Synergistic electronic structure modulation of Pt using V2O3 and V8C7 for enhanced deuterium evolution performance

Abstract

The slower kinetics of the deuterium evolution reaction (DER) than the hydrogen evolution reaction (HER) renders conventional Pt-based HER catalysts inefficient in the DER. Their further improvement requires precise tuning of intermediate adsorption energy which is already near optimum on pure Pt. Herein, we achieved superior DER/HER performance by combining Pt and a dual support system consisting of V₂O₃ and V₈C₇ that exert different electronic effects on Pt. In 1 M NaOD (NaOH) and 0.5 M D₂SO₄ (H₂SO₄), the optimal Pt/V₂O₃/V₈C₇ catalyst exhibited low overpotentials of 37 mV (15 mV) and 49 mV (45 mV) at a current density of 10 mA cm⁻², respectively. Its mass activity based on the amount of Pt was up to 9 times higher than that of commercial Pt/C, leading to a reduction of cell voltage by 0.5 V in PEM electrolysis of D₂O at 1000 mA cm⁻². X-ray photoelectron spectroscopy and underpotential H deposition showed that electron-withdrawing effects of V₂O₃ over-weakened intermediate adsorption on Pt/V₂O₃ while Pt/V₈C₇ had insufficient metal–support interaction of such kind. A balanced effect was only achieved with the dual support system, which accounts for the excellent performance of Pt/V₂O₃/V₈C₇. This study provides a new perspective on the modulation of metal–support interaction in Pt-based electrocatalysts and demonstrates potential application of the Pt/V₂O₃/V₈C₇ in industrial production of D₂.