SAPO-34 was synthesized with n-butylamine（BA） as a template for the first time.Crystallization temperature and initial Si amount were important factors leading to successful syntheses.Lamellar AlPO-kanemite tends to...SAPO-34 was synthesized with n-butylamine（BA） as a template for the first time.Crystallization temperature and initial Si amount were important factors leading to successful syntheses.Lamellar AlPO-kanemite tends to form as the major phase or as an impurity of SAPO-34 at lower crystallization temperatures,though a higher initial Si amount may offer a positive effect on the crystallization of SAPO-34 that mitigates the low temperature.Higher temperature（240℃） can effectively suppress the generation of lamellar materials and allow the synthesis of pure SAPO-34 with a wider range of Si incorporation.The crystallization processes at 200 and 240℃ were investigated and compared.We used the aminothermal method to synthesize SAPO-34-BA at 240℃ and also found n-propylamine is a suitable template for the synthesis of SAPO-34.The SAPO-34-BA products were characterized by many techniques.SAPO-34-BA has good thermal stability,crystallinity and porosity.BA remained intact in the crystals with ~1.8 BA molecule per chabazite cage.The catalytic performance of SAPO-34 was tested in the methanol amination reaction,which showed high methanol conversion and selectivity for methylamine plus dimethylamine under the conditions investigated,suggesting that this material is a good candidate for the synthesis of methylamines.展开更多
The catalytic elimination of nitrogen-containing volatile organic compounds(NVOCs)still encounters bottlenecks in NO_(x)formation and low N_(2)selectivity.Here,a series of Cu-promoted Ce-Zr mixed oxide catalysts were ...The catalytic elimination of nitrogen-containing volatile organic compounds(NVOCs)still encounters bottlenecks in NO_(x)formation and low N_(2)selectivity.Here,a series of Cu-promoted Ce-Zr mixed oxide catalysts were synthesized using a simple precipitation approach,and n-butylamine was adopted as the probe pollutant to evaluate their catalytic performance.The Ce Cu_(10%)ZrO_(x)catalyst exhibited the best catalytic activity,with 100%n-butylamine conversion and 90%N_(2)selectivity at 250℃.Concurrently,this sample also displayed good water resistance.A detailed characterization of the catalyst was performed through a series of experimental studies and theoretical calculations.The addition of Cu increased the redox property and promoted the production of oxygen vacancies,all of which were favorable for the greatest nbutylamine selective catalytic oxidation performance.The changes of oxygen vacancies over Ce Cu_(10%)ZrO_(x)in reaction process were studied by in situ Raman spectra.Moreover,in situ diffuse reflectance infrared Fourier transform spectra(DRIFTs)and theoretical calculations were employed to explore the reaction mechanism of n-butylamine selective oxidation.The high activity and selectivity of this catalyst confirm the practical feasibility of the selective oxidation of n-butylamine to CO_(2)and N_(2),and the exploration of the reaction mechanism provides new insights into the further design of catalysts.展开更多
Ⅰ. NTRODUCTIONIn order to explain the catalytic properties of zeolite HZSM-5, it is necessary to know the nature, number and strength distribution of acid sites of zeolite, and the temperature programmed desorption (...Ⅰ. NTRODUCTIONIn order to explain the catalytic properties of zeolite HZSM-5, it is necessary to know the nature, number and strength distribution of acid sites of zeolite, and the temperature programmed desorption (TPD) of ammonia or pyridine is one of the most commonly-used methods. Compared with ammonia (pK_b=4.75) and pyri-展开更多
Zirconium proline-N-methylphosphonate-phosphate (α-ZPMPP) was prepared in the presence of HF for the first time. The a-ZPMPP sample is highly crystallized with interlayer distance of 1.52 nm. The interlayer distance ...Zirconium proline-N-methylphosphonate-phosphate (α-ZPMPP) was prepared in the presence of HF for the first time. The a-ZPMPP sample is highly crystallized with interlayer distance of 1.52 nm. The interlayer distance of complex of α-ZPMPP with n-butylamine (α-ZPMPP-BA) is in 0.45 nm larger than that of α-ZPMPP. The α-ZPMPP possesses different intercalation behavior of host-vip compound from α-ZP.展开更多
The kinetics of SN2 reaction between phenacyl bromide and various amines in 12 different solvents were studied. Solvent effects on the rate of this reaction and free energy of activation, ΔG#, were interpreted by app...The kinetics of SN2 reaction between phenacyl bromide and various amines in 12 different solvents were studied. Solvent effects on the rate of this reaction and free energy of activation, ΔG#, were interpreted by applying the Abraham-Kamlet-Taft (AKT) equation. The solvent polarity (π1*), solvent hydrogen-bond basicity (β1) and Hildebrand cohesive density energy (δ2H) are those parameters which increase the rate constant and decrease ΔG#, while solvent hydrogen-bond acidity (α1) will have the compensatory effect. A comparison among obtained values of second rate constants, k2 for different amines in a given solvent indicates that the amine reactivities are highly dependent on their structures. The consequent decrease of the rate constant for different amines in any given solvent was found to be: primary > secondary > tertiary. This order results from steric effects of amines.展开更多
