Research On Synthesis Of Acetophenone By POM Liquid-phase Catalyzed Oxidation Of Ethylbenzene

Acetophenone is an important chemical raw materials and was producted by direct oxidation of ethylbenzene over O2 on industry,but existing disadvantages such as the conversion of low and by-products of many. Along with the global attention to environmental protection, HPC have been investigated extensively because of its high catalytic activity and selective, mild reaction conditions and anti-corrosion equipment as a green catalyst, Therefore, it has important research and industrial significance to develop their applied research in organic synthesis and catalytic field.This dissertation Taking ethylbenzene as raw materials,research the synthesis method of molybdovanadophosphate and their catalytic activity for ethylbenzene liquid-phase oxidation, speculate the reaction mechanism. The main progress and research results have been obtained as follows:1. Synthesize and characterize the molybdovanadophosphate over Dawson-typeA series of molybdovanadophosphate Co_(8-n)/2(Cpyr)_nP₂Mo₁₆V₂O₆₂(n=1,2…8, Cpyr=(C₁₆H₃₂C₅H₄N)⁺)Co_nH_9-2nP₂Mo₁₅V₃O₆₂(n=1-4) are synthesized andcharacterized by Atomic absorption spectrometry,Fourier transform infrared Spectro-scopy(FT-IR), X-ray diffraction(XRD)and thermal analysis(TG). Results show that Co_(8-n)/2(Cpyr)_nP₂–Mo₁₆V₂O₆₂,Co_nH_9-2nP₂Mo₁₅V₃O₆₂were found to exhibit Dawson structure, transition metals cobalt and organic groups have not entered the primary structure and hold only atthecation position.2.Catalytic Oxidation of ethylbenzene to acetophenone by Co_(8-n)/2(Cpyr)_nP₂Mo₁₆V₂O₆₂Taking TBHP as oxidant,Co_(8-n)/2(Cpyr)_nP₂Mo₁₆V₂O₆₂ as catalyst,Establish catalytic systems of ethylbenzene-Co2(Cpyr)4P₂Mo₁₆V₂O₆₂-TBHP and study the effects of reaction conditions.Experimental results show that Co2(Cpyr)4P₂Mo₁₆V₂O₆₂ paly highest catalytic activity and acetic acid is the best solvent ,the conversion of ethylbenzene was 80.9% and the yield of acetophenone was 73.2% under the conditions of the amount ofethylbenzene 25mmol, n(C₈H₁₀)/n(TBHP)=0.25, acetic10ml,Co₂(Cpyr)₄P₂Mo₁₆V₂O₆₂ Catalyst0.1mmol, reaction time 8h, temperature 80℃.3. Catalytic Oxidation of ethylbenzene to acetophenone by Co_nH_9-2nP₂Mo₁₅V₃O₆₂Taking H₂O₂ as oxidant, Co_nH_9-2nP₂Mo₁₅V₃O₆₂ as catalyst, Establish catalytic systems of ethylbenzene- Co_nH_9-2nP₂Mo₁₅V₃O₆₂- H₂O₂ and study the effects of reaction conditions.Experimental results show that Co₄HP₂Mo₁₅V₃O₆₂ paly highest catalytic activity and the conversion of ethylbenzene was 80.5% and the yield of acetophenone was 71.5% under the conditions of the amount of ethylbenzene 25mmol, acetic10ml, n(C₈H₁₀)/n(TBHP)=0.25 Co₂(Cpyr)₄P₂Mo₁₆V₂O₆₂catalyst 0.1mmol, reaction time 8h, the temperature 80℃.4. Catalytic Oxidation of ethylbenzene to acetophenone by supported molybdovanado -phosphoric cobalt heteropoly acid saltTaking H₂O₂ as oxidant, supported molybdovanadophosphoric cobalt heteropoly acid salt as catalyst and study the effects of reaction conditions. Experimental results show that HZSM-5 as carrier, loading of Co₄HP₂Mo₁₅V₃O₆₂was 30%,the conversion of was 82.21% and the yield of acetophenone was 55.75% under the conditions of the amount of ethylbenzene 25mmol, n(C₈H₁₀) / n(H₂O₂) = 0.125, m(Cat) / m(KBr) = 2/3, catalyst 0.4g ,reaction time 1h, the temperature 80℃.