Abstract: The catalytic activities of the supported PdO catalysts were found to be dependenton the kind of the support as follows: CeO₂>ZrO₂>TiO₂>Al₂O₃>SnO₂>ZSM-5>SiO₂.The reduction state of PdO in the catalyst played an important role in the oxidation activityof the catalyst.PdO/CeO₂ was inferior to PdO/Al₂O₃ in heat-stability, but its activity for COoxidation was higher than PdO/Al₂O₃, after it had been calcinated at 1200 ℃ for 4h.

Key words: supported PdO catalyst, CO oxidation, temperature programmed method