Au@Pt Nanotubes within CoZn-Based Metal-Organic Framework for Highly Efficient Semi-hydrogenation of Acetylene.

Designing nanocatalysts with synergetic functional component is a desirable strategy to achieve both high activity and selectivity for industrially important hydrogenation reaction. Herein, we fabricated a core-shell hollow Au@Pt NTs@ZIFs (ZIF, zeolitic imidazolate framework; NT, nanotube) nanocomposite as highly efficient catalysts for semi-hydrogenation of acetylene. Hollow Au@Pt NTs were synthesized by epitaxial growth of Pt shell on Au nanorods followed with oxidative etching of Au@Pt nanorod. The obtained hollow Au@Pt NTs were then homogeneously encapsulated within ZIFs through in situ crystallization. By combining the high activity of bimetallic nanotube and gas enrichment property of porous metal-organic frameworks, hollow Au@Pt NT@ZIF catalyst was demonstrated to show superior catalytic performance for the semi-hydrogenation of acetylene, in terms of both selectivity and activity, over those of monometallic Au and solid bimetal nanorod@ZIF counterparts. This catalysts design idea is believed to be inspirable for the development of highly efficient nanocomposite catalysts.

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.

Monodispersed gold nanoparticles supported on a zirconium-based porous metal-organic framework and their high catalytic ability for the reverse water-gas shift reaction.

A highly active and selective Au@UIO-67 catalyst has been assembled. Gold nanoparticles (AuNPs) are monodispersed on the UIO-67 surface of a porous metal-organic framework, the micropores in UIO-67 as templates for adsorbing Au ions and enhancing interaction between AuNPs and UIO-67, favoring the formation of isolated and well-dispersed AuNPs. The catalyst exhibits high catalytic activity and CO selectivity for the reverse water-gas shift reaction in a fixed-bed flow reactor.