A titania support with a large surface area was developed, which has a BET surface area of 380.5 m^2/g, four times that of a traditional titania support. The support was ultrasonically impregnated with 5 wt% vanadia. ...A titania support with a large surface area was developed, which has a BET surface area of 380.5 m^2/g, four times that of a traditional titania support. The support was ultrasonically impregnated with 5 wt% vanadia. A special heat treatment was used in the calcination to maintain the large surface area and high dispersion of vanadium species. This catalyst was compared to a common V2O5-TiO2 catalyst with the same vanadia loading prepared by a traditional method. The new catalyst has a surface area of 117.7 m^2/g, which was 38% higher than the traditional V2O5-TiO2 catalyst. The selective catalytic reduction（SCR） performance demonstrated that the new catalyst had a wider temperature window and better N2 selectivity compared to the traditional one. The NO conversion was 80% from 200 to 450 °C. The temperature window was 100 °C wider than the traditional catalyst. Raman spectra indicated that the vanadium species formed more V-O-V linkages on the catalyst prepared by the traditional method. The amount of V-O-Ti and V=O was larger for the new catalyst. Temperature programmed desorption of NH3, temperature programmed reduction by H2 and X-ray photoelectron spectroscopy results showed that its redox ability and total acidity were enhanced. The results are helpful for developing a more efficient SCR catalyst for the removal of NOx in flue gases.展开更多
A practical approach was introduced to study the inclusion mechanism of chlorine in high purity copper electrorefining from nitric acid system via cyclic voltammetry(CV) combined with electrodeposition experiments. Th...A practical approach was introduced to study the inclusion mechanism of chlorine in high purity copper electrorefining from nitric acid system via cyclic voltammetry(CV) combined with electrodeposition experiments. The CV curves display an obvious reduction peak of Cu Cl intermediate, which can provide an insight into the electrochemical behavior of this inclusion. Experimental results show that the increase of HNO3 concentration is favorable to reducing the quantity of chlorine inclusion although there is a slight decline in cathodic current efficiency. The optimum conditions for copper electrorefining in nitric acid system are HNO3 concentration in solution of 1-2 mol/L, moderate temperature of ~35 ℃ with current density not exceeding 25 m A/cm2. Based on the theoretical studies, an optimized copper electrorefining experiment was designed to simulate the industrial electrolysis, by which high purity copper can be obtained with chlorine inclusion less than 10 μg/g and current efficiency higher than 90%.展开更多
In a high concentration substrate medium, a heterotrophic bacterium with high removal efficiency of ammonium, named W1, was isolated from activated sludge of coking wastewater treatment facility. The bacterium was Gra...In a high concentration substrate medium, a heterotrophic bacterium with high removal efficiency of ammonium, named W1, was isolated from activated sludge of coking wastewater treatment facility. The bacterium was Gram-negative, rod-shaped, and identified preliminarily as Alcaligenes sp. according to its morphological and physiological properties and its 16S rRNA gene sequence analysis. In the high concentration ammonium medium (400 mg·L 1 4 NH -N), the effects of C source, N source, C/N ratio and initial pH of medium on ammonium removal were investigated in order to determine the optimal condition for strain W1. The maximum ammonium removal was around 95% in 4 days in an improved medium. The production of N 2 gas was examined in a closed system that was full of pure oxygen at the beginning. N 2 gas was detected in the system after 4 days of cultivation, which further testified that strain W1 has heterotrophic nitrification and aerobic denitrification abilities simultaneously.展开更多
The solubilities of the quinary system Na^＋ ,K^＋ ,Mg^2＋ //Cl ,NO 3 ^-H2O and its two quaternary subsystems, Na^＋ ,K^＋ ,Mg^2＋ //NO 3 -H2O and K^ ＋ ,Mg ^2＋ //Cl ,NO 3 ^-H2O,were studied by isothermal method at 2...The solubilities of the quinary system Na^＋ ,K^＋ ,Mg^2＋ //Cl ,NO 3 ^-H2O and its two quaternary subsystems, Na^＋ ,K^＋ ,Mg^2＋ //NO 3 -H2O and K^ ＋ ,Mg ^2＋ //Cl ,NO 3 ^-H2O,were studied by isothermal method at 25°C and their phase diagrams were plotted.In the equilibrium phase diagram of quaternary system Na^ ＋ ,K^ ＋ ,Mg ^2＋ //NO 3 ^-H2O, there are one invariant point,three univariant curves and three regions of crystallization with one salt：NaNO3, KNO3 and Mg（NO3）2·6H2O.In the equilibrium phase diagram of quaternary system K ^＋ ,Mg ^2＋ //Cl ,NO 3 ^-H2O,there are three invariant points,seven univariant curves and five regions of crystallization with one salt：KNO3,KCl, Mg（NO3）2·6H2O,MgCl2·6H2O and KCl·MgCl2·6H2O.In the equilibrium phase diagram of the quinary system Na ^＋ , K^ ＋ ,Mg ^2＋ //Cl ,NO 3^ -H2O,there are four invariant points,and seven regions of crystallization with one salt：NaCl, KCl,NaNO3,KCl·MgCl2·6H2O,KNO3,MgCl2·6H2O and Mg（NO3）2·6H2O.展开更多
