Transition metal-doped two-dimensional TCNE as efficient bifunctional ORR/OER electrocatalysts: a first principles systematic screening study.

As the global climate crisis intensifies in tandem with escalating greenhouse gas emissions, the pursuit of sustainable energy technologies assumes paramount urgency. Electrochemical systems predicated on the bifunctional oxygen reduction and evolution reactions (ORR/OER) reside at the vanguard of clean energy conversion and storage technologies. Nevertheless, the rational design of substrate architectures that simultaneously confer high catalytic efficiency, long-term operational stability, and economic viability for cooperative ORR/OER catalysis persists as a formidable scientific challenge. Herein, a class of two-dimensional transition metal (TM)-doped TCNE frameworks (TM-TCNE) is rationally engineered, encompassing both parallel-stacked (TM-pTCNE) and perpendicularly aligned (TM-cTCNE) coordination structures. Through an exhaustive systematic screening protocol augmented by ab initio molecular dynamics (AIMD) simulations, Os-pTCNE, Ru-pTCNE, and Os-cTCNE are pinpointed as exceptional electrocatalytic platforms that exhibit robust and highly efficient bifunctional ORR/OER activity. Notably, the ORR and OER overpotentials on these optimized substrates are confined to values below 0.3 eV and 0.7 eV, respectively. First-principles calculations further elucidate the mechanistic origins of this cooperative electrocatalytic behavior, furnishing an atomistic-level elucidation of the electronic interaction pathways that underpin the observed performance. This study thus furnishes a rigorous theoretical foundation to guide the rational exploration and synthesis of advanced composite materials endowed with outstanding bifunctional electrocatalytic functionality.