Titanium Oxide Nanosheets for Proton-Exchange Membrane Oxygen Evolution Electrocatalysts

Tuesday, 3 October 2017
Prince George's Exhibit Hall D/E (Gaylord National Resort and Convention Center)
R. Archer, F. Godinez-Salomon, and C. Rhodes (Texas State University)
Electrocatalysts used for the oxygen evolution reaction (OER) within the acidic environment of proton-exchange membrane (PEM) electrolyzers typically use precious metal oxides, IrOx and RuOx, which are extremely expensive and have a very limited supply. Approaches that can significantly reduce or eliminate the precious metal content of acidic OER catalysts and that provide high activity and stability are of significant interest. Toward this end, we have investigated using titanium dioxide nanosheets for acidic OER electrocatalysts. Expressing TiO2 within a nanosheet morphology allows expression of specific facets that may allow increasing the activity. Further, the OER activity may be enhanced through substitution of different transition metals within the structure to tune the surface electronic structure as well as increase the electronic conductivity. The TiO2 and substituted TiO2 nanosheets were prepared using solution-phase synthesis routes. The structure of the nanosheets was determined using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Raman spectroscopy. The OER activity and stability substituted TiO2 nanosheets were determined using a rotating disk electrode configuration and will be presented. The ability to create precious metal-free OER catalysts that provide high activity and stability provides the potential for significant reduction of the cost of PEM electrolyzers used for important applications including automotive hydrogen fueling stations and on-demand hydrogen production for industrial applications.