Immobilizationof12-TungstophosphoricAcidonAlSBA-15andItsCatalyticActivityforAcetylation

？12-Tungstophosphoricheteropolyacid(TPA)withaKegginstructurewasintroducedintoAl-incorporatedmesoporousmolecularsieves(AlSBA-15)bytheincipientwetnessmethod.ThematerialswerecharacterizedbyX-raydiffraction,nitrogenadsorption,scanningelectronmicroscopy,UV-VisdiffusereflectanceandRamanspectroscopy,whichconfirmedtheKegginandmesoporestructure.Itscatalyticactivitywasevaluatedundersolvent-freeconditionsintheliquidphaseat333–383Kforthepropionylationofanisolewithpropionicanhydride.ThecatalystsusedwereAlSBA-15,10%,20%,and40%TPA/AlSBA-15,and20%TPA/MCM-48.Inthepropionylationofanisolewithpropionicanhydride,thesubstitutionoccurredpredominantlyattheparaposition.The20%TPA/AlSBA-15catalystgaveatotalproductyieldof48%with98%selectivitytowards4-methoxypropiophenone.Theregenerabilityofthecatalystwasalsostudiedandwasfoundtobeexcellent.