Study on Catalytic Activities of Oxidized or Reduced Polycomponenet Noble Metals Auto-catalysts

Catalytic activities of oxidized Pt-Pd/Al2O3 and reduced Pt-Pd/Al2O3 catalysts,oxidized Pt-Rh-Pd/Al2O3 and reduced Pt-Rh-Pd/Al2O3 catalysts were studied with flow-system micro reactor.All these catalysts were characterized by TPD,XRD and TPR and their catalytic mechanisms were discussed.The results showed that oxidation activity of oxidized Pt-Pd/Al2O3 catalyst is superior to that of reduced Pt-Pd/Al2O3 catalyst,and they have the same catalytic mechanism.The oxidation activity of oxidized Pt-Rh-Pd/Al2O3 catalyst is not as good as that of reduced Pt-Rh-Pd/Al2O3 catalyst,which is attributed to their different catalytic mechanisms.Noble metals combined with oxygen are harmful to the reduction activities.