2-Methyl-4-methoxyaniline （MMA） was synthesized by one-pot method through the hydrogenation and Bamberger rearrangement of o-nitrotoluene in methanol using acidic ionic liquid and 3% Pt/C as catalyst system. The eff...2-Methyl-4-methoxyaniline （MMA） was synthesized by one-pot method through the hydrogenation and Bamberger rearrangement of o-nitrotoluene in methanol using acidic ionic liquid and 3% Pt/C as catalyst system. The effects of ionic liquid type, dosage of ionic liquid and 3% Pt/C, reaction temperature and reaction pressure on o-nitrotoluene conversion and MMA selectivity were investigated. The results indicated that the imidazolium-based acidic ionic liquid which contains SO3H-functionalized cation showed higher selectivity to MMA than other acidic ionic liquids used in this work. Using 1-（propyl-3-sulfonate）-3-methylimidazolium hydrosulfate （[HSO3-pmim][HSO4]） as the acid catalyst, the selectivity to MMA was as high as 67.6% at 97.8% of o-nitrotoluene conversion. As 3% Pt/C increased from 0.01 g to 0.025 g, the selectivity to MMA decreased from 73.4% to 62.5%, because of the hydrogenation of intermediate o-methyl-phenylhydroxylamine to o-toluidine becoming more dominant. An increase in hydrogen pressure also had obviously dramatic effect in lowering the MMA selectivity. After easy separation from the products, the catalyst system could be reused at least 3 times.展开更多
Selective hydrogenation of chloronitrobenzene(CNB) to chloroaniline(CAN) catalyzed by water-soluble Ru/Pt bimetallic catalyst in an aqueous-organic biphasic system was studied. It was found that the catalytic activity...Selective hydrogenation of chloronitrobenzene(CNB) to chloroaniline(CAN) catalyzed by water-soluble Ru/Pt bimetallic catalyst in an aqueous-organic biphasic system was studied. It was found that the catalytic activity increased obviously due to the addition of platinum. Ru/Pt bimetallic catalysts exhibited a strong synergistic effect when the molar ratio of Pt was in the range of 5%—80%. Under the mild conditions including a temperature of 25 ℃, a hydrogen pressure of 1.0 MPa and a Pt molar ratio of 20%, the conversion of p-chloronitrobenzene(p-CNB) reached 99.9%, with the selectivity to p-chloroaniline(p-CAN) equating to 99.4%. The Ru/Pt catalyst also showed high activity and selectivity for the hydrogenation of other chloro- and dichloro-nitrobenzenes with different substituted positions. In addition, the catalyst can be recycled five times without significant loss of activity.展开更多
基金supported by the National Natural Science Foundation of China(21325731,21221004)the National High Technology Research and Development Program of China(863 Program)the State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex
文摘A titania support with a large surface area was developed, which has a BET surface area of 380.5 m^2/g, four times that of a traditional titania support. The support was ultrasonically impregnated with 5 wt% vanadia. A special heat treatment was used in the calcination to maintain the large surface area and high dispersion of vanadium species. This catalyst was compared to a common V2O5-TiO2 catalyst with the same vanadia loading prepared by a traditional method. The new catalyst has a surface area of 117.7 m^2/g, which was 38% higher than the traditional V2O5-TiO2 catalyst. The selective catalytic reduction（SCR） performance demonstrated that the new catalyst had a wider temperature window and better N2 selectivity compared to the traditional one. The NO conversion was 80% from 200 to 450 °C. The temperature window was 100 °C wider than the traditional catalyst. Raman spectra indicated that the vanadium species formed more V-O-V linkages on the catalyst prepared by the traditional method. The amount of V-O-Ti and V=O was larger for the new catalyst. Temperature programmed desorption of NH3, temperature programmed reduction by H2 and X-ray photoelectron spectroscopy results showed that its redox ability and total acidity were enhanced. The results are helpful for developing a more efficient SCR catalyst for the removal of NOx in flue gases.
基金Project(LY17B030009)supported by the Natural Science Foundation of Zhejiang Province,China。
文摘A practical approach was introduced to study the inclusion mechanism of chlorine in high purity copper electrorefining from nitric acid system via cyclic voltammetry(CV) combined with electrodeposition experiments. The CV curves display an obvious reduction peak of Cu Cl intermediate, which can provide an insight into the electrochemical behavior of this inclusion. Experimental results show that the increase of HNO3 concentration is favorable to reducing the quantity of chlorine inclusion although there is a slight decline in cathodic current efficiency. The optimum conditions for copper electrorefining in nitric acid system are HNO3 concentration in solution of 1-2 mol/L, moderate temperature of ~35 ℃ with current density not exceeding 25 m A/cm2. Based on the theoretical studies, an optimized copper electrorefining experiment was designed to simulate the industrial electrolysis, by which high purity copper can be obtained with chlorine inclusion less than 10 μg/g and current efficiency higher than 90%.
