Synthesis and Characterization of Robust γ-Alumina Monolith with Hierarchical Pore Structure, High Specific Surface Area and Novel Macropore Morphology

A three-dimensional interconnected macroporous alumina monolith was successfully prepared by phase separation combined with microwave-hydrothermal process in ammonia solution. The material calcined at 500 °C could be converted into highly-crystalline γ-alumina with a high surface area of 321 m2/g and narrow bimodal pore size distributions, centered around 12 nm and 240 nm, respectively. The monolith possesses hierarchical meso-macro structure, which is essential for the enhanced accessibility of the active sites by large reactant molecules.