Molecular　oxygen　(O-2)　activation　is　a　critical　step　in　the　low-temperature　catalytic　oxidation　of　carbon　monoxide　(CO).　Photocatalysis　is　a　facile　way　to　activate　O-2　to　superoxide　radicals　under　mild　conditions.　Photothermal　catalysis,　which　integrates　the　photocatalysis　of　semiconductors　and　the　thermocatalysis　of　noble　metals,　has　arisen　as　an　appealing　strategy　to　achieve　low-temperature　catalytic　oxidation.　Here,　we　report　that　Pd/PdO/CeO2　shows　that　the　temperature　of　90%　CO　conversion　dropped　by　30　degrees　C-50　degrees　C　under　irradiation.　The　apparent　activation　energy　reduces　from　64.6　kJ.mol(-1)　to　44.6　kJ　.　mol(-1).　Pd/PdO/TiO2　and　Pd/PdO/Al2O3　are　prepared　and　compared　to　understand　the　underlying　mechanism.　The　results　reveal　that　photocatalysis　is　vital　in　lowering　the　apparent　activation　energy　besides　the　photothermal　effect.　The　photo-generated　electrons　promote　O-2　activation　to　generate　the　superoxide　anion.　The　hole　can　activate　the　adsorbed　CO　on　the　PdO.　These　active　species　are　beneficial　for　lowering　the　CO　oxidation　temperature.