Crystallographic insights into tetrahedral coordination for advanced electrocatalysis

This is the authors' abstract. We don't add key points for this paper.

Crystallography governs electrocatalysis because coordination geometry, lattice symmetry, and defect order set adsorption energetics, transport pathways, and structural resilience. Conventional descriptor strategies often fail once catalysts reconstruct and mixed coordination environments emerge, leaving the role of tetrahedral sites only partially resolved. This review advances a crystallography centered framework that treats tetrahedral coordination as an organizing principle across materials, structure, and function. The analysis formalizes key descriptors, including crystal field ordering, metal-anion covalency, multi site geometric coupling, vacancy channel topology, and polyanion stabilization. Four material families are mapped against these descriptors, namely spinel oxides, brownmillerite oxides, polyanion oxysalts, and metal sulfides, and their implications are traced across water electrolysis, oxygen and nitrogen reduction, carbon based conversions, and small molecule oxidation or reduction. The perspective converts scattered observations into transferable guidance, identifies tetrahedral architectures with significant headroom for activity and durability, and outlines synthesis and operando targets aligned with crystallographic control. The resulting blueprint enables predictive catalyst discovery and supports device level integration where adaptive lattices and controlled reconstruction are essential.