Abstract Mesoporous silicate were synthesized by a not hydrothermal method and the acid sites were promote by adding zirconium and sulfate ions. The maximum acid strength of the mesoporous silicate was promoted by addition of zirconium during the synthesis process and sulfate ions was add by insipient impregnation, after the mesoporous silicate synthesis. The materials were characterized by TGA, XRD, FT-IR, BET, potentiometric titration with n-butylamine, SEM and TEM techniques. The catalytic activity of the materials was evaluated for the ethanol dehydratation. The zirconium atoms and sulfate ions incorporation had a favorable impact on the acid strength of sites going from -42 to 143 mV. The hexagonal arrangement mesoporous material is slightly affected, indicating that ZrO2 nano crystals are within the silicate matrix. At the same way affected the sulfate ions presence.

Resumen Los silicatos mesoporoso fueron sintetizados por un método no hidrotérmico y los sitios ácidos fueron promovidos por la adición de circonio e iones sulfato. La máxima fuerza ácida del silicato mesoporoso fue promovida por adición de circonio durante el proceso de síntesis del silicato y luego por impregnación insipiente con iones sulfatos, después de la obtención del silicato mesoporoso. Los materiales se caracterizaron por las técnicas TGA, DRX, FT-IR, BET, titulación potenciométrica con n-butilamina, SEM y TEM. La actividad catalítica se evaluó en la deshidratación de etanol. La presencia del óxido de circonio y iones sulfato tuvo un impacto favorablemente en la generación de la fuerza ácida de los sitios, pasando de -42 a 143 mV. El arreglo hexagonal del material mesoporoso es ligeramente afectado, indicando que cristales de ZrO2 están dentro de la matriz del silicato. También de la misma manera afectan la presencia de los iones sulfatos.

This work reports the synthesis of titanium oxide (TiO2) and sulfated titanium oxide (TiO2-SO4(2-)) obtained by thermal hydrolysis of titanium tetrachloride. Titanium hydroxide synthesized by this method was impregnated with a 1 N H2SO4 solution, to give amounts of sulfate ions (SO4(2-)) of 3 and 7 wt%. The synthesized samples were dried at 120 °C during 24 h and then calcined for 3 h at 400 °C. Thermal analyses, X-ray diffraction, nitrogen physisorption, infrared spectroscopy, potentiometric titration with n-butylamine, U.V.-visible diffuse reflectance spectroscopy and scanning electron microscopy were used to characterize the materials. The results of physicochemical characterization revealed that a mixture of crystalline structures, anatase, brookite and rutile developed in the titanium oxide, stabilizing the anatase structure in the sulfated titanium oxides, and coexisting with a small amount of brookite structure. The synthesized mesoporous materials developed specific surface areas between 62 and 70 m² g-1, without detecting an important influence of sulfation on this parameter. The presence of sulfate ions improved the acidity of titanium oxide and modified the characteristics of light absorption in the 425-600 nm region, which suggests the possibility of using these materials in reactions assisted by visible light.

The use of Al2O3TiO2 mixed oxides are proposed as catalytic supports for hydrotreating processes to remove sulfur and nitrogen heteroatoms from petroleum heavy cuts. Pure Al2O3 and TiO2 oxides as well as their mixtures containing 20, 35, 50, 65 and 80 mol percent on TiO2 were prepared by the solgel method. They were calcined at 500, 550 and 600ºC under an air flow of 1.2 L/h. The supports were characterized by Xray diffraction, physical adsorption of nitrogen, and nbutylamine potentiometric titration.They were then impregnated with a solution of cobalt nitrate and ammonium heptamolybdate, to obtain a concentration of 2.8 Mo atom/nm². The catalytic activity of the solids was measured for the vacuum heavy gasoil HDS at 350 ºC and 80 kg/cm². The sulfur removal obtained with this catalyst was higher than that of a reference industrial catalyst

Se propone la utilización de óxidos mixtos de alúmina y titania como soportes catalíticos en procesos de hidrotratamiento, para remover los heteroátomos de nitrógeno y azufre de cortes pesados de petróleo. Mediante el método solgel, se prepararon óxidos puros de Al2O3 y de TiO2 así como sus mezclas con 20, 35, 50, 65 y 80% en mol de TiO2. Estos fueron calcinados a 500, 550 y 600ºC, bajo corriente de aire de 1.2 L/h. Las muestras de sólidos fueron caracterizadas por medio de difracción de rayosX, adsorción física de nitrógeno y titulación potenciométrica de nbutilamina. Los soportes se impregnaron con una solución de nitrato de cobalto y heptamolibdato de amonio, para obtener una concentración de 2.8 átomos de Mo/nm². Estos catalizadores se sometieron a reacción de HDS de un gasóleo pesado de vacío a 350ºC y 80 kg/cm². Se concluye que con la metodología propuesta, se obtiene un porcentaje de eliminación de azufre mayor que con un catalizador industrial de referencia