STUDY OF RHCO BIMETAL CATALYST .2. DYNAMI C BEHAVIOR OF THE CHEMISORBED CO AND CO DISPROPORTIONATION ON RH+CO AL2O3/

The forms of adsorption sites, dynamic behavior of chemisorbed CO and CO disproportionation have been investigated by using CO and NO as dou ble probes and TP - IR dynamic method. The results indicate that there are a large amount of adsorption sites for gem dicarbonyl CO and a ve ry small amount of adsorption sites for linear CO on Rh, and Co sites for adsorbed NO over Rh + Co/Al2O3. The bands of gem - dicarbonyl CO g radually decreased in intensity and fully desorbed at 300 degrees C du ring TPD(in vacuum) dynamic process. The temperature fully desorbed fo r gem - dicarbonyl CO on Rh + Co/Al2O3 is lower than that for gem - di carbonyl CO on Rh-4/Al2O3 indicating that addition of Co weaken CO ads orption strength on Rh-I sites over Rh + Co/Al2O3. The results obtaine d from TP (in CO) dynamic process indicate that CO disproportionation take place above 250 degrees C and the rate of CO disproportionation o n Rh-I sites is higher than that on linear sites CO over Rh + Co/Al2O3 .