Ultraviolet　(UV)　light　is　introduced　into　the　process　of　oxidizing　CO　over　the　TiO2　supported　Pt/Co-B　bicomponent　catalyst　(Pt/Co-B/TiO2).　It　is　found　that　UV　irradiation　can　promote　the　oxidation　of　CO　and　the　preferential　oxidation　of　CO　in　the　presence　of　H-2　over　Pt/Co-B/TiO2.　This　promoted　effect　of　UV　irradiation　can　also　occur　on　other　TiO2　supported　Pt　catalysts　but　not　on　the　non-TiO2　supported　Pt/Co-B　catalysts.　It　is　proposed　that　the　photogenerated　electrons　induced　by　the　photoexcitation　of　TiO2　can　transfer　to　the　Pt　surface,　resulting　in　the　increase　of　surface　electron　density　of　Pt　species.　This　further　promotes　the　adsorption　of　CO　and　its　activation　at　the　surface　Pt　species,　and　then　the　subsequent　oxidation　of　CO　over　Pt/Co-B/TiO2.　This　indicates　that　the　photoexciatation　behavior　of　TiO2　can　be　acted　as　an　electron　donator　to　promote　the　activity　of　the　Pt/Co　bicomponent　catalyst　for　oxidizing　CO.　(C)　2011　Elsevier　B.V.　All　rights　reserved.