This study demonstrates the design and application of a novel high temperature rotatory apparatus for insitu synchrotron X-ray diffraction studies of molten salts,facilitating investigation into the interaction betwee...This study demonstrates the design and application of a novel high temperature rotatory apparatus for insitu synchrotron X-ray diffraction studies of molten salts,facilitating investigation into the interaction between various structural materials and molten salts.The apparatus enables accurate detection of every phase change during hightemperature experiments,including strong reaction processes like corrosion.Molten salts,such as chlorides or fluo⁃rides,together with the structure materials,are inserted into either quartz or boron nitride capillaries,where X-ray diffraction pattern can be continuously collected,as the samples are heated to high temperature.The replacement re⁃action,when molten ZnCl2 are etching Ti3AlC2,can be clearly observed through changes in diffraction peak intensity as well as expansion in c-axis lattice parameter of the hexagonal matrix,due to the larger atomic number and ionic ra⁃dius of Zn2+.Furthermore,we investigated the high-temperature corrosion process when GH3535 alloy is in FLiNaK molten salt,and can help to optimize its stability for potential applications in molten salt reactor.Additionally,this high temperature apparatus is fully compatible with the combined usage of X-ray diffraction and Raman technique,providing both bulk and surface structural information.This high temperature apparatus has been open to users and is extensively used at BL14B1 beamline of the Shanghai Synchrotron Radiation Facility.展开更多
Chemical Manganese Dioxide （CMD） was prepared by an alkali-oxidation method. There are several virtues to this environmental friendly and clean process, including the nontoxic and harmless reagents and products, eas...Chemical Manganese Dioxide （CMD） was prepared by an alkali-oxidation method. There are several virtues to this environmental friendly and clean process, including the nontoxic and harmless reagents and products, easy operations, no pollutants, easily obtained raw materials and moderate reaction conditions. The synthesized manganese dioxide was characterized by XRD and SEM. The particles were small, consisting primarily of α-MnO2 and γ-MnO2. Experimental results showed that the optimum conditions were： MnSOa.H20 to NaOH ratio, 1.0：2.4; catalyst concentration （catalyst TF-2）, 6% of the MnSO4; initial solution pH, 11; reaction time and temperature, 20 min and 80 ℃; air flow, 0.20 m3/h; and, agitation rate, 700 r/rain. The conversion of MnSO4 can exceed 80% under these optimum conditions.展开更多
X-ray diffraction （XRD） was used to study the structure of the organic crystallite unit （La, Lo doo2） in coals collected from Henan and Shanxi Provinces. XRD patterns of coal were collected in a step-scan mode （0...X-ray diffraction （XRD） was used to study the structure of the organic crystallite unit （La, Lo doo2） in coals collected from Henan and Shanxi Provinces. XRD patterns of coal were collected in a step-scan mode （0.1 °/step） over an angular range of 2-90° （20）, allowing 8 s at each step. The structure of the crystallite unit was determined from the Scherrer equation and peak parameters deduced from whole pattern fitting. The results show that the structure of the crystallite unit in coal is mainly controlled by the coal rank. As the coal rank increases the average diameter of a coal crystallite unit （La） increases, the interlayer spacing （doo2） decreases slightly, and the average height of a coal crystallite unit （Lc） increases at first but then decreases. A new diffraction peak from the crystallite unit in coal was found at a low scattering angle in the XRD pattern （2-10~）. This suggests a structure with an inter-layer spacing from 1.9 to 2.8 nm exists in coal crystallites.展开更多
