Electron transfer induced ruthenium-oxygen bond compression via d-band Center tailoring for efficient acidic overall...

Ruthenium-based materials are recognized as theoretically ideal bifunctional catalysts for acidic overall water splitting. However, their practical implementation remains constrained by critical challenges, such as the dissolution and over-oxidation of active sites under operating conditions. In this study, through precise modulation of the electronic structure at the Ru-RuO₂ heterojunction interface without incorporating any foreign metal elements, we successfully constructed a unique configuration characterized by compressed RuO bonds. Combined experimental characterization and theoretical calculations reveal that interfacial electron transfer induces the compression of RuO bond lengths, which subsequently leads to a downshift of the d-band center compared to pure RuO₂. This electronic modulation effectively optimizes the adsorption behavior of both oxygen and hydrogen intermediates, thereby simultaneously lowering the energy barriers for the oxygen evolution reaction and the hydrogen evolution reaction. The synthesized Ru-RuO₂@NC catalyst shows impressive bifunctional performance in an acidic electrolyte environment, reaching overpotentials as low as 161 mV for the oxygen evolution reaction and 53 mV for the hydrogen evolution reaction at a current density of 10 mA cm^-2. Additionally, it demonstrates outstanding durability, sustaining stable performance for more than 420 h at 10 mA cm^-2 during oxygen evolution reaction (OER) and 160 h even at a high current density of 500 mA cm^-2 for the hydrogen evolution reaction (HER). This research offers fresh theoretical perspectives and a methodological framework aimed at realizing efficient and stable acidic overall water splitting by means of interface bond manipulation.