Getting insights into bohemite structure using thermal analysis

High purity aluminas (HPA) are used extensively in a variety of applications, ranging from microelectronics to catalysis. Aluminum hydroxides are among the primary raw materials for the production of aluminas, with microstructure (e.g. porosity), chemical makeup of the latter being to a significant extent inherited from the precursor. Present research demonstrates a novel use of the run-of-the-mill thermal analysis (TGA) data. We used kinetic mathematical modeling, as a tool to get insights into the structure of a series of high-purity bohemites (produced via alkoxide method) and pseudo-bohemites (nitrate-ammonia deposition). This approach, made it possible to obtain both quantitative (apparent dehydration kinetics, activation energy) and qualitative (porosity, preferential crystallites orientation) information on these samples. These characteristics serve as predictors of the future performance of the formed HPA catalytic carrier. We believe, that given the ubiquitous nature of TGA, this methodology can be of use for a wide range of readership working with bohemite and pseudo-bohemite type hydrated aluminas.