基金Supported by the National Natural Science Foundation of China (51078252)the International Cooperation Projects of Shanxi Province (2010081018)the Natural Science Foundation of Shanxi Province (2010011016-1)
文摘In a high concentration substrate medium, a heterotrophic bacterium with high removal efficiency of ammonium, named W1, was isolated from activated sludge of coking wastewater treatment facility. The bacterium was Gram-negative, rod-shaped, and identified preliminarily as Alcaligenes sp. according to its morphological and physiological properties and its 16S rRNA gene sequence analysis. In the high concentration ammonium medium (400 mg·L 1 4 NH -N), the effects of C source, N source, C/N ratio and initial pH of medium on ammonium removal were investigated in order to determine the optimal condition for strain W1. The maximum ammonium removal was around 95% in 4 days in an improved medium. The production of N 2 gas was examined in a closed system that was full of pure oxygen at the beginning. N 2 gas was detected in the system after 4 days of cultivation, which further testified that strain W1 has heterotrophic nitrification and aerobic denitrification abilities simultaneously.
基金Supported by the National Natural Science Foundation of China（20466003 20866008）
文摘The solubilities of the quinary system Na^＋ ,K^＋ ,Mg^2＋ //Cl ,NO 3 ^-H2O and its two quaternary subsystems, Na^＋ ,K^＋ ,Mg^2＋ //NO 3 -H2O and K^ ＋ ,Mg ^2＋ //Cl ,NO 3 ^-H2O,were studied by isothermal method at 25°C and their phase diagrams were plotted.In the equilibrium phase diagram of quaternary system Na^ ＋ ,K^ ＋ ,Mg ^2＋ //NO 3 ^-H2O, there are one invariant point,three univariant curves and three regions of crystallization with one salt：NaNO3, KNO3 and Mg（NO3）2·6H2O.In the equilibrium phase diagram of quaternary system K ^＋ ,Mg ^2＋ //Cl ,NO 3 ^-H2O,there are three invariant points,seven univariant curves and five regions of crystallization with one salt：KNO3,KCl, Mg（NO3）2·6H2O,MgCl2·6H2O and KCl·MgCl2·6H2O.In the equilibrium phase diagram of the quinary system Na ^＋ , K^ ＋ ,Mg ^2＋ //Cl ,NO 3^ -H2O,there are four invariant points,and seven regions of crystallization with one salt：NaCl, KCl,NaNO3,KCl·MgCl2·6H2O,KNO3,MgCl2·6H2O and Mg（NO3）2·6H2O.
基金Supported by the National Natural Science Foundation of China （21106134） and the Natural Science Foundation of Zlaejlang Province （Y4100671）.
文摘2-Methyl-4-methoxyaniline （MMA） was synthesized by one-pot method through the hydrogenation and Bamberger rearrangement of o-nitrotoluene in methanol using acidic ionic liquid and 3% Pt/C as catalyst system. The effects of ionic liquid type, dosage of ionic liquid and 3% Pt/C, reaction temperature and reaction pressure on o-nitrotoluene conversion and MMA selectivity were investigated. The results indicated that the imidazolium-based acidic ionic liquid which contains SO3H-functionalized cation showed higher selectivity to MMA than other acidic ionic liquids used in this work. Using 1-（propyl-3-sulfonate）-3-methylimidazolium hydrosulfate （[HSO3-pmim][HSO4]） as the acid catalyst, the selectivity to MMA was as high as 67.6% at 97.8% of o-nitrotoluene conversion. As 3% Pt/C increased from 0.01 g to 0.025 g, the selectivity to MMA decreased from 73.4% to 62.5%, because of the hydrogenation of intermediate o-methyl-phenylhydroxylamine to o-toluidine becoming more dominant. An increase in hydrogen pressure also had obviously dramatic effect in lowering the MMA selectivity. After easy separation from the products, the catalyst system could be reused at least 3 times.
基金the financial supports of the Natural Science Foundation of China(No.21303139)the Open Project of Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province(No.CSPC2013-1)+1 种基金the Key Fund Project of Educational Department of Sichuan Province(No.14ZA0126)the Doctoral Initiating Fund of China West Normal University(No.10B010)
文摘Selective hydrogenation of chloronitrobenzene(CNB) to chloroaniline(CAN) catalyzed by water-soluble Ru/Pt bimetallic catalyst in an aqueous-organic biphasic system was studied. It was found that the catalytic activity increased obviously due to the addition of platinum. Ru/Pt bimetallic catalysts exhibited a strong synergistic effect when the molar ratio of Pt was in the range of 5%—80%. Under the mild conditions including a temperature of 25 ℃, a hydrogen pressure of 1.0 MPa and a Pt molar ratio of 20%, the conversion of p-chloronitrobenzene(p-CNB) reached 99.9%, with the selectivity to p-chloroaniline(p-CAN) equating to 99.4%. The Ru/Pt catalyst also showed high activity and selectivity for the hydrogenation of other chloro- and dichloro-nitrobenzenes with different substituted positions. In addition, the catalyst can be recycled five times without significant loss of activity.