基金supported by the National Natural Science Foundation of China(21676262,21476228,21506207)the Key Research Program of Frontier Sciences of CAS(QYZDB-SSW-JSC040)~~
文摘SAPO-34 was synthesized with n-butylamine（BA） as a template for the first time.Crystallization temperature and initial Si amount were important factors leading to successful syntheses.Lamellar AlPO-kanemite tends to form as the major phase or as an impurity of SAPO-34 at lower crystallization temperatures,though a higher initial Si amount may offer a positive effect on the crystallization of SAPO-34 that mitigates the low temperature.Higher temperature（240℃） can effectively suppress the generation of lamellar materials and allow the synthesis of pure SAPO-34 with a wider range of Si incorporation.The crystallization processes at 200 and 240℃ were investigated and compared.We used the aminothermal method to synthesize SAPO-34-BA at 240℃ and also found n-propylamine is a suitable template for the synthesis of SAPO-34.The SAPO-34-BA products were characterized by many techniques.SAPO-34-BA has good thermal stability,crystallinity and porosity.BA remained intact in the crystals with ~1.8 BA molecule per chabazite cage.The catalytic performance of SAPO-34 was tested in the methanol amination reaction,which showed high methanol conversion and selectivity for methylamine plus dimethylamine under the conditions investigated,suggesting that this material is a good candidate for the synthesis of methylamines.
基金the R&D Program of Beijing Municipal Education Commission(No.KJZD20191443001)Beijing Municipal Science and Technology Commission(No.Z181100000118003)the Fundamental Research Funds for the Central Universities and Doctoral Research Start-up Fund Project of Taiyuan University of Science and Technology(No.20202053)。
文摘The catalytic elimination of nitrogen-containing volatile organic compounds(NVOCs)still encounters bottlenecks in NO_(x)formation and low N_(2)selectivity.Here,a series of Cu-promoted Ce-Zr mixed oxide catalysts were synthesized using a simple precipitation approach,and n-butylamine was adopted as the probe pollutant to evaluate their catalytic performance.The Ce Cu_(10%)ZrO_(x)catalyst exhibited the best catalytic activity,with 100%n-butylamine conversion and 90%N_(2)selectivity at 250℃.Concurrently,this sample also displayed good water resistance.A detailed characterization of the catalyst was performed through a series of experimental studies and theoretical calculations.The addition of Cu increased the redox property and promoted the production of oxygen vacancies,all of which were favorable for the greatest nbutylamine selective catalytic oxidation performance.The changes of oxygen vacancies over Ce Cu_(10%)ZrO_(x)in reaction process were studied by in situ Raman spectra.Moreover,in situ diffuse reflectance infrared Fourier transform spectra(DRIFTs)and theoretical calculations were employed to explore the reaction mechanism of n-butylamine selective oxidation.The high activity and selectivity of this catalyst confirm the practical feasibility of the selective oxidation of n-butylamine to CO_(2)and N_(2),and the exploration of the reaction mechanism provides new insights into the further design of catalysts.
文摘Ⅰ. NTRODUCTIONIn order to explain the catalytic properties of zeolite HZSM-5, it is necessary to know the nature, number and strength distribution of acid sites of zeolite, and the temperature programmed desorption (TPD) of ammonia or pyridine is one of the most commonly-used methods. Compared with ammonia (pK_b=4.75) and pyri-
文摘Zirconium proline-N-methylphosphonate-phosphate (α-ZPMPP) was prepared in the presence of HF for the first time. The a-ZPMPP sample is highly crystallized with interlayer distance of 1.52 nm. The interlayer distance of complex of α-ZPMPP with n-butylamine (α-ZPMPP-BA) is in 0.45 nm larger than that of α-ZPMPP. The α-ZPMPP possesses different intercalation behavior of host-vip compound from α-ZP.
文摘The kinetics of SN2 reaction between phenacyl bromide and various amines in 12 different solvents were studied. Solvent effects on the rate of this reaction and free energy of activation, ΔG#, were interpreted by applying the Abraham-Kamlet-Taft (AKT) equation. The solvent polarity (π1*), solvent hydrogen-bond basicity (β1) and Hildebrand cohesive density energy (δ2H) are those parameters which increase the rate constant and decrease ΔG#, while solvent hydrogen-bond acidity (α1) will have the compensatory effect. A comparison among obtained values of second rate constants, k2 for different amines in a given solvent indicates that the amine reactivities are highly dependent on their structures. The consequent decrease of the rate constant for different amines in any given solvent was found to be: primary > secondary > tertiary. This order results from steric effects of amines.
