Magnetically Recyclable Cu-BTC[at]SiO sub(2)[at]Fe sub(3)O sub(4) Catalysts and Their Catalytic Performance for the Pechmann Reaction

Novel magnetic Cu-BTC[at]SiO sub(2)[at]Fe sub(3)O sub(4) catalysts were synthesized by encapsulating magnetic SiO sub(2)[at]Fe sub(3)O sub(4) nanoparticles into Cu-BTC through an in situ method. The structure of the catalysts was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, a vibration sample magnetometer (VSM), N sub(2) adsorption/desorption, and NH sub(3)-temperature programed desorption (NH sub(3)-TPD). The catalytic activity and recovery properties of the catalysts for the Pechmann reaction of 1-naphthol (NP) with ethyl acetoacetate (EAA) were evaluated. The results showed that the magnetic Cu-BTC[at]SiO sub(2)[at]Fe sub(3)O sub(4) catalysts had the larger surface areas, suitable superparamagnetism, and good catalytic activity for Pechmann reaction. The conversion of 1-naphthol can reach similar to 96%, and the selectivity of the production can reach similar to 98% over 50.8% Cu-BTC[at]SiO sub(2)[at]Fe sub(3)O sub(4) (MCC-10) catalyst under the reaction conditions of 130 degree C and 24 h. After the reaction, the catalyst can be easily separated from the reaction mixture by an external magnet. The recovery catalyst can be reused for five times, and the conversion of 1-naphthol can be kept over 90%.