Tuning catalytic performance in ethane hehydrogenation: Metal dimer composition effects on N-doped graphene-supported dual-atom catalysts

Ethylene production via ethane direct dehydrogenation (EDH) is hindered by catalyst deactivation due to coke formation from deep dehydrogenation and C–C bond cleavage. Dual-atom catalysts (DACs) anchored on N-doped graphene (M₁M₂-NC) offer tunable active sites to address this challenge. Combining DFT calculations, AIMD and kMC simulations, this work systematically explores EDH mechanisms across 15 types of M₁M₂-NC catalysts to obtain the most suitable combination of diatomic metal under realistic conditions. The results indicate that CH_x* species is identified as coke precursors, enabling a simplified reaction pathway to accelerate catalyst screening; RuCo-NC is screened out to outperform industrial Pt₃Sn and monometallic Pt under realistic conditions (873.15 K, 0.2 bar C₂H₆) with the optimal catalytic performance; A volcano-type correlation emerges between C₂H₄ production rate and C₂H₅* binding strength, establishing the latter as an effective activity descriptor. This multiscale computational framework provides atomic-level guidelines for rational design of coke-resistant EDH catalysts.