ta-doped TiO 2 support by using the Adams fusion method. The samples were characterized by BET, XRD, SEM, TEM, CV, EIS and polarization curves of single cells. The doping amount of Tantalum (5, 10, 20, 30 at%) was thoroughly investigated to evaluate the effects on structure, electric conductivity and oxygen evolution reaction (OER) activity of Ta-doped titania supported IrO 2 . The results indicated that a significant effect of the Ta dopant on the phase composition and conductivity. Among all the catalysts, with the optimized catalyst IrO 2 loading, the terminal applied potential was 1.849 V at 1000 mA cm À2 and 80 C in a SPE water electrolysis cell using 80IrO 2 /Ti 0.

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Herein, the low cost and efficient oxygen‐deficient Ti0.9Nb0.1O2‐x as support of IrO2 (noted as IrO2/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 IrO2/TNO sample after hydrogenation (noted as IrO2/TNO−Hx, x corresponds to the hydrogenation temperature) exhibits enhanced electronic conductivity and increased surface active sites relative to that of the pristine IrO2/TNO sample. A single cell is assembled by IrO2/TNO−Hx as anode catalyst, commercial Pt/C as cathode catalytic and Nafion 117 membrane as electrolyte. At a low loading mass of IrO2, the IrO2/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 IrO2 (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.

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