Abstract
New zirconium-porous clay heterostructures (PCHs) were prepared using zirconium-tetramer-intercalated clay mineral as precursors and a subsequent reaction with alkylamine molecules and a silica source, such as tetraethyl orthosilicate. The organic molecules were removed by calcinations at temperatures above 550 degrees C. The precursors and resulting materials were systematically characterized using different techniques: XRD, XRF, Si-29 MAS NMR, N2 adsorption, and TG-DTG. The thermal stability of the zirconium precursor and porous clay heterostructure was reported for the first time using in situ XRD high temperature. The zirconium content in the PCHs was tuned using the starting precursors with different zirconia percentages, and its presence improved the thermal stability, microtextural properties, and acidity of the PCH materials compared to the conventional PCH materials. The length of the alkyl amine chains used also affected the previously mentioned properties. A higher surface area of 950 m(2) g(-1) and pore volume of 0.801 cc g(-1) were obtained using dodecylamine molecules and Zr-intercalated clay with a starting ratio of Zr (mole) to grams of clay of 6. The zirconium-porous clay heterostructures were stable up to 650 degrees C, with a total acidity concentration of 0.993 mol g(-1) of PCH, in addition to strong Bronsted and Lewis acid sites, which were detected at 500 degrees C in vacuum.