The adsorption and subsequent reaction of phosphorus trifluoride (PF3) on a gamma-alumina (gamma-Al2O3) surface was studied using high vacuum techniques and transmission infrared spectroscopy (FT-IR) over a temperature range of 150-800 K. Phosphorus trifluoride molecules adsorb on the alumina surface between 150 and 230 K, via an interaction with surface isolated hydroxyl groups, to form OH-FPF2 and/or (OH)-PF3 intermediate species. The O-H bond of the proposed intermediate is thermally activated, and at sample temperatures >230 K, the phosphorus center inserts into the O-H bond of the hydroxyl group, generating surface hypophosphoryl fluoride species of the form FHPO. Reaction of PF3 molecules with associated hydroxyl species occurs from extended thermal treatment at 310 K to yield additional hypophosphoryl fluoride species of the form FHPO2. Infrared band assignments are presented. The new species are stable on the aluminum oxide surface to a thermal treatment temperature of 800 K under evacuation. The hypophosphoryl fluoride species resist extensive oxidation when heated in O-2 gas at 700 K.