In the H-2/O-2 reaction, the desorption of OH from a polycrystalline palladium foil has been studied with Laser-Induced Fluorescence (LIF) as a function of the hydrogen mixing ratio, alpha(H2), and the temperature. The water production as a function of alpha(H2) was also monitored with microcalorimetry. The apparent desorption energy, E-OH(a), for OH has been measured from alpha(H2) = 0% to alpha(H2) = 74%. At alpha(H2) = 0%, E-OH(a) was measured to be 143 +/- 7 kJ/mol; the apparent desorption energy then increases linearly with alpha(H2) to a maximum value of 223 +/- 6 kJ/mol at alpha(H2) = 40%. At higher alpha(H2), the apparent desorption energy was measured to be constant at about 200 kJ/mol. The maximum in apparent desorption energy at alpha(H2) = 40% occurs at the same alpha(H2) as the maximum in water production. This phenomenon has also been reported for the platinum metal, although at an alpha(H2) value of 20%. The relative coverage of intermediates and products on the palladium catalysts was obtained using Chemkin.