Physical Adsorption on Chemisorbed Films

Improving textural properties of γ-alumina by using second generation biomass in conventional hydrothermal method

“…g-Alumina prepared by conventional hydrothermal method using highly crystalline boehmite or bayerite usually exhibits SSA in the range of 40e120 m 2 /g and pore volume of approximately 0.3 cm 3 /g [13], or SSA up to 200 m 2 /g with pore diameter lower than 3 nm [4]. In contrast, sophisticated methods usually yield alumina with improved or tailored textural properties (Table 1).…”

“…4. Eta and gamma alumina were obtained by thermal treatment of bayerite and boehmite, respectively [4]. It is noteworthy that bayerite was converted into boehmite upon dehydration.…”

“…Alumina precursors as boehmite and bayerite are prepared by the conventional hydrothermal routes [3], yielding after a thermal treatment in the range of 500e700 C, g-alumina which exhibits specific surface areas (BET) up to 200 m 2 /g [4]. However, this simple and cheap method does not lead to large pore sizes and volumes [2].…”

Modificación superficial mediante la adición de ácido cítrico en catalizadores NiWS soportados en alúmina-titania (AT₂) para la hidrodesulfuración de 4,6-dimetil dibenzotiofeno

“…El amoníaco es una molécula básica que puede interaccionar fuertemente con los grupos O-H superficiales que están vinculados directamente con la acidez de los materiales. Tres clases de fuerza de sitios ácidos se han reportado: débiles (25-200°C), intermedios(200-400°C) y fuertes (>400°C) [90,91]. En el sistema Al 2 O 3 se pudo apreciar un mayor contenido de sitios ácidos débiles con respecto a todos los materiales con su máximo a 160 °C.…”