We present results which demonstrate that a 1% Pt/alumina catalyst prepared by a sol-gel technique is superior in its Nz selectivity in the catalytic reduction of NO, by propene to similarly loaded Pt/alumina catalysts prepared by the more commonly used impregnation technique. The selectivity of the sol-gel catalyst to Nz at maximum conversion is 83% as compared to 43% and 60% selectivity observed with Pt catalysts prepared using the impregnation technique. The sol-gel made catalyst does not change its activity and selectivity even in the presence of 2.5% water.