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The paper reports the synthesis, surface and textural characterization of copper and amine modified MCM-41 and its application for the single step amination of benzene to aniline at 70 °C. Varying the amount of Cu different Cu/amine modified MCM-41 samples was synthesized by co-condensation and impregnation method. The samples were characterized by nitrogen adsorption–desorption, X-ray powder diffraction, Fourier-transform infrared spectroscopy (FT-IR), 29Si magic-angle spinning (MAS) and 13C Nuclear Magnetic Resonance (NMR) and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). X-ray diffraction patterns indicate that the modified materials retain the standard MCM-41 structure. FT-IR and DRS results indicated that Cu and amino groups are incorporated into the Si–O framework and frame wall respectively. NMR showed higher degree of condensation of materials in framework position. Cu-amine-MCM-41 samples showed significant catalytic activity for single step amination of benzene in acetic acid–water medium under mild reaction conditions using hydroxylamine as aminating agent. The Cu-amine-MCM-41 (Si/Cu = 20) showed highest benzene conversion (72.2%) and 100% selectivity for aniline.

This paper reports preparation, characterization of amine modified mesoporous crystalline MCM-41 and its application in Knoevenagel condensation reaction. Amine modified MCM-41 was prepared by co-condensation and post-synthesis methods. The samples were characterized by X-ray powder diffraction, Fourier-transfer infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron micrograph (SEM), 29Si magic-angle spinning (MAS), nuclear magnetic resonance (NMR), diffuse reflectance spectra (DRS), nitrogen adsorption–desorption and CHN analysis. X-ray diffraction patterns indicate that the modified materials retain the standard MCM-41 structure. SEM study exhibits that the arrangement of particles for 12.8% amine modified MCM-41 is well ordered and spherical in nature. CHN analysis supports that complete hydrolysis of ethoxy groups take place in 12.8% amine modified sample. From the NMR study it is confirmed that the surface coverage is 40% in 12.8% amine modified sample. The base catalytic activity of hybrid MCM-41 materials such as amine (post-synthesis and co-condensation methods) and surfactant functionalized materials for condensation reaction between benzaldehyde and diethyl malonate in solvent free, room temperature synthesis of cinnamic acid was evaluated and correlated with the surface and textural properties. Sample containing 12.8 wt% amine loaded by co-condensation method showed highest malonic ester conversion (92%) and selectivity (98%) for cinnamic acid.

The mesoporous molecular sieve MCM-41 was synthesized by sol–gel method using tetraethyl orthosilicate (TEOS), cetyl trimethyl ammonium bromide (CTAB), aqueous NH3 and water. A series of sulfate modified MCM-41 was prepared by incipient wetness impregnation method using H2SO4 as sulfatising agent. The samples were characterized by BET surface area, X-ray diffraction, FT-IR and TG–DTA. The catalytic activity of the samples was evaluated for nitration of phenol with nitric acid in dichloro ethane (DCE) medium, at room temperature. The effect of reaction parameters, i.e. time, concentration of nitric acid and phenol/nitric acid ratio were also investigated. Modification with sulfate opened new opportunities to generate active Bronsted and Lewis acid sites in the stabilized nanostructure MCM-41. Among the catalysts screened, 4 wt.% sulfated MCM-41 showed maximum activity (93%), with 90% selectivity towards ortho-nitrophenol.