Mechanistic insights and design strategies for Ni-TM dual-atom catalysts on MXene for enhanced catalytic performance

The oxygen reduction/evolution reactions (ORR/OER) at the cathode of rechargeable metal-air batteries are key factors influencing energy efficiency and cycle life, but they face intrinsic challenges such as high overpotential and kinetic sluggishness. Single atom catalysts (SACs), with their high atomic utilization and defined active sites, have become a research hotspot. However, optimizing intermediate adsorption energies across multiple steps with a single metal site limits their catalytic performance. To overcome this, introducing dual-metal sites in MXene-based catalysts hold the potential to break the linear scaling relationship, though it also expands the space of co-adsorption intermediate configurations, with bridging and terminal binding making the dynamic surface changes complex to capture. Thus, systematically analysing the adsorption structure, electronic evolution, and energy dissipation paths of ORR/OER intermediates in a dual-metal synergistic environment is crucial for uncovering the intrinsic catalytic mechanism of MXene-based dual-atom catalysts (DACs) and guiding the design of next-generation catalysts. This study computes various adsorption scenarios of oxygen-containing intermediates on Ni-TM@Ti₂CO₂ (TM = Sc, Ti, V, Cr, Mn and Ni) catalysts, identifying stable adsorption configurations and providing new insights into the cooperative control of intermediate adsorption in DACs.