화학공학소재연구정보센터
Chemical Engineering Journal, Vol.172, No.2-3, 1054-1065, 2011
Catalytic activity of nitrogen-containing molecular sieves and nitrogen-containing carbon for alpha,beta-unsaturated esters production
Nitrogen-containing molecular sieves and nitrogen-containing carbon were prepared and characterized by various spectroscopic tools such as powder X-ray diffraction (XRD), N-2 adsorption-desorption isotherms, Fourier transformed infra-red (FTIR) and Raman spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The catalytic properties of the solids exhibited different yields of ethyl 2-cyano-3-propylacrylate (ECPA) via Knoevenaguel reaction, according to their amount of nitrogen incorporated to the solids. The influence of reaction parameters such as the feed composition, temperature, type of solvent and catalyst loading was also evaluated. It was shown that in addition to the amount of nitrogen, the accessibility of the sites to the reactants is a key factor for high catalytic activity. The best conditions investigated for the production of ECPA were a BUT/ECA molar ratio of 1 and a reaction time of 1 h at 30 degrees C. 50 mg of catalyst is optimal for the reaction, but in general, the mass depends on other parameters such as the amount of reactant. Characterisation of the spent NC catalyst through BET surface area, GC-MS, SEM, Raman and infrared spectroscopy indicated that the loss of nitrogen basic sites is the main pathway for deactivation of the catalysts. (C) 2011 Elsevier B.V. All rights reserved.