Niobium oxide on amphoteric supports: interface engineering for synergistic heterogeneous catalysis

Niobium pentoxide (Nb 2 O 5 ) is a versatile solid acid in heterogeneous catalysis, yet its potential is constrained by low surface area and domain aggregation in bulk phases. This Review critically analyzes the paradigm shift from unsupported Nb 2 O 5 to the engineering of nanostructured interfaces on amphoteric supports (Al 2 O 3 , ZrO 2 , TiO 2 , ZnO, and Metal Mixed Oxides). We examine how modulating Nb-O-M interfacial linkages stabilizes highly dispersed distorted sites that exhibit cooperative behavior inaccessible to isolated components. By establishing structure-interface-activity relationships, we demonstrate how this synergy directs superior performance across diverse transformations, from classical esterification and biomass valorization to advanced photocatalytic processes. We show that the support dictates the mechanistic character of this synergy, ranging from bifunctional acid pairing and lattice-stabilized proton pathways to redox-acid cooperativity, multifunctional acid-base tuning, and semiconductor heterojunction behavior. Finally, we delineate perspectives for designing multifunctional Nb-based architectures through atomic-level control to advance sustainable chemical processes.