Nitrogen oxides (NO_x) emissions from stationary electricity generation sources have been implicated as contributors to environmental problems such as acid rain, photochemical smog, and ozone layer depletion. The selective catalytic reduction of NO_x by carbon monoxide is one technology being considered to meet increasingly stringent regulations on NO_xemissions, as this method may avoid the need for reducants such as urea or ammonia. In this work CuO catalysts were prepared on three different mesoporous supports (SBA-15, MCM-41 and MCM-48). We investigated the influence of catalyst support properties, CuO loading, and ceria as a catalytic and structural promoter, on the reduction of NO_x by CO in a differential reactor. The catalysts were characterised by N2 adsorption, XRD and TPD. The best NO_xconversion was achieved with the SBA-15 supported catalyst containing 10 % CuO, with a conversion of 50 % at 500 ºC. Ceria was not found to have a beneficial effect on NO_xconversion. These results suggest that the conversion of NO_x by catalytic reduction in CO is still too low for practical applications, and further improvements in catalyst and process conditions are required.