ONE-STEP PREPARATION OF POLYMER-SUPPORTED COLLOIDAL PALLADIUM CATALYSTS AND THEIR CATALYTIC PROPERTIES .2. STABILITY AND CATALYTIC PROPERTIES IN OLEFIN HYDROGENATION

The catalytic properties in the hydrogenation of olefins and the stabi lity of polymer-supported colloidal palladium catalysts prepared by a one-step preparation method (OSPM) have been investigated. The influen ce of the structure of the catalyst and solvents on the catalytic prop erties and stability were studied. A comparison of catalytic propertie s and stability between polymer-supported colloidal Pd catalysts prepa red by different methods and also between polymer-supported and SiO2-s upported Pd catalysts has been made. Experimental results show that th e catalysts prepared by OSPM possess high catalytic activity for hydro genation of olefins with low metal loss and good stability. Their exce llent catalytic properties seem to arise from the highly dispersed and uniform dispersion of active metal, and also from the effective prote ction of the active metal by polymer. Proposals for the reducing loss of metal catalysts from supports are made.