The adsorption of molybdenum hexacarbonyl is studied on thin hydroxylated and partially hydroxylated alumina films using reflection-absorption infrared, X-ray photoelectron, and temperature-programmed desorption spectroscopies. The majority of the Mo(CO)(6) adsorbed on hydroxylated alumina at 80 K desorbs at similar to 200 K; the remainder decarbonylates leading to a molybdenum coverage of similar to 2% of a monolayer. Subcarbonyl species are detected as the sample is heated to similar to 200 K and, at higher temperatures, the molybdenum is oxidized to an similar to+4 oxidation state and deposits primarily oxalate species on the surface. The adsorbed oxalates thermally decompose at similar to 300 K to evolve CO to form adsorbed bidentate carbonate species. These are stable to similar to 560 K and react to evolve CO at this temperature. The amount of molybdenum absorbed onto the surface can be increased by repeatedly dosing Mo(CO)(6) at 80 K and annealing to similar to 200 K to desorb molecular molybdenum hexacarbonyl where the molybdenum coverage increases by similar to 2% of a monolayer for each cycle. It is also found that the extent of decarbonylation depends on the degree of alumina hydroxylation so that heating hydroxylated alumina to 900 K, which removes similar to 50% of the surface hydroxyls, decreases both the CO desorption yield and the oxalate coverage by 50%.