Eco-friendly controllable synthesis of highly dispersed ZIF-8 embedded in porous Al2O3 and its hydrogenation properties after encapsulating Pt nanoparticles

Abstract In this paper, a new strategy was proposed to synthesize a novel composite of highly dispersed ZIF-8 embedded in porous Al2O3 by a solvent-free method. This is a very simple, efficient, and eco-friendly method, in which ZnO/Al2O3 was used as a precursor, and dimethyl imidazole was used as an organic ligand. Meso- and microporous composite of ZIF-8@Al2O3 was synthesized arising from the crystal growth of ZIF-8 derived from ZnO nanoparticles. Characterization results reveal that the distribution of micropores and mesopores can be controlled by simply adjusting the amount of zinc salt supported on Al2O3. The value of this composite is that it can simultaneously exert the advantages of ZIF-8 and Al2O3 support, which can significantly decrease the particle size of ZIF-8 and improve its utilization efficiency. The micropores of ZIF-8 can increase the dispersion of Pt nanoparticles, at the same time, the functional groups on the surface of Al2O3 can improve the selectivity of the product. Furthermore, this kind of composite material can be extended by replacing the support. Finally, the results of the activity tests showed that the obtained Pt/ZIF-8@Al2O3 catalyst exhibits high activity and selectivity in hydrodearomatization (HDA) and hydrodeoxygenation (HDO) reactions.