A Facile and In-situ Methanol-mediated Fabrication of Low Pd Loading, High-efficiency and Size-selectivity Pd@ZIF-8 Hydrogenation Catalyst

In-situ encapsulation of tiny and well-dispersed Pd nanoparticles (Pd NPs) in zeolitic imidazolate frameworks (ZIFs) was firstly achieved using a one-pot and facile methanol-mediated growth approach, in which methanol served as both solvent and a mild reductant. The microstructure, morphology, crystallinity, porosity as well as evolution process of the catalysts were determined by TEM, XRD, N-2 adsorption and UV-vis spectra. Due to the complete encapsulation of such Pd NPs combined with ultrahigh surface area and uniform microporous structure of ZIF-8, the resulting Pd@ZIF-8-60 min nanocomposite exhibited more superior catalytic activity for olefins hydrogenation with TOF of 7436 h(-1) and excellent size selectivity than previously reported catalysts. Furthermore, the catalyst displays excellent recyclability for 1-octene hydrogenation and without any loss of the Pd active species.