In order to discuss the geochemical characteristic of REEs （rare earth elements） and their geological application, we measured the contents of rare earth elements, trace elements and minerals of 29 Lopingian （Late ...In order to discuss the geochemical characteristic of REEs （rare earth elements） and their geological application, we measured the contents of rare earth elements, trace elements and minerals of 29 Lopingian （Late Permian） mudstone samples in Panxian county, carrying out ICP-MS and XRD analysis. The results show that the amount of REEs （185.56-729.46 ×10-6） is high. The ratios of w（LREE）/w（HREE） （6.84- 13.86） and W（La）N/w（Yb）N （1.01-3.02） show clear differentiation of LREEs and HREEs. ZREE has a significantly or critically positive correlation with lithophile elements Th, Nb, Ta, Ti, Ca, Sc, Cs, Zr, Hf, Sr, Be and chaicophile element Zn, a critically negative correlation with siderophile element Fe and a slightly positive correlation with illite, illite smectite mixed layers and siderite. REEs originate mainly from terrigenous minerals, in an inorganic phase, Source rocks of our samples consist of Emeishan basalt and a small part of sedimentary rocks, as suggested by the distribution patterns of REEs and w（∑REE）- w（La）/w（Yb） diagram. Moreover, abnormal surfaces near the sequence boundaries （SB2, SB3, SB4） are related wiLth the boundaries, identified by geochemical characteristics of the REEs, such as ∑REE. w（LREE）/w（HREE）, Eu/Eu＊ and Ceanom.展开更多
The chemical structure of heavy oil fractions obtained by liquid-solid adsorption chromatography was character-ized by 1 H nuclear magnetic resonance and X-ray diffraction.The molecular weight and molecular formula of...The chemical structure of heavy oil fractions obtained by liquid-solid adsorption chromatography was character-ized by 1 H nuclear magnetic resonance and X-ray diffraction.The molecular weight and molecular formula of asphaltene molecules were estimated by combining 1 H nuclear magnetic resonance and X-ray diffraction analyses,and were also ob-tained from vapor pressure osmometry and elemental analysis.Heteroatoms,such as S,N,and O atoms,were considered in the construction of average molecular structure of heavy oils.Two important structural parameters were proposed,including the number of alkyl chain substituents to aromatic rings and the number of total rings with heteroatoms.Ultimately,the av-erage molecular structures of polycyclic aromatics,heavy resins and asphaltene molecules were constructed.The number of α-,β-,γ-,and aromatic hydrogen atoms of the constructed average molecular structures fits well with the number of hydro-gen atoms derived from the experimental spectral data.展开更多
Exo-tetrahydrodicyclopentadiene （exo-TCD） is an important high-energy fuel. Silicotungstic acid （SiW） immobilized on H-type β zeolite （Hβ） at room temperature were used to prepare the Hβ zeolite catalysts wit...Exo-tetrahydrodicyclopentadiene （exo-TCD） is an important high-energy fuel. Silicotungstic acid （SiW） immobilized on H-type β zeolite （Hβ） at room temperature were used to prepare the Hβ zeolite catalysts with different SiW contents. Catalytic performances of the catalysts were investigated during the preparation of exo-TCD via isomerization of endo-tetrahydrodicyclopentadiene （endo-TCD）. The properties of catalysts were characterized by XRD, temperature pro- grammed desorption of ammonia （NHa-TPD）, FT-IR, and N2-adsorption techniques. SiW was highly dispersed on the surface of Hβ zeolite, and the 10% SiW/Hβ zeolite catalyst had the highest amount of weak acidity among all SiW/Hβ zeolite catalysts. The influence of different factors on isomerization reaction was investigated. At a reaction temperature of 240 ℃, a n（cyclohexane） / n（endo-TCD） ratio of 10, a m（catalyst）/m（endo-TCD） ratio of 0.3, an initial pressure of 1.0 MPa, and a reaction time of 1.5 h in the presence of 10% SiW/Hβ catalyst calcined at 400 ℃, the conversion of endo-TCD reached up to 92.0%, with the yield of exo-TCD equating to 51.0%.展开更多
A type of visible light photocatalyst Bi2WO6 was prepared from Bi(NO3)3.5H2O and Na2WO4.2H2O by means of hydrothermal method and was characterized by UV-vis diffuse reflectance spectrometry and XRD.Oxidative desulfuri...A type of visible light photocatalyst Bi2WO6 was prepared from Bi(NO3)3.5H2O and Na2WO4.2H2O by means of hydrothermal method and was characterized by UV-vis diffuse reflectance spectrometry and XRD.Oxidative desulfurization via photocatalysis was investigated using thiophene dissolved in octane as the model compound,with hydrogen peroxide used as the oxidant.The effects of hydrogen peroxide mass fraction,irradiation time,dosage of photocatalyst Bi2WO6 on the desulfurization efficiency were also investigated.Under suitable conditions,the desulfurization rate of model compound reached over 70%.展开更多
