Dynamic Co(μ-O)_2Ru Moiety Endowed Efficiently Catalytic Hydrogen Evolution

摘要

A large number of highly active Ru-based electrocatalysts have been reportedfor the hydrogen evolution reaction (HER). The utilization of synergisticeffects for promoting HER performance remains inadequate, especially forcorresponding potential-driven reactive sites at the atomic level. Herein, aCo-substituted Ru-Ru2P structure is employed as a model system to revealthe synergistic effect on Ru-based electrocatalysts and to realize the potentialdrivenreactive sites during the HER. Optimized Ru-Ru2P @ Co0.6 exhibits asuperior catalytic performance in alkaline electrolytes, achieving a low overpotentialof 9 mV at a current density of 10 mA cm–2. To precisely describethe geometrical nature of surface moiety of Co(μ-O)_2Ru, an indicator (β) isestablished to quantify the strain of Co(μ-O)_2Ru moieties through calculatingthe L-Co-L (L = P or O) angles through employing in situ X-ray absorptionspectroscopy. Both bond strain and corresponding metal-metal distance ofCo-Ru in Co(μ-O)_2Ru moiety can significantly affect the structural toleranceand facilitate the coupling of adsorbed hydrogen atoms during HER. It isbelieved that the perspective raised in the present work will provide a newavenue to the design of highly active HER catalysts at the atomic scale.