Integrated study of the calcination cycle from gibbsite to corundum

A comprehensive picture of the gibbsite (Al(OH)(3)) to corundum (alpha-Al2O3) calcination process has been developed by multi-technique characterization of an integrated sample set. In 100 degrees C calcination stages, Al-27 nuclear magnetic resonance (NMR), differential thermal analysis (DTA), X-ray diffraction (XRD), and nitrogen sorption surface area measurements were employed to elucidate the structure and chemistry of these calcinates. In addition, positron annihilation lifetime spectroscopy (PALS) has been used to study the defective nature of these aluminas. By exploiting the complementarity of PALS, Al-27 NMR, and N-2 sorption, new links were established between particle morphology, local atomic coordination, and surface defect chemistry.