The hydrogenolysis of tetrahydrofurfural alcohol to 1,5-pentanediol was studied over a series of carbon-supported metal/metal-oxide pairs. In agreement with previous reports, specific pairs, especially Pt and Ir paired with WOx, MoOx and ReOx, exhibited high activity and selectivity, even though the individual components were not active or selective. Only reducible oxides produced selective catalysts. A more comprehensive study of the Pt-WOx system indicated that the active form of the catalyst exists as a thin, submonolayer film of the oxide on the Pt surface. This film could be formed by atomic layer deposition (ALD) of W(CO)(6) onto the Pt nanocrystals and STEM-EDS mapping demonstrated that ALD deposition occurred selectively on the Pt. When the catalyst was formed by impregnation of Pt and W salts, the WOx was mobile and able to move onto the Pt. The implications of these result for preparing selective catalysts are discussed. [GRAPHICS] .