Deciphering the Electronic Coupling Dynamics of Laser-induced Ru/Cu Electrocatalyst for Dual-Side Hydrogen Production and Formic Acid Co-synthesis via DFT Analysis

Abstract

Herein, a straightforward approach using pulsed laser technology to synthesize selective hexagonal-close-packed (hcp) Ru nanoparticles attached to Cu nanospheres (Ru/Cu) as bifunctional electrocatalyst for catalyzing the hydrogen evolution reaction (HER) and formaldehyde oxidation reaction (FOR) are reported. Initially, Ru-doped CuO flakes are synthesized using a coprecipitation method followed by transformation into Ru/Cu composites through a strategy involving pulsed laser irradiation in liquid. Specifically, the optimized Ru/Cu-4 composite not only demonstrates a low overpotential of 182 mV at 10 mA<middle dot>cm-2 for the HER but also an ultralow working potential of 0.078 V (versus reversible hydrogen electrode) for the FOR at the same current density. Remarkably, the FOR parallel to HER-coupled electrolyzer employing the Ru/Cu-4 parallel to Ru/Cu-4 system achieves H2 production at both electrodes with a cell voltage of 0.42 V at 10 mA<middle dot>cm-2 while co-synthesizing formic acid. Furthermore, density functional theory analyses elucidate that the superior activity of the Ru/Cu composite originates from optimized adsorption energies of reactive species on the catalyst surfaces during the HER and FOR, facilitated by the synergistic coupling between Ru and Cu. This study presents an alternative strategy for synthesizing highly effective electrocatalytic materials for use in energy-efficient H2 production with the cosynthesis of value-added chemicals suitable for practical applications. A straightforward pulsed laser technique is utilized to successfully convert Ru & horbar;CuO into a metallic Ru/Cu composite. Both experimental and theoretical analyses validated the dual functionality of the Ru/Cu composite in catalyzing the HER and FOR. The FOR parallel to HER-coupled electrolyzer using the Ru/Cu parallel to Ru/Cu system requires only 0.42 V at 10 mA<middle dot>cm-2 to achieve H2 production from both electrodes with formic acid co-synthesis. image