Probing the Interface between Encapsulated Nanoparticles and Metal–Organic Frameworks for Catalytic Selectivity Control

Encapsulating metal nanoparticles (NPs) in metal–organic frameworks (MOFs) to control catalytic selectivity has recently attracted great attention; however, an understanding of the NP–MOF interface is lacking. In this work, we used spectroscopy to investigate the interfacial structure and then demonstrate its impact on selectivity. Metal NPs were encapsulated in MOFs using three approaches, impregnation, coating, and one-pot methods. Chemical interactions at the interface were probed through IR and Raman spectroscopy. The fine differences between the interfacial structures generated by the three methods affected their selectivity for the hydrogenation of crotonaldehyde. The direct interface generated by the one-pot method provides the highest selectivity toward the desired crotyl alcohol. This work provides a spectroscopic protocol to study hybrid interfaces and sheds light on their design for effective NP–MOF catalysts.