Altering Oxygen Adsorption Model on B-Doped Fe-Cu Dual-Atom Catalysts for Efficient Oxygen Reduction

Due to isolated active sites of single-atom catalysts (SACs), the catalytic kinetics of SACs are often unsatisfactory in those catalytic reaction processes involving multiple intermediates and reaction pathways, such as the oxygen reduction reaction (ORR). To address this bottleneck and enhance the ORR performance of SACs, we developed a boron-doped Fe-Cu dual-atom catalyst (Fe-Cu-B/NC). This catalyst is designed to modulate the oxygen adsorption model and adjust the adsorption strength of oxygen intermediates at the metal sites. In situ synchrotron infrared spectroscopy demonstrated that the Fe-Cu-B/NC catalyst facilitates the adsorption of oxygen intermediates on the Fe-Cu dual sites through a bridge adsorption model, which is more favorable for O & horbar;O bond cleavage. Meanwhile, in situ electrochemical impedance spectroscopy revealed that the transformation of the adsorption model can accelerate the kinetics of intermediate species, further enhancing the catalytic efficiency. As a result, Fe-Cu-B/NC exhibits good ORR activity and strong durability, retaining 90% of its initial current density after 10 h of the ORR process in alkaline media.