Monodisperse Metal–Organic Framework Nanospheres with Encapsulated Core–Shell Nanoparticles Pt/Au@Pd@{Co₂(oba)₄(3-bpdh)₂}4H₂O for the Highly Selective Conversion of CO₂ to CO

A new microporous metal–organic framework (MOF) with formula {Co2(oba)4(3-bpdh)2}4H2O [oba = 4,4′-oxybis(benzoic acid); 3-bpdh = N,N′-bis-(1-pyridine-3-yl-ethylidene)-hydrazine] was assembled, and its morphology was found to undergo a microrod-to-nanosphere transformation with temperature variation. Core–shell Au@Pd functional nanoparticles (NPs) were successfully encapsulated in the center of the monodisperse nanospheres, and Pt NPs were well-dispersed and fully immobilized on the surface of Au@Pd@1Co to build the Pt/Au@Pd@1Co composites, which exhibited NPs catalytic activity for the reverse water gas shift reaction. The core–shell Au@Pd NPs in MOF significantly enchanced the CO selectivity of the catalyst, and the Pt NP loading on the surface of the nanosphere afforded a desirable CO2 conversion.