Screening efficient Pt-based dual-metal atomic-level catalysts for the oxygen reduction reaction

Abstract

In this work, a computer-aided screening strategy combined with density functional theory (DFT) was employed to screen and identify high-performance Pt-based dual-atom catalysts PtM-L₆@Gra (M = 3d, 4d, 5d; L = N, C, B) for oxygen reduction reactions (ORRs). Comprehensive studies demonstrated that six representative electrocatalysts (i.e., PtCo-C₆@Gra, PtNi-C₆@Gra, PtZn-C₆@Gra, PtFe-N₆@Gra, PtCo-N₆@Gra, PtNi-N₆@Gra) showed high ORR catalytic activities under both acidic and basic conditions, with favorable overpotentials (among them, PtZn-C₆@Gra was the best candidate with the lowest η_ORR of 0.49 V). The ORR followed a 4-electron mechanism with the final products H₂O/OH⁻. PtFe-, PtCo-, and PtNi-N₆@Gra and PtCo-, PtNi-, and PtZn-C₆@Gra demonstrated superior activities with low η_ORR due to their moderate adsorption strength of *OH. More importantly, intrinsic physical quantities were used to construct various effective descriptors (such as (d_*(Pt–M) + χ_M) × ΔG_*→*O2, (d_*(Pt–M) + χ_M) × ΔG_{*OH→*+OH⁻}, (avg[d_a(Pt–M)] + χ_M) × ΔG_*→*O2 and (avg[d_a(Pt–M)] + χ_M) × ΔG_{*OH→*+OH⁻}) for rapid screening and identification of promising electrocatalysts, unveiling the mechanism, and establishing the structure–activity relationship. The present study provides an important route for developing efficient low-Pt catalysts for ORR and will inspire subsequent experimental and theoretical work in this direction.