How to Minimise Hydrogen Evolution on Carbon Based Materials?

In many electrochemical systems, such as carbon dioxide reduction, batteries and supercapacitors, hydrogen evolution reaction is an undesired competing reaction. Herein, we investigate the factors controlling the hydrogen evolution reaction (HER) on seven different commercial carbon materials commonly found in many of these systems. The electrochemical HER response was determined by rotating disk electrode potential hold measurements in acidic media, and correlated with the physical characteristics of the carbon materials determined nitrogen adsorption/desorption, as well as previous experiments on the same materials. An on-chip electrochemical mass spectrometer was used to probe the gaseous products produced at the electrode in situ, which allowed HER to be distinguished from other competing reaction and the onset of the reaction was established to be -0.38 V vs RHE. The results indicate that carbons with low amount of metal impurities have the lowest H-2 evolution rates.