Unveiling Surface Electronic Descriptors and Structure–Activity Relationships of Frustrated Lewis Pairs within Topologically Engineered M6O4(OH)4-Based MOFs for Hydrogenolysis

The rational design of frustrated Lewis pairs (FLPs) within metal–organic frameworks (MOFs) is crucial yet challenging for efficient hydrogenolysis reactions, primarily due to ambiguous structure–activity relationships and dynamic mechanisms. In this study, we employ typical MOFs featuring identical M₆O₄(OH)₄ metal clusters but distinct topologies as model systems to investigate the underlying mechanisms of hydrogenolysis. By integrating in situ infrared spectroscopy with electronic property analysis, we elucidate, for the first time, the modulation of the energy barrier through the kinetically decoupled formation of the Lewis acid (LA)–H and Lewis base (LB)–H bonds in FLPs. The influence of topology-dependent spatial configuration and metal type (Zr/Ce) on H₂ adsorption orientation and cleavage energy barriers is systematically explored using density functional theory (DFT) calculations alongside experimental characterization. The derived multivariate descriptor φ_CHELPG captures the electrostatic and spatial synergies among LA, LB, and proximal Brønsted acid (BA, μ₃–OH) sites, offers exceptional predictive power for hydrogenolysis performance across mono- and bimetallic MOFs. MOF-808(Zr)-D1 exhibits the lowest energy barrier, attributed to LB-dominated H₂ adsorption and retarded LB–H bond formation kinetics. This work paves the way for a transition from empirical screening to rational design in nonprecious metal hydrogenation systems.