We present our measurements of the oxygen electro-adsorption and oxygen evolution reaction (OER) on well-defined Ir1-xTixO2 and Ru1-xTixO2 surfaces. The slow OER kinetics contributes the largest source of overpotential (inefficiency) to water-splitting devices. An OER catalyst can reduce this overpotential by stabilizing the OER intermediates via surface electro-adsorption. We study the impact of the Ti addition on the OER kinetics of IrO2 and RuO2, two of the most active OER catalysts, in this work. To understand the influence of Ti, we also test how Ti impacts the electro-adsorption by quantifying the oxygen electro-adsorption on Ir1-xTixO2 and Ru1-xTixO2 as a function of Ti. Using the relationship between the Ti content, the oxygen electro-adsorption, and the OER kinetics, we present a physical model on how the Ti addition affects the OER kinetics in the context of the classical volcano plot. Finally, we discuss the mechanism on why the Ti addition can be beneficial and why sometimes not, and how to design a material to achieve the first outcome as a route to design future OER catalysts.

Well-defined surfaces show how Ti addition to IrO2 and RuO2 modifies oxygen electro-adsorption and oxygen evolution electrocatalysis

2019 Spring National Meeting

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