Two series of molybdenum-containing MCM-41 catalysts were prepared for oxidative desulfurization ofdibenzothiophene （DBT） using t-butylhydroperoxide （TBHP） as the oxidant. The electronic properties, pore dimension...Two series of molybdenum-containing MCM-41 catalysts were prepared for oxidative desulfurization ofdibenzothiophene （DBT） using t-butylhydroperoxide （TBHP） as the oxidant. The electronic properties, pore dimension and hydrophilic properties of the catalysts were studied by XRD, BET, and 1R spectrometry. The Mo-Al2O3 catalyst and TiMCM-3% were also studied for comparison. The two series of MCM-41 zeolite with MoO3 in the framework or impregnated on the surface exhibited considerable activities at low MoO3 content and both were faxbetter than the Mo-Al2O3 catalyst, but had lower activities as compared to the TiMCM-3% catalyst. The catalysts with the highest activity were evaluated in a fixed-bed reactor. The concentration of DBT in model diesel upon oxidative desulfurization was successfully reduced from 5000 ppm to less than 150 ppm, but the catalysts were deactivated very fast. The probable reason was the high affinity of DBTO2 to the MCM-41 skeleton, especially to MoO3. The catalysts could restore most of its original activity by treating with alcohol.展开更多
To prepare potassium titanate catalyst, a novel citrate acid complex-combustion method using CH3COOK and Ti（OC4H9）4 as raw materials was developed. The crystalline phase and surface morphology of K2Ti205 were invest...To prepare potassium titanate catalyst, a novel citrate acid complex-combustion method using CH3COOK and Ti（OC4H9）4 as raw materials was developed. The crystalline phase and surface morphology of K2Ti205 were investigated by X-ray diffraction （XRD）, field emission scanning electron microscope （FE-SEM） and transmission electron microscope （TEM）. The impact of some factors, such as the type of contact between K2Ti205 and soot, the content of water vapor and SO2 in exhaust, and the repeated use on catalytic activity of K2Ti205 were studied by temperature programmed reaction （TPR）. A comparison between the new method and the reported ones on catalytic activity of potassium titanate was investigated. The results showed that K2Ti205 had high catalytic activity and good stability.展开更多
The target products were prepared by homogeneous precipitation method using SDS and PEG 800, respectively, as surfactant at a reaction temperature of 95 ℃ for 3 h, followed by calcination at 400 ~C for 3 h. The sampl...The target products were prepared by homogeneous precipitation method using SDS and PEG 800, respectively, as surfactant at a reaction temperature of 95 ℃ for 3 h, followed by calcination at 400 ~C for 3 h. The samples were charac- terized and analyzed by XRD, SEM, FTIR and zeta potential measurements. The products were modified with different sur- factants to improve their dispersion stability, both the amount and the best zeta potential values of which were identified in this work. The surface-modified nano-particles were added at a mass fraction of 1.0%, 2.0%, 3.0%, and 4.0%, respectively, into the base oil. It was showed that the additive in base oil has good oil solubility without detectable corrosion of copper stripe, and had excellent behavior in terms of anti-wear performance and lower friction coefficient.展开更多
K2Ti2O5 and LixK2-xTi2O5 samples with varying K contents （x=0.125, 0.15, 0.3）, targeted on removal of two main environmental pollutants： PM and NOx, were synthesized by the solid state method using TiO2, KNO3 and L...K2Ti2O5 and LixK2-xTi2O5 samples with varying K contents （x=0.125, 0.15, 0.3）, targeted on removal of two main environmental pollutants： PM and NOx, were synthesized by the solid state method using TiO2, KNO3 and LiOH-H2O as starting materials and were characterized by X-ray diffractometry, scanning electron microscopy, and BET. The catalytic activity of titanate catalysts on PM oxidation was evaluated using the temperature programmed oxidation （TPO） method. The test results showed that the perovskite structure of K2Ti205 was still retained after doping a small amount of Li, and the catalytic performance of LixK2-xTi2O5 had been improved significantly compared with that of K2Ti2O5. Li0.15K1.85Ti205 catalyst had the highest catalytic activity with an ignition temperature of 210℃ and a peak temperature of 290℃. The catalytic activity of both K2Ti2O5 and LixK2-xTi2O5 under intimate contact was higher than that under loose contact. When the exhaust gas flow rate was around 100 mL/min, the catalyst samples showed a highest activity. The Li doped K2Ti2O5 could be an excellent candidate for PM oxidation due to its high oxidation activity, water stability, resistance to sulfur poisoning and economical advantages.展开更多
