Predictive Models for Accelerating Biomimetic Electrocatalyst Discovery

Electrocatalytic reactions as underpinning to many renewable energy storage and utilization devices, such as fuel cells, electrolyzers, and metal-air batteries, involve multiple proton-coupled electron transfer steps. Arguably, for a given type of catalysts, e.g., molecular complexes, transition metals, and metal oxides or (oxy)hydroxides, the inherent scaling relations among the energetics of hydrogen-containing intermediates and transition states, inevitably limit the efficiency of energy conversion. We aim to develop a strategic framework to break the volcano limitations in electrocatalysis by harnessing confined solvation dynamics within nanoporous materials grafted with redox-active motifs. The inspiration of the proposed work comes from: 1) the deciding role of donor/acceptor coupling and solvent reorganization in charge transfer processes, and 2) the peculiar structural properties of supramolecular hydrogen-bonded networks under confinement. We engineer organic linkers and metal nodes of metal-organic frameworks (MOFs), thus the intrinsic adsorption properties of anchored iridium (Ir) complexes towards water oxidation intermediates and the external hydrogen-bonding interactions could be synergistically tailored such that the activation overpotential of the O-O bond formation is minimized without augmenting energy sinks/barriers of other steps. Using quantum chemical calculations and molecular dynamics simulations with advanced sampling techniques, we aim to, 1) unravel atomistic mechanisms of water oxidation at grafted Cp*Ir moieties; 2) develop predictive models for accelerating for organometallics-MOFs catalyst discovery; and 3) develop the ReaxFF repository/tools for assessing the stability of MOFs-based catalysts.