Unlocking Switchable Reactivity of MBene via Asymmetric Surface Adsorption.

The Sabatier principle and activity volcano have guided and constrained catalyst design. Surpassing these limitations requires going beyond the static view of catalysis. Here, we propose 2D metal boride (MBene) as a promising model system for dynamic catalysis, exemplified by the nitrogen reduction reaction (N2RR). The surface reactivity of B-rich MBene can be altered by binding organic ligands to the opposite side of the N2RR site. The change in reactivity originates in structural distortions of the metal and boron layers, leading to an energy span of up to 0.8 eV. By cycling the ligands or running a coupled reaction on the opposite side, we could switch between under- and overbinding energetics to surpass the Sabatier limit and access the inverse activity volcano. The reactivity space considering various metals and ligands can be efficiently explored by interpretable machine learning based on geometric descriptors, and promising ligand-bound MBenes for various catalytic scenarios are proposed.