Insight Into the Roles of La 2 O 2 CO 3 ‐Based Catalysts in Heterogeneous Catalysis

Lanthanum oxycarbonate (La 2 O 2 CO 3 ) has attracted increasing attention in heterogeneous catalysis owing to its tunable surface basicity, morphology, carbonate chemistry and metal‐support interactions. Recent progress in La 2 O 2 CO 3 ‐based catalysts for CO 2 methanation, dry reforming of methane (DRM), oxidative coupling of methane (OCM), condensation reactions and selective hydrogenation is systematically reviewed, with emphasis on the roles of surface basic sites, carbonate species and morphology‐dependent interfaces, as well as the dynamic transformation between La 2 O 3 and La 2 O 2 CO 3 . These features influence reactant activation, reaction pathways, product selectivity, stabilization of supported metal species and carbon removal. La 2 O 2 CO 3 may therefore serve as a complementary material to conventional oxide supports or, in specific catalytic systems, as an alternative support or interfacial component. This review distinguishes direct evidence for La 2 O 2 CO 3 from effects of other La‐containing phases and establishes a phase‐resolved, condition‐dependent structure‐function framework to clarify its catalytic roles and guide rational La‐based catalyst design.