Studies On The Synthesis And Properties Of Catalyst For Sodium Thiomethoxide Preparing DMDS

Dimethyldisulfide is an important chemical raw material and it has perfect market prospects.In this dissertation,dimethyldisulfide was prepared by the method of methylmercaptide oxidation under the presence of catalyst.Studies two aspects on the new catalyst are synthesis and performance evaluation.In this dissertation,synthesized tetraminephthalocyanine cobalt and prepared activated carbon supported(AC-CoTAPc)and activated carbon loaded sulfonated phthalocyanine cobalt(AC-CoPcS).Ligand and metal complexe(CoL)and activated carbon supported aza crown ether metal complex(AC-CoL)have been synthesized.(L=1,4,10,13-tetroxa-7,16-diazacyloocatadecane).The synthesized catalyst was characterized by elemental analyzer,ultraviolet spectrometer,infrared spectrometer and X-ray electron spectroscopy.As for activated carbon loaded sulfonated phthalocyanine cobalt,we studed reaction parameters such as temperature,pressure,reaction time,catalyst dosage,repeatable use of catalysts for the influence methyl mercaptan conversion,dimethylsulfide yield and purity in order to evaluation the performance of the catalyst.A novel catalytic system that metal complexs(CoL)as methyl mercaptan oxidation was proposed and the performance of metal complexs(CoL)was studied by Preparation of Dimethyldisulfide by catalytic oxidation of sodium methoxylate.The catalytic performance of free catalyst and activated carbon supported catalyst were evaluated by catalytic oxidation of sodium methoxylate.The energy of HSCH3 around four kinds of free catalyst was calculated and analyzed.The following important results obtained are as follows:(1)The metal phthalocyanine derivative and the tetraoxazacapentane metal complexs(CoL)are easily dissolved in dimethyldisulfide,the catalyst and products can not be separated well so that product needs extra decolorization.The catalyst after activated carbon loading can effectively achieve the separation of the catalyst and the product,the purity of dimethyldisulfide(DMDS)is 100%.(2)For the system of AC-CoTAPc catalytic oxidation of sodium methyl mercaptan.When the solution of sodium methanethiolate(18%)was 450 g,We come to the conclusion that the optimum amount of catalyst is 0.2g,the optimum reaction temperature is 65?,the optimum reaction time is 60 min,the optimum oxygen pressure is 0.9MPa,the catalyst used seven times DMDS yield reduced to 14.8%.In the optimal conditions,the yield of DMDS reached 87.4%,and the conversion of sodium methanethiol reached 98.1%.The purity of the product DMDS was 100%.(3)For the system of AC-CoPcS catalytic oxidation of sodium methyl mercaptan.When the solution of sodium methanethiolate(18%)was 450 g,We come to the conclusion that the optimum amount of catalyst is 0.4g,the optimum reaction temperature is 65?,the optimum reaction time is 60 min,the optimum oxygen pressure is 0.9MPa,the catalyst used seven times DMDS yield reduced to 8%.In the optimal conditions,the yield of DMDS reached 86.8%,and the conversion of sodium methanethiol reached 98.7%.The purity of the product DMDS was 100%.(4)For the system of activated carbon supported aza crown ether metal complex(AC-CoL)catalytic oxidation of sodium methyl mercaptan.When the solution of sodium methanethiolate(18%)was 450 g,We come to the conclusion that the optimum amount of catalyst is 0.2g,the optimum reaction temperature is 65?,the optimum reaction time is60 min,the optimum oxygen pressure is 0.7MPa,catalyst is deactivated after 5 times.In the optimal conditions,the yield of DMDS reached 76.7%,and the conversion of sodium methanethiol reached 97.3%.The purity of the product DMDS was 100%.(5)Based on the results of the energy calculation about HSCH3 around four kinds of free catalyst,the catalytic activity of free aza crown ether metal complex(CoL)is better than that of the tetraaminophthalocyanine cobalt(CoTAPc)and the tetrasulfonic acid phthalocyanine cobalt(CoPcS)Which is consistent with the experimental conclusion.