The extensive structural tunability of metal-organic frameworks (MOFs) positions them as exceptional candidates for engineering multifunctional electrocatalysts. Motivated by recent experimental advancements and guided by first-principles simulations, we introduce a new class of two-dimensional (2D) MOFs, TM 2 (TCNQ) 2 (TM = Cr, Mn, Fe, Co and Ni). These MOFs exhibit versatile and multifunctional catalytic activity for the hydrogen evolution (HER), oxygen evolution (OER), and oxygen reduction (ORR) reactions. Notably, in sharp contrast to the metal-centered activity observed in conventional TMN 4 catalysts, our findings reveal that the nonmetal site (specifically C) within the TCNQ linkers serve as the predominant active centers. This unique “ligand-centered” catalytic behavior is fundamentally rooted in the profound electronic coupling between the metallic centers and the π-conjugated organic components, which triggers a significant redistribution of electron density and local spin moments. Specifically, Mn 2 (TCNQ) 2 , Co 2 (TCNQ) 2 and Ni 2 (TCNQ) 2 monolayers serve as bifunctional catalysts for HER and OER, with overpotentials comparable to, or even surpassing, well-established noble-metal catalysts. These findings underscore the modular catalytic properties and the unconventional nonmetal-site-driven mechanism of the TM 2 (TCNQ) 2 architecture, providing a strategic route toward cost-efficient, versatile catalysts for sustainable energy technologies.
Lei et al. (Sun,) studied this question.