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Study On The Catalytic Oxidation Of Cyclohexanone To Adipic Acid Catalysed Over Supported Phosphotungstic Acid

Posted on:2010-01-05Degree:MasterType:Thesis
Country:ChinaCandidate:X N MaFull Text:PDF
GTID:2121360278961119Subject:Applied Chemistry
Abstract/Summary:PDF Full Text Request
In order to overcome the deficiency that heteropoly acid is water soluble and cannot be recycled, one kind of supported catalyst using phosohotungstic acid as active component and pseudo-boehmite modified by lanthanum as carrier was prepared. The catalytic oxidation performance was evaluated by the reaction of catalytic oxidation of cyclohexanone to adipic acid using 30% H2O2 as oxidant. In addition, the supported phosphotungstic acid catalyst was characterized by IR, XRD, NH3-TPD, SEM and BET to analyze the surface area, pore structure, acid intensity, dispersion state and granule morphology to further elucidate the nature of catalytic activity. The optimum prepared conditions were that the pseudo-boehmite carrier modified by 2% lanthanum nitrate was calcined at 400℃for 4 hours, and phosohotungstic acid (30% mass fraction of carrier) was calcined at 180℃for 16 hours, then the supported catalyst was activated at 180℃. The optimum reaction conditions were that n(H2O2)∶n(C6H10O)∶n(H3PO4)∶n(C6H10O4)=1276∶290∶298∶1, and reacted under 75℃for an hour, then 93℃for 7 hours. The yield of adipic acid was up to 92.6%. This catalyst had high supported strength and the total loss of active component was less than 15% after recycled for six runs. The supported catalyst could be separated and recycled easily after reaction. Hydrogen peroxide was an environmental friendly oxidant with no corrosion and water as the only by-product. Phosphoric acid as acid additive was nontoxic. The product adipic acid had high purity without recrystallization. So it was????onmental friendly route to synthesize adipic acid.
Keywords/Search Tags:Phosphotungstic Acid, Adipic Acid, Hydrogen Peroxide, Pseudo-boehmite, Catalytic Oxidation
PDF Full Text Request
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