Effects of the ratio of Cu/Co and metal precursors on the catalytic activity over Cu-Co/Al2O3 prepared using the polyol process

Cu-Co bimetallic catalysts were prepared using a simple polyol process. The effects of various metal precursors (nitrate, acetate, and chloride) and Cu/Co ratios on the activities of the catalysts were evaluated for toluene oxidation and NO reduction. The results indicated that the use of the metal precursor Cu-Co acetate in preparing the bimetallic catalysts resulted in good metal dispersion and high catalytic activity. When the atomic Cu/Co ratio was 0.21 in the Al2O3-supported catalyst, the dispersion of active sites was promoted by the Cu, and the catalytic activity was stable over the reaction time. CuO and Cu0 species and large particle sizes (20 nm) formed when the Co loading weight in the catalyst increased, and conversion decreased. When the reaction temperature was 300 °C, NO and toluene were able to be simultaneously removed with high conversion rates (83% and 98%).