Oxidacion y dhidrogenacion de etanol catalisis

OXIDATIVE DEHYDROGENATION OF ETHANOL OVER MgCrO CATALYSTS
Pedro F. Castro1, María del Carmen Viola1, José C. Pedregosa1*, Manuel F. Gomez2,
and María C. Abello2§
1Area de Química General eInorgánica, "Dr. Gabino F. Puelles", Facultad de Química, Bioquímica y Farmacia, UNSL, Chacabuco y Pedernera, 5700-San Luis, Argentina.
2INTEQUI, Instituto de Investigaciones en Tecnología Química(UNSL-CONICET), Chacabuco y Pedernera, 5700-San Luis, Argentina. Tel./fax: 54-2652-426711.
E-mail: *jpedreg@unsl.edu.ar § cabello@unsl.edu.ar
Received October 2, 2008. In final form February 2, 2009.ABSTRACT
MgCrO catalysts have been prepared from the corresponding acetates following three different procedures and they were characterized by X-ray diffraction, BET specific surface area, FTIR andEPR. The characterization results revealed that a spinel highly organized with an excess of oxygen at the surface was obtained irrespective of preparation method. The initial crystallization temperaturewas around 450°C, lower than that required if the preparation was from oxides. The samples calcined at 500°C were tested in oxidative dehydrogenation of ethanol. They were active at 260ºC withselectivity to acetaldehyde higher than 75%. The sample obtained by using citric acid led to a relatively lower COX formation due likely to a lower oxygen excess at the surface.
Keywords: catalysts,characterization methods, chemical synthesis, MgCr2O4, MgCrO catalysts, oxidative dehydrogenation of ethanol.
243 P. F. Castro et al.
RESUMEN
Se prepararon catalizadores MgCrO a partir de loscorrespondientes acetatos por tres procesos diferentes y se caracterizaron por sus diagramas de polvo de difracción de RX, área superficial específica (BET), espectros infrarrojos y Resonancia ParamagnéticaElectrónica. Los resultados de la caracterización indican que una fase espinela altamente organizada, con un exceso de oxígeno sobre la superficie, es siempre obtenida. La temperatura inicial de...