The influence of resorcinol on the kinetics of underpotentially deposited hydrogen, cathodic hydrogen and anodic oxygen evolution reactions, examined at polycrystalline Pt electrode in 0.1 M NaOH solution

This work presents ac. impedance spectroscopy and cyclic voltammetry electrochemical examinations on the influence of surface-adsorbed resorcinol (RC) or its oxidation/reduc-tion derivatives on the kinetics of underpotential deposition of hydrogen (UPD of H), cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER) processes, examined at polycrystalline Pt electrode in 0.1 M NaOH supporting electrolyte. The recorded data provided evidence on the beneficial role of Pt-electrosorbed resorcinol molecules on the kinetics of UPD of H. On the other hand, the effect of surface-adsorbed RC species (or its electro-oxidation intermediates) on the OER's kinetics was purely detri-mental, whereas the resorcinol effect on the cathodic HER was hardly discernible. The above was all elucidated through evaluation of the ac. Impedance-associated parameters and cyclic voltammetry profiles recorded for RC-free and resorcinol-modified NaOH electrolytes.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study investigates the influence of surface-adsorbed resorcinol and its oxidation/reduction derivatives on the kinetics of hydrogen deposition, hydrogen evolution reaction, and oxygen evolution reaction at a polycrystalline Pt electrode in 0.1 M NaOH electrolyte by using ac. impedance spectroscopy and cyclic voltammetry. The results show that Pt-electrosorbed resorcinol molecules have a positive effect on the kinetics of hydrogen deposition. However, surface-adsorbed resorcinol species or its electro-oxidation intermediates have a detrimental effect on the kinetics of oxygen evolution reaction, while the effect on cathodic hydrogen evolution reaction is barely noticeable. These conclusions are drawn through evaluation of ac. impedance-associated parameters and cyclic voltammetry profiles in RC-free and resorcinol-modified NaOH electrolytes.