Photochemical oxidation of thiophene in n-octane/water extraction system using O2 as oxidant was studied. The reaction mechanism ofthiophene oxidation was proposed. Results obtained here can be used as the reference f...Photochemical oxidation of thiophene in n-octane/water extraction system using O2 as oxidant was studied. The reaction mechanism ofthiophene oxidation was proposed. Results obtained here can be used as the reference for the oxidative desulfurization of gasoline because thiophene is one of the main components containing sulfur in fluid catalytic cracking gasoline. Thiophene dissolved in n-octane was photodecomposed and removed into the water phase at ambient temperature and atmospheric pressure. A 500 W high-pressure mercury lamp （main wave length 365 nm, 0.22 kW/m） was used as light source for irradiation, and air was introduced by a gas pump to supply O2. Thiophene can be photo-oxidized to sulfone, oxalic acid, SO4^2-, and CO2. The desulfurization yield of thiophene in n-octane is 58.9% under photo-irradiation for 5 h under the conditions of air flow at 150 mL/min and V（water）：V（n-octane）=1：1. It can be improved to 92.3% by adding 0.15 g zeoliteartificial into 100 mL reaction system, which is the adsorbent for O2 and thiophene. And under such conditions, the photo-oxidation kinetics of thiophene with O2/zeoliteartificial is first-order with an apparent rate constant of 0.5047 h^-1 and a half-time of 1.37 h. The sulfur content can be depressed from 800 μL/L to less than 62 μL/L.展开更多
Amide ionic liquids （MLs）/L-proline synergistic catalyzed Mannich reactions of isovaleraldehyde, methyl ketones, and aromatic amines were carried out in moderate to high yields （ up to 96% ） and high stereo select...Amide ionic liquids （MLs）/L-proline synergistic catalyzed Mannich reactions of isovaleraldehyde, methyl ketones, and aromatic amines were carried out in moderate to high yields （ up to 96% ） and high stereo selectivities （ 〉99% e. e. ）. The products were easily isolated by extraction; and the catalyst system was readily recycled at least thrice without significant loss of efficiency. The scope of the substrates was studied and the interpretation of the manifest improvement of the reaction rates and enantio-selectivity of the novel catalyst system was speculated.展开更多
Photocatalytic activities of TiO2 and NaY zeolites-supported TiO2 were investigated with omethoate as a model pollutant.The physical and chemical states of NaY zeolite-supported TiO2 were evaluated via XRD,FTIR,BET an...Photocatalytic activities of TiO2 and NaY zeolites-supported TiO2 were investigated with omethoate as a model pollutant.The physical and chemical states of NaY zeolite-supported TiO2 were evaluated via XRD,FTIR,BET and SEM.Photodegradation of omethoate was studied with H2O2 as oxidant and TiO2 supported on NaY zeolite as photocatalyst.Parameters involved in the photo-catalysis of omethoate,i.e.,the calcination temperature of the photocatalyst,initial omethoate concentration,the amount of TiO2 loaded on NaY zeolite,photocatalyst dosage and H2O2 concentration were investigated in detail.The results show that TiO2/NaY zeolite prepared by means of sol-gel method exhibited a good photocatalytic activity for the degradation of omethoate.Optimum conditions included the calcination temperature of photocatalyst 550℃,initial omethoate concentration 500 mg/L,the amount of TiO2 loaded on NaY zeolite 35%（mass fraction）,the amount of photocatalyst 5 g/L,H2O2 concentration 30 mL/L and an irradiation time of 180 min.The removal of omethoate was up to 93%.Kinetics parameters of the photocatalytic degradation of omethoate were measured and calculated.The result shows the kinetics of photocatalytic degradation of omethoate is first-order.展开更多
A series of condensation reactions of unmodified ketones and aromatic aldehydes to prepare α,β-unsaturated carbonyl compounds by means of Aldol reactions in Bronsted acid ionic liquids（BAILs）was explored.1-Butyl-3...A series of condensation reactions of unmodified ketones and aromatic aldehydes to prepare α,β-unsaturated carbonyl compounds by means of Aldol reactions in Bronsted acid ionic liquids（BAILs）was explored.1-Butyl-3-methylimidazolium hydrogen sulphate（BMImHSO4）acting as an effective media and catalyst in aldol reactions was compared with other BAILs,with the advantages of high conversion and selectivity.The product was easily isolated and the left ionic liquid can be readily recovered and reused at least 3 times with almost the same efficiency.The scope and limitation of the present method were explored and the possible catalytic mechanism was speculated.展开更多
