Morphology Control and Catalytic Dehydrogenation Performance of Zeolitic Imidazolate Frameworks-8北大核心CSCD

Zeolitic imidazolate frameworks-8（ZIF-8）is a kind of porous material with large specific surface area and strong stability，which is widely used in gas storage，separation，catalysis and other fields. In this work，the effect of different reaction conditions，such as the molar ratio of Zn2+ to 2-methylimidazole，the amount of surfactant and the reaction solvents，on the size and morphology of ZIF-8 were reported. Among these conditions，the molar ratio of Zn2+ to 2-methylimidazole is the key factor affecting the size and morphology of ZIF-8. The synthesized ZIF-8 nanoparticles were characterized by SEM，BET and XRD. The size of ZIF-8 decreases gradually from 1500 nm to 850 nm then to 250 nm，and the morphology changes from truncated hexahedron to truncated dodecahedron and finally to dodecahedron. The specific surface area of ZIF-8 nanoparticles with a particle size of 250 nm is 1730 m2/g，and the pore size and pore volume are 1. 5 nm and 0. 6 cm3/g，respectively. Therefore，it can be seen that ZIF-8 nanoparticles with a particle size of 250 nm have excellent carrier characteristics. The impregnation method was further adopted to synthesize the supported catalyst，and boron ammonia was used as the reducing agent. The ZIF-8（250 nm）nanoparticles were loaded with metals/precious metal nanoparticles in situ，the component optimization and catalytic performance were further studied. The obtained catalyst ZIF-8/Pt0. 002@Ni0. 2 shows excellent performance in hydrogen generation from aminoborane. © 2022, Science Press (China). All rights reserved.