基金CAS Photon Science Research Center for Carbon DioxideCAS President’s International Fellowship Initiative(2024PVA0097)+1 种基金National Key Research and Development Program of China(2017YFA0403000,2017YFA0402800)National Natural Science Foundation of China(U1932201,U1732121)。
文摘This study demonstrates the design and application of a novel high temperature rotatory apparatus for insitu synchrotron X-ray diffraction studies of molten salts,facilitating investigation into the interaction between various structural materials and molten salts.The apparatus enables accurate detection of every phase change during hightemperature experiments,including strong reaction processes like corrosion.Molten salts,such as chlorides or fluo⁃rides,together with the structure materials,are inserted into either quartz or boron nitride capillaries,where X-ray diffraction pattern can be continuously collected,as the samples are heated to high temperature.The replacement re⁃action,when molten ZnCl2 are etching Ti3AlC2,can be clearly observed through changes in diffraction peak intensity as well as expansion in c-axis lattice parameter of the hexagonal matrix,due to the larger atomic number and ionic ra⁃dius of Zn2+.Furthermore,we investigated the high-temperature corrosion process when GH3535 alloy is in FLiNaK molten salt,and can help to optimize its stability for potential applications in molten salt reactor.Additionally,this high temperature apparatus is fully compatible with the combined usage of X-ray diffraction and Raman technique,providing both bulk and surface structural information.This high temperature apparatus has been open to users and is extensively used at BL14B1 beamline of the Shanghai Synchrotron Radiation Facility.
基金National Natural Science Foundation of China (No50704036)the Natural Science Foundation of Hunan Province (No08JJ3027) for their financial support
文摘Chemical Manganese Dioxide （CMD） was prepared by an alkali-oxidation method. There are several virtues to this environmental friendly and clean process, including the nontoxic and harmless reagents and products, easy operations, no pollutants, easily obtained raw materials and moderate reaction conditions. The synthesized manganese dioxide was characterized by XRD and SEM. The particles were small, consisting primarily of α-MnO2 and γ-MnO2. Experimental results showed that the optimum conditions were： MnSOa.H20 to NaOH ratio, 1.0：2.4; catalyst concentration （catalyst TF-2）, 6% of the MnSO4; initial solution pH, 11; reaction time and temperature, 20 min and 80 ℃; air flow, 0.20 m3/h; and, agitation rate, 700 r/rain. The conversion of MnSO4 can exceed 80% under these optimum conditions.
基金supported in part by Program for New Century Excellent Talents in University of China (No. NCET-10-0133)Innovation Scientists and Technicians Troop Construction Projects of Henan Province (No. 114100510004)
文摘X-ray diffraction （XRD） was used to study the structure of the organic crystallite unit （La, Lo doo2） in coals collected from Henan and Shanxi Provinces. XRD patterns of coal were collected in a step-scan mode （0.1 °/step） over an angular range of 2-90° （20）, allowing 8 s at each step. The structure of the crystallite unit was determined from the Scherrer equation and peak parameters deduced from whole pattern fitting. The results show that the structure of the crystallite unit in coal is mainly controlled by the coal rank. As the coal rank increases the average diameter of a coal crystallite unit （La） increases, the interlayer spacing （doo2） decreases slightly, and the average height of a coal crystallite unit （Lc） increases at first but then decreases. A new diffraction peak from the crystallite unit in coal was found at a low scattering angle in the XRD pattern （2-10~）. This suggests a structure with an inter-layer spacing from 1.9 to 2.8 nm exists in coal crystallites.
