Pd on composite chitosan bead containing a star-like hybrid metal-organic framework: A promising catalyst for hydrogenation of lubricants

Abstract

A star-like hybrid composite of metal-organic framework with amino-functionalized Fe-based metal-organic framework and zeolitic imidazolate framework components was synthesized, characterized and then embedded in chitosan beads. The beads were cross-linked with glutaraldehyde to furnish robust beads, which were then utilized as supporting materials for stabilizing Pd nanoparticles. The obtained catalytic composite was characterized via XRD, FTIR, TGA, ICP, SEM, EDS, elemental mapping and utilized for the hydrogenation of polyalphaolefin oil. The effects of temperature, catalyst loading and hydrogen pressure were investigated to find the best reaction conditions. According to the results, the present catalyst promoted hydrogenation reaction under relatively mild conditions (P = 8 bar, T = 130 °C and 5 wt% catalyst loading) to give the product in 98% yield and bromine index of 50 mg-Br/100 g. Besides, the catalyst exhibited acceptable recyclability and insignificant Pd leaching, which is very promising for large-scale applications. Hot filtration test also affirmed heterogeneous catalysis.