Abstract
Temperature programed decomposition of Mo (CO)6 adsorbed on Bi2O3-Al2O3 was studied and metathesis reaction of olefin was performed on it. Decarbonylation of Mo (CO)6 on Bi2O3-Al2O3consists of two peaks having maxima at around 150 and 320°C. The characteristics of these two decarbonylation processes are quite similar to those on Al2O3 except the appearance of a shoulder on the high temperature peak. The low temperature peak is considered to correspond, to a reversible formation of Mo(CO)3 but the high temperature peak corresponds to an irreversible process accompanied by the oxidation of molybdenum with OH group on alumina of Bi2O3-Al2O3. It was found that the shoulder part of the high temperature decomposition d id not make an evolution of hydrogen although the oxidation of molybdenum with OH group generated hydrogen. From these results, Mo(CO)6 adsorbed on alumina of Bi2O3-Al2O3 is oxidized by the reaction with the OH group on it, but the surface. of Bi2O3 does not seem to have such OH groups. The metathesis of propylene was carried out on the Mo(CO) 6/Bi2O3Al2O3 catalyst prepared by the evacuation at various temperatures. The catalytic activit y markedly depends on the temperature of the evacuation, and the maximum activity was obtained by the evacuation at about 150°C. This fact results that Mo (CO)3 formed by the thermal decomposition is effective for the metathesis reaction.
