Synthesis of Ag/ZIF-67 nanocomposite and its catalytic activity for the reduction of various nitrobenzaldehyde isomers

Abstract The Ag/ZIF-67 nanocomposite was prepared by the reaction of cobalt nitrate hexahydrate (Co(NO 3 ) 2 · 6H 2 O) with 2-methylimidazole and silver nitrate (AgNO 3 ). The morphology and structure of Ag/ZIF-67 nanocomposite were investigated by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), Ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and Raman spectroscopy, which indicated that Ag/ZIF-67 composite was successfully synthesized with a rhombic dodecahedron structure. The catalytic activity of the hybrid nanocomposite (Ag/ZIF-67) was investigated toward the reduction of the nitro compounds (2-, 3-, and 4- nitrobenzaldehyde) to their corresponding amino compounds (2-, 3, and 4-aminobenzyl alcohol) in the presence of sodium borohydride (NaBH4) as a reducing agent. The rate for catalytic reduction of nitrobenzaldehyde isomers using Ag/ZIF-67 nanocomposite was in the order: 4-> 2- > 3- nitrobenzaldehyde. The kinetics study showed that the reduction of nitrobenzaldehyde isomers was followed by a pseudo-first-order reaction rate law.