High temperature reactions in industry require catalysts with high stability. Basic metal oxides, K2O and La2O3, were added to gamma-Al2O3 in order to obtain supports with low acidity and high surface areas at high temperatures. Microcalorimetry and FT-IR were employed to determine the surface acidity and basicity using ammonia and carbon dioxide as the probe molecules. It was found that the addition of basic metal oxides inhibited the transformation of gamma-Al2O3 to the forms such as theta-Al2O3 and alpha-Al2O3 when calcined at 1000degreesC. Instead, X-ray diffraction (XRD) results indicated the formation of aluminates for the supported samples. The 6% K2O/gamma-Al2O3 sample retained high surface area of 188 m(2) g(-1) and strong basicity (170 kJ mol(-1) for CO2 adsorption) when calcined at 600 degreesC. The sample retained the surface area of about 100 m(2) g(-1) when calcined at 1000 degreesC. In this case, the sample possessed low acidity and basicity and may be used as a neutral support with high thermal stability. The addition of La2O3 onto gamma-Al2O3 might cause even more loss of surface area when calcined at high temperatures. The formation of a perovskite phase LaAlO3 on the surface of the La2O3/gamma-Al2O3 samples calcined at 1000 C led to the low acidity and basicity.