Electrooxidation of 2‐Propanol on Mono‐ and Bi‐Metallic Noble Metal Nanoparticles in Alkaline Studied with Real‐Time Product and Dissolution Characterization

Abstract The selective electrochemical oxidation of 2‐propanol to acetone can be used in fuel cells to deliver low‐carbon electricity and efficiently utilize hydrogen that is stored in liquid organic hydrogen carrier molecules. Here we study the electrooxidation of 2‐propanol in alkaline electrolyte, on various commercially available carbon‐supported mono‐ and bi‐metallic noble metal nanoparticles. We use voltammetry to compare the activity of different catalysts, and we combine a flow cell with real‐time analytics to monitor the products of the reaction and the dissolution of metal atoms in the presence and absence of 2‐propanol. While acetone if formed on all catalysts, our results show that the onset potential is the lowest for PtRu/C, Rh/C and PdRh/C, but the oxidation current for the latter reaches a much higher value before the surface is passivated, suggesting that PdRh/C would be preferred in an alkaline fuel cell that is fed with 2‐propanol. Online dissolution monitoring suggests that the anode in a 2‐propanol fuel cell should not be exposed to potentials above ca. +0.8 V during transient operation, i. e., during startup/shutdown conditions, to prevent dissolution of palladium and rhodium from the catalyst surface.