Synthesis, characterization and catalytic activity of copper incorporated and immobilized mesoporous MCM-41 in the single step amination of benzene

Abstract

The paper reports the synthesis, surface and textural characterization of copper and amine modified MCM-41 and its application for the single step animation of benzene to aniline at 70 degrees 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), (29)Si magic-angle spinning (MAS) and (13)C 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. (C) 2009 Elsevier B.V. All rights reserved.