Layered double hydroxides (LDHs) with a cation composition of LiAl2 have a wide range of potential applications as catalysts, catalyst supports, and precursors for refractory oxide materials, including several industrially important lithium aluminate phases. The understanding of the calcination behavior of this group of LDH phases is essential to advancing these applications, and the research described here focuses on the thermal decomposition and structural evolution of LiAl2(OH)(6)Cl . nH(2)O in the temperature range of 20-1100 degreesC. Al-27, Cl-35, and Li-6,Li-7 magic angle spinning nuclear magnetic resonance spectroscopy, powder X-ray diffraction, thermal analysis (including thermogravimetric and differential scanning calorimetry), and compositional analysis provide a highly consistent picture of the thermally induced phase formation and transformations of this LDH. The loss of the surface and interlayer water can begin as low as room temperature, depending on the relative humidity. Beginning at about 300 degreesC, the simultaneous volatilization of H2O and HCl and the exsolution of crystalline LiCl result in the formation of amorphous Li-Al-O-OH. By at least 500 degreesC, volumes with the structures of alpha -LiAlO2 and LiAl5O8 appear, and these phases become progressively more ordered with increasing temperature, LiCl begins to volatilize by 850 degreesC and is present only in trace amounts above ca. 1000 degreesC. alpha -LiAlO2 converts to gamma -LiAlO2 between 970 and 1100 degreesC. Because of the delithiation due to LiCl volatilization, the final products are dominated by LiAl5O8, in contrast to the calcination products of previously studied LiAl2 LDHs which are dominated by LiAlO2.