Structural and surface properties of highly ordered mesoporous magnesium-aluminium composite oxides derived from facile synthesis.

Highly ordered mesoporous magnesium-aluminium composite oxides (denoted as OMMA-x) with a variety of n Al / n Mg ratios have been successfully synthesized via a facile strategy, and a salt effect was proposed to explain the formation mechanism. The incorporation of Mg can significantly improve the structural and surface properties of ordered mesoporous alumina (OMA) material. The resultant OMMA-x exhibited a much more ordered 2-D hexagonal mesostructure, a narrower pore size distribution, a higher specific surface area and pore volume, and a stronger basicity than those of OMA. More importantly, the highly homogeneous incorporation of Mg at the atomic level and the formation of framework Mg O Al bonds could effectively suppress the formation of crystalline alumina during the calcination process. As a result, OMMA-x demonstrated a superior thermal stability. For example, the ordered mesostructure of OMMA-8 could be well maintained with a high surface area of 182 m 2 /g even after thermal treatment at 1000 °C. [ABSTRACT FROM AUTHOR]