A NEW APPROACH TO THE PRETREATMENT OF ELECTROLESS-PLATED CU AL2O3 CATALYSTS/

This study employed incipient wetness impregnation to deposit palladiu m instead of the conventional pretreatment process to prepare the elec troless plated copper catalysts of different palladium and copper load ings. The copper surface area and the copper dispersion were determine d by the decomposition of nitrous oxide. Temperature-programmed reduct ion (TPR) was used to analyze the reducibility of oxide copper and its interaction with palladium. Different temperatures of calcination wer e tried in order to understand the redispersion of copper crystallites . The experimental results showed that the copper loading attained a m aximum when palladium loading was 0.67 wt%. The copper surface area an d the dispersion decreased with increasing calcination temperatures. A t high copper loading, the redispersion of copper crystallites started at 600 degrees C, which induced the increase of the copper surface ar ea and the dispersion. The reduction temperature of CuO decreased with the increase of palladium loading, indicating an interaction between palladium and copper. (C) 1997 Elsevier Science B.V.