Silver Nanoparticles Stabilized by Metal-Organic Framework (MIL-101(Cr)) as Efficient Catalyst for Imine Production from the Dehydrogenative Coupling of Alcohols and Amines
In this paper, we present silver nanoparticles supported on metal-organic framework (Ag@MIL-101) as a catalyst for the one-pot tandem synthesis of imines from alcohols and amines. Ag@MIL-101 catalyst was fabricated using the liquid phase impregnation technique as an easy and effective method. The morphology and chemical structure of the prepared catalyst was systemically evaluated by inductively coupled plasma optical emission spectroscopy (ICP-OES), powder X-ray diffraction (P-XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The highly crystalline feature of Ag metals on bifunctional MIL101(Cr) was revealed by TEM and HRTEM analyses. The Ag@MIL-101 catalyst was examined as catalyst for the synthesis of different imine derivatives. The catalytic performance of Ag@MIL-101 catalyst was monitored GC-MS and 1H-NMR analyses for the dehydrogenative coupling of alcohols and amines. Furthermore, the effect of various factors such as the amount of catalyst, base, temperature and solvent was investigated to optimize the conditions for the best performance of the Ag@MIL-101 catalyst. Catalytic activity results showed that Ag@MIL-101 catalyst has a good catalytic activity with the TOF values in the range of 12.7-14.6 h-1 in the synthesis of various imines.