Synthesis and Characterization of Homogeneously Mesoporous Magnesium Silicates with Prospects of Application in Catalysis and Adsorption

摘要

Isotherms of low-temperature nitrogen adsorption-desorption by a mesostructured magnesium silicate material produced using a supramolecular cetylpyridinium template, liquid glass, and solutions of magnesium salts with different Mg/Si ratios have been measured. Homogeneously mesoporous adsorbents with a developed specific surface area (1045-1195 m(2)/g, from BET data) and high cumulative mesopore volume (1.210-1.646 cm(3)/g) have been synthesized. The samples' most specific characteristic features include a narrow mesopore size distribution with predominant sizes in the range approximate to 3.1-3.6 and a hysteresis of a hybrid shape indicating to the presence of a combination of tubular and slitlike mesopores in the form of TWT-structures. "Mesoporous molecular sieves" of the MCM-41 type and, alternatively, with the increase of the Mg/Si ratio, of the MCM-48 type with hexagonal and cubic pore structures, respectively, have been identified in the samples.