Synergistic modulation of nanostructure and active sites: Ternary Ru&Fe-WOx electrocatalyst for boosting concurrent generations of hydrogen and formate over 500 mA cm-2

Abstract Coupling methanol-to-formate oxidation (MFO) with hydrogen evolution reaction (HER) may promote hydrogen economics by introducing value-added anodic product. Herein, we develop a ternary catalyst Ru&Fe-WOx for boosting both HER and MFO in alkaline media. An electrode pair based on Ru&Fe-WOx delivers 10/100/500 mA/cm2 current density at a low cell-potential of 1.38/1.50/1.62 V with excellent durability and nearly 100 % Faradaic efficiency (FE), outperforming the benchmark pair of Pt/C||RuO2. By using integrated experimental and theoretical approaches, we verify synergy between WOx host and Ru&Fe-based dopants, which results in optimized H* adsorption on lattice oxygen (HER) as well as enhanced HCOO* desorption on ruthenium site (MFO). In addition, the unique nanostructure of Ru&Fe-WOx may further benefit to the mass transfer and catalyst robustness at large current density. This work thus demonstrates an integrated catalyst design, which is highly efficient for boosting concurrent, cost-effective and scalable production of hydrogen and formate.