The catalytic activity of a highly reactive and attrition resistant regenerable CuO/gamma-Al2O3 desulfurization sorbent for NOx reduction was determined in a fluidized-bed reactor. The NO conversion over the sulfated catalyst was found to be higher than that obtained over the fresh/oxidized catalyst, with the optimum temperatures for the maximum NO removal at 350 degrees C for both catalysts. The decrease in NO conversion above the optimum temperature is attributed to the increase in the rate of the parallel NH3 oxidation reaction. High levels of ammonia oxidation (i.e., >96%) was observed in absence of oxygen and NO with oxidized sorbent/catalyst, indicating the participation of the lattice oxygen ions in the CuO/gamma-Al2O3 particles in the NH3 oxidation reaction. The presence of steam enhances the catalytic activity of the catalysts providing a wider optimum temperature window, thus resulting in a more flexible operation for simultaneous SOx/NOx removal from flue gas. (C) 2012 Elsevier B.V. All rights reserved.