基金supported by the Key Program of the National Natural Science Foundation of China (No. 40730422)
文摘In order to discuss the geochemical characteristic of REEs （rare earth elements） and their geological application, we measured the contents of rare earth elements, trace elements and minerals of 29 Lopingian （Late Permian） mudstone samples in Panxian county, carrying out ICP-MS and XRD analysis. The results show that the amount of REEs （185.56-729.46 ×10-6） is high. The ratios of w（LREE）/w（HREE） （6.84- 13.86） and W（La）N/w（Yb）N （1.01-3.02） show clear differentiation of LREEs and HREEs. ZREE has a significantly or critically positive correlation with lithophile elements Th, Nb, Ta, Ti, Ca, Sc, Cs, Zr, Hf, Sr, Be and chaicophile element Zn, a critically negative correlation with siderophile element Fe and a slightly positive correlation with illite, illite smectite mixed layers and siderite. REEs originate mainly from terrigenous minerals, in an inorganic phase, Source rocks of our samples consist of Emeishan basalt and a small part of sedimentary rocks, as suggested by the distribution patterns of REEs and w（∑REE）- w（La）/w（Yb） diagram. Moreover, abnormal surfaces near the sequence boundaries （SB2, SB3, SB4） are related wiLth the boundaries, identified by geochemical characteristics of the REEs, such as ∑REE. w（LREE）/w（HREE）, Eu/Eu＊ and Ceanom.
基金the funding of the National Basic Research Program of China (Grant No.2006CB202505)
文摘The chemical structure of heavy oil fractions obtained by liquid-solid adsorption chromatography was character-ized by 1 H nuclear magnetic resonance and X-ray diffraction.The molecular weight and molecular formula of asphaltene molecules were estimated by combining 1 H nuclear magnetic resonance and X-ray diffraction analyses,and were also ob-tained from vapor pressure osmometry and elemental analysis.Heteroatoms,such as S,N,and O atoms,were considered in the construction of average molecular structure of heavy oils.Two important structural parameters were proposed,including the number of alkyl chain substituents to aromatic rings and the number of total rings with heteroatoms.Ultimately,the av-erage molecular structures of polycyclic aromatics,heavy resins and asphaltene molecules were constructed.The number of α-,β-,γ-,and aromatic hydrogen atoms of the constructed average molecular structures fits well with the number of hydro-gen atoms derived from the experimental spectral data.
文摘Exo-tetrahydrodicyclopentadiene （exo-TCD） is an important high-energy fuel. Silicotungstic acid （SiW） immobilized on H-type β zeolite （Hβ） at room temperature were used to prepare the Hβ zeolite catalysts with different SiW contents. Catalytic performances of the catalysts were investigated during the preparation of exo-TCD via isomerization of endo-tetrahydrodicyclopentadiene （endo-TCD）. The properties of catalysts were characterized by XRD, temperature pro- grammed desorption of ammonia （NHa-TPD）, FT-IR, and N2-adsorption techniques. SiW was highly dispersed on the surface of Hβ zeolite, and the 10% SiW/Hβ zeolite catalyst had the highest amount of weak acidity among all SiW/Hβ zeolite catalysts. The influence of different factors on isomerization reaction was investigated. At a reaction temperature of 240 ℃, a n（cyclohexane） / n（endo-TCD） ratio of 10, a m（catalyst）/m（endo-TCD） ratio of 0.3, an initial pressure of 1.0 MPa, and a reaction time of 1.5 h in the presence of 10% SiW/Hβ catalyst calcined at 400 ℃, the conversion of endo-TCD reached up to 92.0%, with the yield of exo-TCD equating to 51.0%.
基金support provided by the Shaanxi Provincial Education Project (09JK816)
文摘A type of visible light photocatalyst Bi2WO6 was prepared from Bi(NO3)3.5H2O and Na2WO4.2H2O by means of hydrothermal method and was characterized by UV-vis diffuse reflectance spectrometry and XRD.Oxidative desulfurization via photocatalysis was investigated using thiophene dissolved in octane as the model compound,with hydrogen peroxide used as the oxidant.The effects of hydrogen peroxide mass fraction,irradiation time,dosage of photocatalyst Bi2WO6 on the desulfurization efficiency were also investigated.Under suitable conditions,the desulfurization rate of model compound reached over 70%.
