Influence of Ce addition on the catalytic behavior of alumina-supported Cu–Co catalysts in NO reduction with CO

The effect of Ce addition to alumina-supported copper, cobalt, and copper–cobalt oxides with low loadings on the catalysts efficiency in NO reduction with CO was studied. The attention was focused on varying the impregnation procedure in the ternary-supported catalysts in order to determine the best catalyst as well as the reasons for the enhanced catalytic activity. Ternary Co–Cu–Ce and binary Co–Ce, Cu–Ce, and Cu–Co-supported alumina were prepared and characterized by ICP, XRD, TEM, adsorption studies, XPS, H2-TPR, and catalytic investigations. The high activity of the ternary and the binary catalysts was determined by the favorable influence of the added cerium on the dispersion of the copper and cobalt active phases. The presence of ceria contributes to the formation of appropriate active phases, resulting in catalytic sites on the surface of the samples that promote the reduction of NO with CO.

Graphical abstractThe ceria-promoted alumina-supported copper and cobalt catalysts with metal loadings up to 4% total metal are effective in the reduction of NO with CO. The addition of cerium in the binary systems affects the activity at temperatures over 130 °C, whereas the activity of the ternary-supported catalysts is enhanced even at room temperature.Figure optionsDownload full-size imageDownload high-quality image (123 K)Download as PowerPoint slideResearch highlights► Ce-promoted Cu and Co catalysts are active in NO reduction with CO up to 300 °C. ► Ce affects on binary catalysts activity over 130 °C. ► Ce affects on ternary catalysts activity at room temperature. ► Ce influences on the dispersion of the copper and cobalt active phases. ► Ce promotes the formation of catalytic active sites for NO reduction with CO.