基金Science and Technology Development Planning Foundation of Jilin Province, China(No.20030405)
文摘Photochemical oxidation of thiophene in n-octane/water extraction system using O2 as oxidant was studied. The reaction mechanism ofthiophene oxidation was proposed. Results obtained here can be used as the reference for the oxidative desulfurization of gasoline because thiophene is one of the main components containing sulfur in fluid catalytic cracking gasoline. Thiophene dissolved in n-octane was photodecomposed and removed into the water phase at ambient temperature and atmospheric pressure. A 500 W high-pressure mercury lamp （main wave length 365 nm, 0.22 kW/m） was used as light source for irradiation, and air was introduced by a gas pump to supply O2. Thiophene can be photo-oxidized to sulfone, oxalic acid, SO4^2-, and CO2. The desulfurization yield of thiophene in n-octane is 58.9% under photo-irradiation for 5 h under the conditions of air flow at 150 mL/min and V（water）：V（n-octane）=1：1. It can be improved to 92.3% by adding 0.15 g zeoliteartificial into 100 mL reaction system, which is the adsorbent for O2 and thiophene. And under such conditions, the photo-oxidation kinetics of thiophene with O2/zeoliteartificial is first-order with an apparent rate constant of 0.5047 h^-1 and a half-time of 1.37 h. The sulfur content can be depressed from 800 μL/L to less than 62 μL/L.
基金the National Natural Science Foundation of China(No 20576026)State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology(No 200402)+2 种基金Science & Technology Office of Hebei Province(No 04213036)Foundation of HebeiUniversity of Science and Technology(No XL2006021)Environmental Engineering Key Subject of Hebei Province
文摘Amide ionic liquids （MLs）/L-proline synergistic catalyzed Mannich reactions of isovaleraldehyde, methyl ketones, and aromatic amines were carried out in moderate to high yields （ up to 96% ） and high stereo selectivities （ 〉99% e. e. ）. The products were easily isolated by extraction; and the catalyst system was readily recycled at least thrice without significant loss of efficiency. The scope of the substrates was studied and the interpretation of the manifest improvement of the reaction rates and enantio-selectivity of the novel catalyst system was speculated.
基金Supported by the Natural Science Foundation of Hebei Province,China(No.203364)
文摘Photocatalytic activities of TiO2 and NaY zeolites-supported TiO2 were investigated with omethoate as a model pollutant.The physical and chemical states of NaY zeolite-supported TiO2 were evaluated via XRD,FTIR,BET and SEM.Photodegradation of omethoate was studied with H2O2 as oxidant and TiO2 supported on NaY zeolite as photocatalyst.Parameters involved in the photo-catalysis of omethoate,i.e.,the calcination temperature of the photocatalyst,initial omethoate concentration,the amount of TiO2 loaded on NaY zeolite,photocatalyst dosage and H2O2 concentration were investigated in detail.The results show that TiO2/NaY zeolite prepared by means of sol-gel method exhibited a good photocatalytic activity for the degradation of omethoate.Optimum conditions included the calcination temperature of photocatalyst 550℃,initial omethoate concentration 500 mg/L,the amount of TiO2 loaded on NaY zeolite 35%（mass fraction）,the amount of photocatalyst 5 g/L,H2O2 concentration 30 mL/L and an irradiation time of 180 min.The removal of omethoate was up to 93%.Kinetics parameters of the photocatalytic degradation of omethoate were measured and calculated.The result shows the kinetics of photocatalytic degradation of omethoate is first-order.
基金Supported by National Natural Science Foundation of China(No.20576026)Environmental Engineering Key Subject of He-bei Province,China.
文摘A series of condensation reactions of unmodified ketones and aromatic aldehydes to prepare α,β-unsaturated carbonyl compounds by means of Aldol reactions in Bronsted acid ionic liquids（BAILs）was explored.1-Butyl-3-methylimidazolium hydrogen sulphate（BMImHSO4）acting as an effective media and catalyst in aldol reactions was compared with other BAILs,with the advantages of high conversion and selectivity.The product was easily isolated and the left ionic liquid can be readily recovered and reused at least 3 times with almost the same efficiency.The scope and limitation of the present method were explored and the possible catalytic mechanism was speculated.
