Controlled Synthesis of Chromium-Oxide-Based Protective Layers on Pt: Influence of Layer Thickness on Selectivity

Chromium-oxyhydroxide (CrxOyHz)-based thin films have previously been shown in photocatalysis and industrial chlorate production to prevent unwanted reduction reactions occur, thereby enhancing the selectivity for hydrogen evolution thus overall process efficiency. Here, a highly reproducible synthesis protocol was developed allow electrodeposition of CrxOyHz-based with controlled thickness range sub-monolayer up (>4) multilayer coverage. Electrodeposited CrxOyHz coatings were electrochemically characterized using voltammetry stripping experiments, allowing thickness-dependent film be deduced detail. The results are discussed terms mass transport properties structure electrodeposited chromium oxyhydroxide films. It is that permeation diatomic probe molecules, such as O2 CO, significantly reduced by four monolayers. Importantly, it prepared enabled prolonged oxidation presence CO (up 5 vol.%), demonstrating benefits thin-film-protected electrocatalysts. In general, this study provides insight into use electrodes leading improvements (electro)catalyst durability.