Optimizing Interfacial Hydroxyl Adsorption on the Ordered Ru-Sn Intermetallic for Efficient Hydrogen Evolution

Abstract

Ruthenium (Ru)-based electrocatalysts have garnered considerable attention due to their low water dissociation barrier, exceptional H adsorption strength and relatively lower cost in platinum-group metals catalysts. while the strong oxyphilic property of Ru leads to excessive adsorption of hydroxyl species (OHad) generated from the water dissociation process. However, it remains challenging to introduce another oxophilic species to weaken the adsorption of OHad while avoiding the coverage of active sites and ensuring the subsequent re-adsorption and desorption of water. Herein, we reported an ordered Ru3Sn7 intermetallic compounds (IMCs)/acetylene black (AB) electrocatalyst. The highly ordered structure exposed abundant Ru active sites and atomically adjacent Sn oxophilic sites enable uniform distribution of both H and OH adsorption sites and preventing the coverage of Ru site. The prepared Ru3Sn7 IMCs/AB promotes interfacial water adsorption/dissociation by optimizing OH adsorption ability. As a result, Ru3Sn7 IMCs/AB catalyst delivers exceptional HER performance, achieving a low overpotential of 9 mV at 10 mA cm-2 and long-term durability over 150 hours. CO-stripping tests, in situ electrochemical Raman spectroscopy and DFT calculations revealed that synthesized ordered Ru3Sn7 IMC effectively modulates the OH adsorption and improve the adsorption/desorption of interfacial water