The adsorption and thermal stability of vinyltriethoxysilane (VTES) was studied on a gamma-Al2O3 surface. Adsorption occurs near room temperature with the production of ethanol from the reaction with isolated surface Al-OH groups, producing the surface species Al-O-Si(OC2H5)(2)CH=CH2. As the surface is heated, decomposition of Al-O-Si(OC2H5)(2)CH=CH2 occurs first via loss of the OC2H5 groups (starting at similar to 520 K) and then with loss of the CH=CH2 groups (starting at similar to 820 K). Below 375 K, ethanol is the sole gas phase product produced, and near 520 K, both ethanol gas and ethylene gas are produced. At higher temperatures, ethanol decomposes on the surface and ethylene is the only gas phase species present. The thermal stability of ethoxy groups on the VTES-treated Al2O3 surface decreases considerably under strong hydrolysis conditions in water vapor. There is also a decrease in the stability of the vinyl groups under strong hydrolysis conditions. Above similar to 525 K, Si-OH infrared bands are observed to develop as Al-OH groups disappear. Above similar to 1100 K, organic ligands are no longer detected on the surface by FTIR spectroscopy and the surface remains covered with a silicate overlayer.