Pt single atoms on Cu nanowires facilitate anodic hydrogen production through efficient electrochemical formaldehyde oxidation

Abstract

The formaldehyde oxidation reaction (FOR) with ultra-low potential is an ideal alternative to the oxygen evolution reaction (OER), significantly reducing hydrogen production energy consumption. This reaction not only generates high-value formic acid but also releases H₂ at low potential, enhancing hydrogen production efficiency and economic viability. However, developing efficient and low-cost electrocatalysts remains a key challenge. In this study, a Pt single atom on Cu nanowire catalyst shows high catalytic activity for formaldehyde oxidation reaction (FOR). The catalyst achieves a current density of 100 mA cm⁻² at 0.09 V vs. RHE, with formic acid yield, selectivity, and formaldehyde conversion rate all close to 100 %. A bipolar hydrogen production system (FOR-HER) based on Pt_SA-Cu NWs and Pt/C assembly achieves a current density of 100 mA cm⁻² at a low cell voltage of 0.12 V, demonstrating a Faraday efficiency close to 100 % for H₂ at both the anode and cathode, and can stable operation for 30 h. Density functional theory (DFT) studies reveal that the interaction between Pt single atoms and Cu enhances hydrogen adsorption, significantly reducing the free energy of H* coupling and thereby improving hydrogen production efficiency. This study elucidates the intrinsic mechanism behind the enhanced performance, providing valuable guidance for the development of high-performance, low-cost single-atom catalysts.