| The industrial grade multi-walled carbon nanotubes as catalyst, It was purified by liquidphase oxidation combined with ultrasound. Molybdophosphoric acid/MWCNT catalyst wasfabricated by dipping ethanol-MWCNT in the mixing solution of molybdophosphoric acid. Thecatalysts characterized by Fourier transform infrared spectrometer, X-ray diffraction structure.The catalytic activity of the MWCNT and the molybdophosphoric acid/MWCNT catalystswere tested through synthesis of butyl acetate, dimethyl oxalate and cyclohexanone1,2-propanediol ketals. The main contents are as follows:The orthogonal design was used to study the synthesis of butyl acetate, usingacetic acid and n-butanol as materials, industrial-grade multi-wall carbon nanotubepurred liquid oxide as catalyst. In the orthogonal experiment with three factors and fourlevels, the influence of the ratio alcohol to acid、catalyst dosage and the reaction time onthe esterification was discussed. When the ice acetic acid dosage is0.1mol, reactiontemperature120±2℃, the results of experiment indicates that the optimum conditions forthe ratio alcohol to acid is1.2, the amount of catalyst is1.0g, the reaction time is3.0h, the inversion ratio of ice acetic acid is68.22%; Synthesis of butyl acetate catalyzed bymulti-wall carbon nanotube supported molybdophosphoric acid. The optimized condition are asfollows: the amount of molybdophosphoric acid/multi-wall carbon nanotube is50％, the ratioof alcohol and acid1.2:1(based on the acetic acid is1.0mol), the amount of catalyst is1.0g,the reaction time is3.5h. Under the optimum conditions，and the inversion ratio of acetic acidreached99.69％.The industrial-grade multi-wall carbon nanotube was purified by liquid oxide, which ascatalysts for the dimethyl oxalate of oxalic acid with methanol, and water-strip benzene wasstudied. The products characterized by X-4digital micro melting point, FT-IR. The influence ofthe various factors on the conversion rate of oxalic acid was discussed. The synthesis conditionsof dimethyl oxalate are as follows: the ratio alcohol to acid is2.2:1, the water taker12.0ml ofbenzene, the amount of catalyst is2.0g, the temperature is about80-100°C, before dehydrationin the oxalic acid reaction for1.5hours, and the reaction time is2.5hours. In the optimizationsynthesis condition, the oxalic acid conversion rate is73.26percent. The carbon nanotube as anapplication prospects catalyst of esterification reaction is no corrosion of equipment, easy separation, no environment pollution, recycling.Synthesis of cyclohexanone1,2-propanediol ketals catalyzed by MWCNT and multi-wallcarbon nanotube supported molybdophosphoric acid. The optimum conditions have been found,that is, MWCNT as catalyst: molar ratio of1,2-propanediol to cyclohexanone is1.3:1(0.1molcyclohexanone), catalyst dosage is0.6g, cyclohexane is3.0ml, the reaction temperature is150-160oC, and the reaction time is45min. The yields of ketals can reach68.61%at theoptimized conditions; Multi-wall carbon nanotube supported molybdophosphoric acid ascatalyst the optimized conditions: It was found that the catalyst containing50%molybdophosphoric acid, n(1,2-propanediol)∶n (cyclohexanone) is1.3:1,0.3g of catalyst,cyclohexane is3.0ml, and the reaction time is45min, parallel was measured twice at theoptimized conditions, the average yield91.96%.Multi-wall carbon nanotubes could replace the concentrated sulfuric acid as a catalyst ofthe esterification reaction and acetal (ketone), compared to the catalyst with other catalysts havethe following characteristics: versatility of equipment, non-corrosive, easy product separation,recyclable repeated use, is a useful application of the future green esterification reaction andacetal (ketone) reaction catalyst; having a high catalytic activity compared with other carrier,both the carrier, but also the accelerator. Therefore show a better effect than the conventionalcatalysts. |
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