Hydrogen evolution reaction by sulphated zirconia:silica mixed oxides

The hydrogen evolution reaction is a critical half-reaction in the process of electrochemical water splitting. Nonetheless, this reaction frequently exhibits sluggish kinetics when non-platinum catalysts are employed. Given the prohibitive cost of platinum, it is imperative to explore and develop efficient non-platinum-based electrocatalysts to ensure sustainability in this field. In this work, SZr: SiO 2 mixed oxides were used as possible alternatives to platinum as hydrogen evolution reaction (HER) catalysts. The synthesized materials were characterized using scanning electron microscopy (SEM), X-ray diffratiometry, and Fourier transform infrared (FTIR). The electrochemical studies were conducted using cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA). Graphite electrodes (GE) were modified with SZr and with varying proportions of SZr: SiO 2 metal oxides. Among these modifications, the graphite-SPEEK/SZr: SiO 2 (1:2) electrode demonstrated superior performance, exhibiting a hydrogen evolution current density of 1300 mA/cm² at −2.2 V vs. RHE and an overpotential of −0.62 V vs. RHE at −10 mA/cm 2 based on the electrode geometrical dimension estimation.