Spherical Sandwich Au@Pd@UIO-67/Pt@UIO-n (n = 66, 67, 69) Core–Shell Catalysts: Zr-Based Metal–Organic Frameworks for Effectively Regulating the Reverse Water–Gas Shift Reaction

In this study, spherical sandwich Au@Pd@UIO-67/Pt@UIO-n (n = 66, 67, 69) core–shell catalysts were assembled. Au nanoparticles (NPs) were used as the core for the epitaxial growth of Pd shells, and Au@Pd core–shell NPs were successfully encapsulated in the center of monodispersed Au@Pd@UIO-67 nanospheres. Pt NPs were fully fixed onto the nanosphere surfaces to obtain Au@Pd@UIO-67/Pt composites; further coating with UIO-n led to Au@Pd@UIO-67/Pt@UIO-n, in which Pt NPs are sandwiched between the Au@Pd@UIO-67 core and the UIO-n shell. The Au@Pd core–shell NPs efficiently controlled the morphology and structure of UIO-67 and enhanced the CO selectivity of the catalyst. Pt NPs increased the CO2 conversion, and the UIO-n component effectively regulated the reverse water–gas shift reaction.