Regulating electronic status of platinum nanoparticles by metal-organic frameworks for selective catalysis

Abstract

Selective hydrogenation of alkynes to alkenes remains challenging in the field of catalysis due to the ease of over-hydrogenated of alkynes to alkanes. Favorably, the incorporation of metal nanoparticles (MNPs) into metal-organic frameworks (MOFs) provides an opportunity to adjust the surface electronic properties of MNPs for selective hydrogenation of alkynes. Herein, we used different metal-O clusters of MOFs to regulate the electronic status of platinum nanoparticles (Pt NPs) toward overhydrogenation, semihydrogenation, and unhydrogenation of phenylacetylene. Specifically, Pt/Fe-O cluster-based MOFs are found to reduce the electronic density on Pt NPs and inhibit the overhydrogenation of styrene, leading to an 80% increase in selectivity toward a semihydrogenation product (styrene). Meanwhile, Cu-O cluster-based MOFs generate high oxidation states of Pt NPs and release Cu2+ ions, which worked together to deactivate Pt NPs in the hydrogenation reaction entirely. Thus, our studies illustrate the critical role of metal-O clusters in governing chemical environments within MOFs for the precise control of selective hydrogenation of alkynes, thereby, offering appealing opportunities for designing MNPs/MOFs catalysts to prompt a variety of reactions.