Spontaneous Hydrogen Production Coupled with Glucose Valorization through Modulating Au-Pt Coordination on Ultrathin Au3Pt Twin Nanowires

Abstract

Organics electrooxidation coupled hydrogen production has attracted increasing attention due to the low operation voltage. Nevertheless, the spontaneous production of hydrogen coupled with organics valorization remains challenging. Herein, we develop ultrathin Au/Pt twin nanowire (NW) catalysts for both electrochemical glucose oxidation and hydrogen evolution reaction towards a spontaneous hydrogen production system. The more Pt-Au coordination and the localized tensile strain generated on twin boundaries of Au3Pt NWs facilitate the selective glucose electro-oxidation to gluconic acid (GNA) compared to Pt NWs (a low onset potential of 0.07 VRHE and selectivity > 90%). In-situ spectroscopy and theoretical calculations reveal that Au3Pt NWs could reduce the energy barriers for GNA generation and alleviate the poisoning of Pt sites via a 'Pt-to-Au site transfer' mechanism, which facilitates the desorption of strongly absorbed gluconolactone. Therefore, the asymmetric cell equipped with Au3Pt NW catalysts realizes the spontaneous hydrogen production and glucose valorization with a peak power of 50 mW, which outputs the voltage of 0.24 V at 50 mA cm-2, outperforming the state-of-the-art electrolyzers for hydrogen production. The production of 1 kg H2 of the device is accompanied with $64.2 valorization of the anode product ($1200 ton-1 for GNA), and 5.36 kW h of generated electricity.