Local Ordering of Molten Salts at NiO Crystal Interfaces Promotes High‐Index Faceting

Given the strong influence of surface structure on reactivity heterogeneous catalysts, understanding mechanisms that control crystal morphology is an important component designing catalytic materials with targeted shape and functionality. Herein, we employ density functional theory to examine impact growth media NiO faceting in line experimental findings, showing molten-salt synthesis alkali chlorides (KCl, LiCl, NaCl) imposes selectivity particles. We find production octahedra attributed dissociative adsorption H2O, whereas formation trapezohedral particles associated kinetics exerted by ordered salt structures high-index facets. To our knowledge, this first observation inhibition metal-oxide facets occurs a localized ordering molten salts at crystal–solvent interface. These findings provide new molecular-level insight thermodynamics as predictive route shape-engineer crystals.