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Hydroformylation Of 1-octene Catalyzed By Cobalt Complex In The Thermoregulated Aqueous-organic Biphasic System With CoCO3 As Catalyst Precursor

Posted on:2016-09-09Degree:MasterType:Thesis
Country:ChinaCandidate:G D LiFull Text:PDF
GTID:2271330461476533Subject:Organic Chemistry
Abstract/Summary:PDF Full Text Request
Hydroformylation of. long-chain olefins (C>8) together with the subsequent hydrogenation of the aldehyde is an important industrial process to produce alcohols which can be used to manufacture plasticizers,soaps and detergents.To date,homogeneous process is still the most important one in the hydroformylation of long-chain olefins to produce alchohols.However,the catalyst/product separation is still a severe problem in the hydroformylation of long-chain olefins in homogeneous systems in industry.In our previous work, Thermoregulated phase-transfer catalysis(TRPTC) has been successfully applied in the rhodium-catalyzed hydroformylation of higher olefins in an aqueous/organic biphasic system. Recently, we have reported the hydroformylation of 1-octene based on Co2(CO)8 and some cobalt salt cobalt,such as cobalt acetate, cobalt(Ⅱ) acetylacetonate,cobalt chloride,in the biphasic system. In continuation, here we used a catalyst generating in situ from COCO3 as a catalyst precursor and L as ligand in hydroformylation of 1-octene.CoCO3 is much cheaper and easier to prepare compared and the reactivity is as high as that by Co2(CO)8 Ph2P(CH2CH2O)nMe.In this research, based on the existing work, ligand L [CH3 (OCH2CH2) nPPh2 (n≈16)] whose synthetic steps were improved and optimized was prepared by using double amount of starting materials.The yield of the ligand L was improved from 51.9% to 67%.Five insitu formed thermoregulated phase-transfer cobalt catalysts based on their cobalt catalyst precursors were employed in the hydroformylation of 1-octane. Each of them was characterized by IR spectras and UV-VIS spectras,which preliminary confirmed that the cobalt carbonyl phosphine complexes hydroformylation catalyst generated from COCO3 was the same with that from Co2(CO)8.At conditions such like T=170 ℃, L/Co=4/1, P (H2/ Co=2/1)=5 MPa, T=5 h, when COCO3 was used as catalyst precursor, according to the reaction results, yield of the carbonylation products was the highest (80.4%).The insitu formed thermoregulated phase-transfer cobalt catalysts based on COCO3 was used for the hydroformylation of 1-octene.The effect of reaction temperature, ratio of PH2/ PCO, syngas initial pressure, molar ratio of catalyst/substrate, reaction time, reaction temperature together with L/Co ratio on the reaction were investigated in detail. The effects of examination of the catalyst circulation use. Under the optimized conditions,Cat./Sub.= 1/100,L/Co=4, T=170℃, PH2/Pco=2/1, P=5 MPa,t=7 h, the conversion of 1-octene was 96.8%, the yield of carbonylation products was 81.9%, the n/iso ration was up to 3.7, nonanols were the main carbonylation products (Snonanals/Snonanols<0.01). After 4 times recycling,the catalyst still maintaining high catalytic activity, and the total TON value was up to 313. The average leaching of cobalt and phosphorus was 0.16% and 0.79% respectively.
Keywords/Search Tags:Thermoregulated Phase-transfer Catalysis, CoCO3, 1-octene, Hydroformylation
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