Magnetically Recyclable Cu-BTC@SiO₂@Fe₃O₄Catalysts and Their Catalytic Performance for the Pechmann Reaction

Abstract

Novel magnetic Cu-BTC@SiO 2 @Fe 3 O 4 catalysts were synthesized by encapsulating magnetic SiO 2 @Fe 3 O 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 2 adsorption/desorption, and NH 3 -temperature programed desorption (NH 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@SiO 2 @Fe 3 O 4 catalysts had the larger surface areas, suitable superparamagnetism, and good catalytic activity for Pechmann reaction. The conversion of 1-naphthol can reach ∼96%, and the selectivity of the production can reach ∼98% over 50.8% Cu-BTC@SiO 2 @Fe 3 O 4 (MCC-10) catalyst under the reaction conditions of 130 °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%.

Immunosensing of Atrazine with Antibody-Functionalized Cu-MOF Conducting Thin Films

“…The bands at around 930, 3440, and 3000–2500 cm –1 may have appeared due to the bending and stretching frequencies of the O–H group of ethanol (or absorbed water molecules). The FTIR spectrum of Cu 3 (BTC) 2 was in good agreement with the spectra in the reported literature. − The FTIR data for Cu 3 (BTC) 2 @SiO 2 were similar to those of Cu 3 (BTC) 2 , with an additional peak around 1100 cm –1 attributed to Si–O–Si stretching. − In the FTIR spectrum of antibody/Cu 3 (BTC) 2 @SiO 2 , the characteristic peaks of Cu 3 (BTC) 2 were largely masked, and instead a broad peak was observed at around 1640 cm –1 , which is characteristic of protein (antibody) amide bonds. − The appearance of an important Cu–O stretch peak at around 700 cm –1 demonstrates that the MOF structures with Cu and BTC molecules remained stable during the silica coating and antibody immobilization steps.…”

The First C−Cl Activation in Ullmann C−O Coupling by MOFs

“…N 2 adsorption‐desorption confirm a type IV isotherm that is in agreement with BJH measurement. The specific surface area was measured 125 m 2 /g which was found lower than the values reported for CuBTC (above 1000 m 2 /g) and equals the minimum values of γ ‐Fe 2 O 3 @SiO 2 ‐ filled CuBTC in literature (180 m 2 /g–850 m 2 /g). It seems that filling the pores of CuBTC by the amino‐functionalized maghemite sharply decreased the specific surface area of the whole structure.…”

Cation Exchange Superparamagnetic Al-Based Metal Organic Framework (Fe3O4/MIL-96(Al)) for High Efficient Removal of Pb(II) from Aqueous Solutions

“…Due to the embedding of Fe 3 O 4 nanoparticles in the crystalin structure of MIL-96­(Al), the obtained superparamagnetic Fe 3 O 4 /MIL-96­(Al) particles showed enough magnetism for facile separation from sample matrix by applying a magnetic field. As can be seen from Figure , the saturation magnetization was gradually decreased with increasing MOFs contents on the superparamagnetic nanoparticles. , The obtained values of saturation magnetization can be used to estimate the weight percentage (w/w %) of magnetic Fe 3 O 4 nanoparticles (Fe 3 O 4 %) and MOF contents (MIL96­(Al) %) in the particles of Fe 3 O 4 /MIL-96­(Al). Equations and were proposed for estimation of the composition of each nanoparticle: Whereas SM Fe 3 O 4 and SM Fe 3 O 4 /MIL‑96(Al) are saturation magnetizations of pure Fe 3 O 4 nanoparticles and Fe 3 O 4 /MIL-96­(Al) particles, respectively.…”