Research Center for Process and Prevention of Water Pollution

Dr. Xiaohui Yang published a technical paper “Sequential active-site switches in integrated Cu/Fe-TiO₂ for efficient electroreduction from nitrate into ammonia” in Applied Catalysis B: Environmental (IF: 24.3), DOI: https://doi.org/10.1016/j.apcatb.2023.122360. In this work, a novel sequential active-site-switching (SASS) mechanism was proposed according to the thermodynamic nature of bonding, which involves two key site switches on different active species in an integrated electrocatalyst. We implemented this concept by employing Cu/Fe hetero-phase-interface nanoparticles anchored in TiO₂ substrate (Cu/Fe-TiO₂) as a model platform. Theoretical calculations coupled with in situ infrared spectra confirmed the SASS mechanism: the *NO₃, preferentially adsorbed on the in-plane Fe phase, switches towards the Cu/Fe hetero-phase interface to reduce into *NH₃, and a further switch related to the *NH₃ occurs towards the in-plane Cu phase, notably facilitating the NO₃⁻-into-NH₃ conversion. This finding not only offers a novel perspective for exploring the NO₃⁻ RR mechanism and developing highly efficient catalysts but also opens up a window for the studies of other electrochemical redox reactions.