DFT insights into synergistic interactions and ORR mechanisms of BN-supported dual-atom catalysts

The intrinsically slow kinetics of the oxygen reduction reaction (ORR) remains a major hurdle to the practical use of fuel cells. In this regard, we conducted a systematic theoretical exploration of ten dual-atom transition metal catalysts (Fe, Co, Ni, and Cu) supported on defective boron nitride to clarify the structure-activity relationship governing ORR performance. The evaluation of formation energies, stability, electronic structure, and catalytic properties indicates that dual-metal incorporation efficiently narrows the band gap of pristine BN and adjusts the d-band center, optimizing the adsorption and activation of oxygenated intermediates. Among the investigated catalysts, 2Cu-BN, CoCu-BN, and CuNi-BN have the lowest theoretical overpotentials of 0.64 V, 0.67 V, and 0.70 V, respectively. The 2Cu-BN catalyst exhibits a stable end-bridge adsorption configuration of O₂, and the CoCu-BN and CuNi-BN catalysts show stable end-on adsorption configurations of O₂ on top of cobalt and nickel centers, respectively. For the majority of the systems, the potential-determining step (PDS) is the transition of ∗OH → H₂O, but the 2Cu-BN catalyst exhibits an alternate path with ∗O₂ → ∗OOH as the PDS. Scaling relations and volcano plot analyses also confirm ΔG_∗OH as a reliable descriptor of the ORR activity. Overall, these findings highlight the potential of 2D-BN-supported dual-atom catalysts as a promising next-generation fuel cell alternative that can substitute platinum efficiently and cost-effectively.