The dehydroxylation of SiO2 and adsorption and thermal decomposition of CH3OH on dehydroxylated SiO2 prepared at extreme temperatures up to 1475 K has been studied using transmission infrared spectroscopy. Formation of Si-O-Si linkages (as evidenced by 888 and 908 cm(-1) bands) is directly related to the loss of the isolated SiO-H band at 3748 cm(-1) during SiO2 dehydroxylation to produce H2O. High-resolution (0.75 cm(-1)) studies of the isolated SiO-H band show sharpening and a slight 4 cm(-1) shift to higher frequency with decreasing -OH coverage and may be explained by site inhomogeneity effects. Adsorption of CH3OH on dehydroxylated SiO2 occurs first by reaction with SiOSi sites, followed by exchange with SiOH groups at elevated temperatures leading to SiOCH3 surfaces species. (CH3OH)-O-18 adsorption studies demonstrated that adsorption on SiOSi sites occurs by cleavage of the methanol O-H bond forming SiOH and (SiOCH3)-O-18. Thermal decomposition of SiOCH3 groups creates SiHx(x = 1,2) species and prevents formation of the SiOSi sites indicative of the production of free radical sites at the surface. At temperatures above 1300 K, SiHx decomposition leads to SiOSi site formation.