Ru-O Covalency Regulated via Constructing RuO2/Cr2O3 Heterogeneous Interface to Boosted Acidic Water Oxidation

Abstract

Developing efficient and durable oxygen evolution reaction (OER) catalysts under acidic conditions is crucial for green hydrogen production. Constructing heterogeneous interface structures represents the most promising strategy to overcome the intrinsic activity limitations of electrocatalysts. Here, the work prepares a crystalline-amorphous heterostructure catalyst (RuO2/Cr2O3) for enhanced performance in acidic OER, which achieves a low overpotential of 218 mV at 10 mA cm-2. X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) analysis indicate that the electron density of Ru is modulated by the interaction with Cr, leading to improved Ru-O bonding characteristics. The heterostructure effectively reduces the charge transfer resistance at the interface between crystalline and amorphous phases and facilitates the adsorption/desorption of OER intermediates. In situ Raman spectroscopy further reveals that the Ru-O bond interactions are significantly enhanced due to the regulation of the heterogeneous interface, which stabilizes Ru species dissolution at elevated potentials. Mass spectrometry analysis confirmed that lattice oxygen participation was inhibited, contributing to improvements in the durability of the OER, resulting in the stability of over 30 hours at 10 mA cm-2. This study presents a feasible strategy for the design and development of catalysts with enhanced activity and stability.