文摘Two series of molybdenum-containing MCM-41 catalysts were prepared for oxidative desulfurization ofdibenzothiophene （DBT） using t-butylhydroperoxide （TBHP） as the oxidant. The electronic properties, pore dimension and hydrophilic properties of the catalysts were studied by XRD, BET, and 1R spectrometry. The Mo-Al2O3 catalyst and TiMCM-3% were also studied for comparison. The two series of MCM-41 zeolite with MoO3 in the framework or impregnated on the surface exhibited considerable activities at low MoO3 content and both were faxbetter than the Mo-Al2O3 catalyst, but had lower activities as compared to the TiMCM-3% catalyst. The catalysts with the highest activity were evaluated in a fixed-bed reactor. The concentration of DBT in model diesel upon oxidative desulfurization was successfully reduced from 5000 ppm to less than 150 ppm, but the catalysts were deactivated very fast. The probable reason was the high affinity of DBTO2 to the MCM-41 skeleton, especially to MoO3. The catalysts could restore most of its original activity by treating with alcohol.
基金the financial supports provided for this research by the Education Department of Liaoning Province of China(No.2009T061)the Ministry of Education of China(No.[2010]1561)
文摘To prepare potassium titanate catalyst, a novel citrate acid complex-combustion method using CH3COOK and Ti（OC4H9）4 as raw materials was developed. The crystalline phase and surface morphology of K2Ti205 were investigated by X-ray diffraction （XRD）, field emission scanning electron microscope （FE-SEM） and transmission electron microscope （TEM）. The impact of some factors, such as the type of contact between K2Ti205 and soot, the content of water vapor and SO2 in exhaust, and the repeated use on catalytic activity of K2Ti205 were studied by temperature programmed reaction （TPR）. A comparison between the new method and the reported ones on catalytic activity of potassium titanate was investigated. The results showed that K2Ti205 had high catalytic activity and good stability.
基金supported by the Liaoning Provincial Office of Education for Innovation Team (2006T001)Liaoning Province of Key Laboratory Project (2008403001)
文摘The target products were prepared by homogeneous precipitation method using SDS and PEG 800, respectively, as surfactant at a reaction temperature of 95 ℃ for 3 h, followed by calcination at 400 ~C for 3 h. The samples were charac- terized and analyzed by XRD, SEM, FTIR and zeta potential measurements. The products were modified with different sur- factants to improve their dispersion stability, both the amount and the best zeta potential values of which were identified in this work. The surface-modified nano-particles were added at a mass fraction of 1.0%, 2.0%, 3.0%, and 4.0%, respectively, into the base oil. It was showed that the additive in base oil has good oil solubility without detectable corrosion of copper stripe, and had excellent behavior in terms of anti-wear performance and lower friction coefficient.
基金supports provided for this research by the Education Department of Liaoning Province of China (No. 2009T061)Ministry of Education of China (No. [2010] 1561)
文摘K2Ti2O5 and LixK2-xTi2O5 samples with varying K contents （x=0.125, 0.15, 0.3）, targeted on removal of two main environmental pollutants： PM and NOx, were synthesized by the solid state method using TiO2, KNO3 and LiOH-H2O as starting materials and were characterized by X-ray diffractometry, scanning electron microscopy, and BET. The catalytic activity of titanate catalysts on PM oxidation was evaluated using the temperature programmed oxidation （TPO） method. The test results showed that the perovskite structure of K2Ti205 was still retained after doping a small amount of Li, and the catalytic performance of LixK2-xTi2O5 had been improved significantly compared with that of K2Ti2O5. Li0.15K1.85Ti205 catalyst had the highest catalytic activity with an ignition temperature of 210℃ and a peak temperature of 290℃. The catalytic activity of both K2Ti2O5 and LixK2-xTi2O5 under intimate contact was higher than that under loose contact. When the exhaust gas flow rate was around 100 mL/min, the catalyst samples showed a highest activity. The Li doped K2Ti2O5 could be an excellent candidate for PM oxidation due to its high oxidation activity, water stability, resistance to sulfur poisoning and economical advantages.
