Proton production in neutral electrolyte along oxygen evolution

Abstract

Proton production is imperative for many electrochemical reduction reactions, and the ability of an electrocatalyst to facilitate its production is vital for electrocatalysis. Herein commercial RuO2 is employed as our electrocatalyst for proton generation during oxygen evolution in a neutral electrolyte (0.2 M Na2SO4). The RuO2 catalyst achieves a low Tafel slope of 93 mV/dec and an overpotential of 570 mV at a current density of 10 mA cm−2. Its mass activity is calculated to be 12.37 A g−1. The Faradaic efficiency of proton generation (FEH+) is found to be 96.8%, 96.3%, 92.5%, 91.3%, and 90.8% at 1.8 V vs. RHE after 1, 3, 6, 9, and 12 h of electrolysis, respectively with a proton yield of 23.75%, 16.41%, 17.10%, 16.78%, and 20.89%, respectively. This study on facilitating proton production will greatly enhance efficiency across myriad energy conversion reactions. The acidified electrolyte can be reused in other applications.