Sodium tungsten bronze-supported Pt electrocatalysts for the high-performance hydrogen evolution reaction

Abstract

Based on the strong metal–support interaction, designing and constructing metal–support catalysts is an effective strategy to achieve unique electronic structures and modulate interface microenvironments for improving hydrogen evolution reaction (HER) performance. Herein, sodium tungsten bronze (Na_xWO₃) nanotube bundles as a support are rationally fabricated on a stainless mesh (SM) through a simple hydrothermal method. Then, Pt nanoparticles with a low load-level (1.44%) anchored on the support are successfully developed to establish Pt–sodium tungsten bronze hybrid electrocatalysts. Impressively, the optimal electrocatalyst Pt/R-Na_xWO₃@SM-170 manifests excellent catalytic performance with extremely low overpotentials of 20 and 46 mV at −10 and −100 mA cm⁻² for the HER in 0.5 M H₂SO₄ solution, an ultralow Tafel slope of 18.6 mV dec⁻¹, and long-term stability, which is even superior to the benchmark Pt/C catalyst at high current density (69 mV at −100 mA cm⁻²). Additionally, the low overpotential is comparable to those of most previously reported Pt-based electrocatalysts. Meanwhile, it displays a mass activity of 2.27 A mg_Pt⁻¹ at an overpotential of 20 mV, 10.8 times higher than that of Pt/C (0.21 A mg_Pt⁻¹). Experiments and theoretical calculations demonstrate that the electron interactions between Pt and R-Na_xWO₃ synergistically lower the intermediate energy barrier and thereby maximize the activity of the Pt/R-Na_xWO₃@SM-170 electrocatalyst. This work introduces a reliable method to fabricate sodium tungsten bronze for use as a feasible support.