Cross-Scale Process Intensification of Spindle CuO Supported Tungsten Single-Atom Catalysts toward Enhanced Electrochemical Hydrogen Production

Abstract

Process intensification engineering of electrocatalysts is crucial to facilitate electrocatalytic reaction, while its cross-scale modulation is of great challenge. Herein, the spindle CuO supported tungsten single-atom catalysts (W SACs) with tunable mesoscale electric field and atomic-scale coordination structure are reported toward enhanced electrochemical hydrogen evolution process. Finite element analysis indicates the mesoscale electric field can be enhanced by tailoring the tip angle of spindle configuration from 74° to 27°, enhancing hydrogen production rate by 5 times. Based on the density functional theory calculations, the configuration regulation also triggers the increase of coordination number of W–O, which increases charge transfer and downshifts d-band center, stabilizing W sites and optimizing hydrogen desorption process. The optimized WSA/CuO-27 exhibits much better hydrogen evolution activity (η100 = 94 mV) and stability (200 mA cm−2 for 120 h) than as-prepared WSA/CuO-56 and WSA/CuO-74 analogues. Impressively, the anion exchange membrane electrolyzer fabricated with the WSA/CuO-27 presents excellent activity comparable to that of commercial electrocatalysts, and also delivers an ultra-low attenuation of 0.085 mA cm−2 h−1 at 300 mA cm−2 after continuous electrocatalysis for 120 h. This work inspires the design of high-efficiency supported metal catalysts for electrochemical synthesis via the cross-scale process intensification engineering.