Abstract: MCM-41 mesoporous molecular sieves impregnated with MgO, MoO3, and Mo2C were synthesized using a wet impregnation method. The compounds developed herein, were characterized by means of XRD, SEM-EDS and FT-IR techniques. The production capacity of acetaldehyde from ethanol was analyzed by catalytic processes employing as-synthesized MCM-41. The obtained results show that the changes in crystallinity of MCM-41 were generated by the impregnation of oxides, which generate damage to the structure of MCM-41. Nevertheless, the characteristics of the compounds show a favorable reactivity behavior, allowing them to be used as heterogeneous catalyst material due to the similarity of the characteristics between MCM-41 with and without Mg and Mo oxides. The catalytic tests show the influence between the type of catalyst used and the temperature applied to the selective process of acetaldehyde from ethanol, obtaining the best results in the samples impregnated with Mo2C at 250 °C, with a production percentage of acetaldehyde of 80.7% and 77.9% for the catalysts impregnated with 0.5% and 2.0% Mg and 3.0% Mo carbide, respectively.

AbstractAl-MCM-41, 16%Ba/Al-MCM-41 and 1.4%Cr-16%Ba/Al-MCM-41 were used as catalysts in the vapor-phase catalytic conversion of ethanol. Physical-chemical properties of the catalysts and the effect of barium and chromium on the Al-MCM-41 activity and 1,3-butadiene yield were studied. The catalysts were characterized by X-ray diffraction (XRD), N2 physisorption (BET method), CO2chemisorption and Fourier transform infrared spectroscopy (FT-IR). When ethanol was completely converted on Al-MCM-41 and 16%Ba/Al-MCM-41, the reaction products showed a high selectivity for ethylene (90-98%). However, on the 1.4%Cr-16%Ba/Al-MCM-41 catalyst, a greater number of reaction products were obtained such as ethylene, acetaldehyde, diethyl ether and 1,3-butadiene. The maximum 1,3-butadiene yield obtained from ethanol reaction was 25% at 723 K and W/FEtOH = 15 g h mol-1. The latter result was obtained in a single step and without addition of reaction promoters (e.g., acetaldehyde, crotonaldehyde, hydrogen) in the feed stream to the reactor.