Surface chemical properties of active carbons and their effects on NO reduction over the carbon-supported copper oxide catalysts

摘要

Active carbons are an important adsorbent and a catalyst support. It is naturally composed of crystallites in nearly amorphous state. Hence a wide-spread peak appears at a much lower diffraction angle in XRD diffraction patterns It is generally thought that the amount of oxygen contained in active carbons is an important factor affecting the chemical properties of an active carbon itself. And the amount and the distribution of oxygen-containing groups on active carbons were found to be related with activation procedures. However, it is impossible so far to control them by the activation procedures. Thus, little information is known on the roles of surface oxygen-containing groups in catalyst preparation and reaction process. In this work, four kindsof active carbons, namely CSAC, HNAC, MPNAC, and CAC, made of coconut shell, hawthorn nut, mountain peach nut and coal respectively were used. It was found that the oxygen-containing groups were reactive centers of NO reduction when active carbons werenot impregnated with eupric ions In addition, the oxygen-containing groups were also nucfeation centers of impregnated eupric ions. Thus, the distribution of the oxygen-containing groups indeed governed the dispersion of metallic ions.