In　this　study,　we　selected　zeolite　molecular　sieves　(TS-1　and　HZSM-5)　with　highly　dispersed　transition　metal　(Ti　or　Fe)　in　their　frameworks　and　TiO2　P25　as　photocatalysts　and　typical　gas　as　probe　molecules.　The　structure　and　crystallization,　specific　surface　area,　pore　size　distribution,　light　absorption　and　active　radical　species　were　characterized　by　X-ray　diffraction　(XRD),　Brunauer-Emmett-Teller　surface　area　(BET),　diffuse　reflectance　spectroscopy　(DRS)　and　electron　spin　resonance　spectroscopy　(ESR).　The　influences　of　the　intrinsic　structure,　adsorption　property　and　the　kind　of　active　sites　of　the　catalytic　materials　on　their　photocatalytic　behaviors　of　different　molecules　were　investigated.　The　emphases　were　placed　on　the　photocatalytic　conversion　of　hydrophobic　halohydrocarbons　and　hydrophilic　lower　alcohol　over　zeolite　molecular　sieves.　The　photocatalytic　reactions　were　performed　in　a　tubular　vessel　microreactor　operating　in　a　continuous-flow　mode　under　UV　irradiation.　Analysis　of　the　reactor　effluent　was　conducted　by　a　gas　chromatograph　(HP6890).　The　concentrations　of　gas　molecules　and　carbon　dioxide　were　determined　by　using　the　flame　ionization　detector　(FID)　and　thermal　conductivity　detector　(TCD),　respectively.　Under　UV　irradiation,　the　excited　state　between　the　isolated　and　highly　dispersed　Fe3+/Ti4+　and　bridging　oxygen　atom　can　activate　the　molecular　oxygen　into　superoxide　radical　via　the　surface　electron　transfer,　which　can　participate　in　the　subsequent　selective　oxidation　reactions.　Due　to　zeolites　with　excellent　adsorption　relative　to　their　unique　MFI　pore　structure,　active　sites　environment　and　the　separation　mechanism　of　photogenerated　holes　and　electrons,　these　resulted　that　TS-1　and　HZSM-5　zeolites　with　regular　pore　structure　of　molecular　dimensions　showed　good　degradation　rate　of　chloroform　(about　80%)　for　16　h,　obviously　higher　than　that　of　TiO2.　Also,　they　exhibited　excellent　selectivity　for　photocatalytic　oxidation　of　methanol　and　isopropanol　into　formaldehyde　and　acetone,　respectively.　This　is　different　from　TiO2　as　a　typical　representative　of　conventional　semiconductor　photocatalysts,　in　which　the　hydroxyl　radicals　with　strong　oxidation　were　produced　as　main　active　species　and　can　mineralize　the　organic　compounds　into　inorganic　small　molecules　completely.　This　study　provides　ideas　for　the　photocatalytic　transformation　of　small　organic　molecules　over　molecular　sieves　with　highly　dispersed　transition　metal.　©　2013　Shanghai　Institute　of　Organic　Chemistry,　Chinese　Academy　of　Sciences.