Water Oxidation-Induced Surface Reconstruction and Dissolution at the RuO2(110) Surface Revealed by First-Principles Simulation

The lack of atomic-scale understanding of the dissolution of RuO2 electrocatalysts for water splitting has hindered the development of durable RuO2-based electrocatalysts. In this study, using the first-principles electrochemical nudged elastic band method, we have discovered a facile water oxidation-induced Ru reconstruction and dissolution mechanism at the RuO2(110) surface. The potential-dependent activation energies of the dissolution process are well below 1.0 eV at electrode potentials higher than 1.5 V vs SHE. Furthermore, the Ru atoms in the close neighborhood of a Ru vacancy are found to be less prone to dissolution due to their higher oxidation state that could reduce the driving force for water oxidation-induced Ru reconstruction. These findings not only deepen the atomic-scale understandings of the Ru dissolution process but also provide routes for improving the stability of RuO2-based water splitting electrocatalysts.