Engineering Electrocatalytic Structures Through Molten Salt‐Mediated Mechanistic Control

ABSTRACT Molten salt synthesis has emerged as a versatile platform for the structural engineering of electrocatalysts, offering distinct advantages in controlling phase composition, morphology, and defect chemistry under thermodynamically and kinetically favorable conditions. However, critical challenges remain in elucidating the underlying mechanisms of molten salt‐mediated transformations, particularly regarding the influence of salt composition, redox activity, and thermal behavior on structural evolution and catalytic properties. This review provides a materials‐centered analysis of molten salt synthesis, emphasizing its structural modulation capabilities relative to conventional approaches. It systematically discusses six major classes of electrocatalysts: carbon‐based materials, metals and alloys, metal oxides, metal carbides and nitrides, metal sulfides and phosphides, and hybrid composites. The unique advantages of molten salt environments are highlighted in enabling controlled nanoscale architecture, tunable porosity, precise crystallographic orientation, and effective surface/interface engineering. These features facilitate the formation of metastable phases, high‐index facets, hierarchical porosity, and active defect sites, collectively enhancing charge transfer, active site exposure, and durability of catalysts. By correlating molten salt‐induced structural features with improved performance in water splitting, oxygen reduction, and carbon dioxide reduction, this review establishes a unified framework for catalyst design and offers mechanistic insights to guide future development of high‐efficiency electrocatalysts via molten salt strategies.