We have studied the activity and selectivity of Pd/gamma-Al2O3, VOx/gamma-Al2O3 and Pd-VOx/gamma-Al2O3 catalysts for the decomposition of NO and the reduction of NO with CO. Pd-VOx/gamma-Al2O3 catalysts were prepared by anchoring Pd(AcAc)(2) on VOx/gamma-Al2O3. Characterization of the binary samples by hydrogen chemisorption and TPR measurements indicated that the reduction of VOx is enhanced by a close contact with palladium and that partially reduced vanadia decorate noble metal particles. This palladium-vanadium interaction alters the catalytic properties of palladium: the activity for NO decomposition is higher for the binary sample and, for the NO-CO reaction, both the activity and the selectivity to N-2 increase when vanadium is in contact with palladium. (C)2000 Elsevier Science B.V. All rights reserved.