为研究黑色页岩遇水膨胀特性,开展不同浸水时间黑色页岩X衍射(XRD)、扫描电镜(SEM)、氮吸附孔径分布等微观试验,得到不同浸水时间条件下黑色页岩矿物成分、微观形貌、崩解特征、晶层间距及晶层膨胀力等膨胀特征微观变化规律。研究结果表...为研究黑色页岩遇水膨胀特性,开展不同浸水时间黑色页岩X衍射(XRD)、扫描电镜(SEM)、氮吸附孔径分布等微观试验,得到不同浸水时间条件下黑色页岩矿物成分、微观形貌、崩解特征、晶层间距及晶层膨胀力等膨胀特征微观变化规律。研究结果表明:黑色页岩遇水后,黏土化趋势显著,矿物组成中产生伊/蒙混层矿物;微观结构由较致密的片层状结构逐渐向不规则的团絮状结构过渡,并出现微观崩解现象;内部孔隙的孔径减小,微孔隙比例增加,出现黏土矿物的絮凝充填产生的0.3~2.0μm的微孔隙;针对白云母、伊利石及伊/蒙混层、绿泥石3种典型片状结构矿物系列的001晶面层间距、晶层间膨胀力进行计算得到,白云母系列矿物晶层间距增长最大,晶层间膨胀力增长124.4%,达92 k Pa;绿泥石系列矿物晶层间距增长次之,晶层间膨胀力增长111.8%,达72 k Pa;伊利石及伊/蒙混层系列矿物晶层间距增长最小,膨胀力增长96.4%,为55 k Pa。由此可见,晶层间膨胀作用力的增大会导致黑色页岩遇水容易产生崩解、软化。展开更多
Four different types of adsorbents, SBA-15, MCM-41, NaY and SiO2, were used to study the dynamic adsorption/desorption of toluene. To further investigate the influence of pore structure on its adsorption performance, ...Four different types of adsorbents, SBA-15, MCM-41, NaY and SiO2, were used to study the dynamic adsorption/desorption of toluene. To further investigate the influence of pore structure on its adsorption performance, two SBA-15 samples with different microspores were also selected. It is shown that microporous material NaY has the largest adsorption capacity of 0.2873 mL/g, and the amorphous SiO2 exhibits the least capacity of 0.1003 mL/g. MCM-41 also shows a lower break through capacity in spite of the relatively small pore diameter, because it can not provide the necessary small geometric confinement for the tiny adsorbates. However, the mesoporous SBA-15 silica with certain micropore volume shows relatively higher adsorption capacity than that of MCM-41 silica. The presence of micropores directly leads to an increase in the dynamic adsorption capacity of toluene. Although NaY has the highest adsorption capacity for toluene, its complete desorption temperature for toluene is high (〉 350°C), which limits its wide application. On the contrary, mesoporous silica materials exhibits a good desorption performance for volatile organic compounds at lower temperatures. Among these materials mesoporous SBA-15 samples, with a larger amount micropores and a lower desorption temperature, are a potentially interesting adsorbent for the removal of volatile organic compounds. This behavior should been related with the best synergetic effect of mesopores and micropores.展开更多
Fe-rich intermetallics, especially β-Fe phase, usually forming in the microstructure of cast aluminum alloys, are very detrimental to mechanical properties. In the present work, the effects of Fe content on phase tra...Fe-rich intermetallics, especially β-Fe phase, usually forming in the microstructure of cast aluminum alloys, are very detrimental to mechanical properties. In the present work, the effects of Fe content on phase transformation and microstructures were analyzed using a 3D X-ray microscope. Based on the highresolution 3D X-ray computed tomography, the 3D characteristics of Fe-rich intermetallics and micropores in the gravity-cast Al-6 Si alloys with different Fe contents were investigated. In addition, the effect of intermetallics on the microporosity was discussed. The results show that with increasing the Fe content from 0.10 wt.% to 0.60 wt.%, the volume fraction of Fe-rich intermetallics and the volume of the largest size Fe-rich intermetallic increased, and the 3D morphology of intermetallics changed from fine flake to network aggregation. As the Fe contents increased, the shrinkage pores were characterized, which were rather complex due to the micropores promoted by the intermetallics interactions.展开更多
Micropores of shale are significant to the gas content and production potential of shale, which has been verified in the research of marine shale gas; while, few studies have been conducted on lacustrine shales. This ...Micropores of shale are significant to the gas content and production potential of shale, which has been verified in the research of marine shale gas; while, few studies have been conducted on lacustrine shales. This study collected 42 samples from three wells in the Late Cretaceous Qingshankou Formation of the southern Songliao Basin, NE China, and investigated these samples by the focused ion beam-scanning electron microscope(FIB–SEM) and nitrogen adsorption analysis techniques. Four types of micropores were identified in the samples, i.e., intergranular pore, intracellular pore, organic matter pore and microfracture. The pore structure type is characterized by open slit pores and "ink type" pores which are mainly 1.5–5 nm in diameter with mesopores as the main pores. The mesopores account for 74.01% of the pore volume and 54.68% of the pore surface area. Compared with the lacustrine shales from the Triassic Yanchang Formation in the Ordos Basin and Xujiahe Formation in the Sichuan Basin, the intergranular clay mineral interlayer pores are considered to be the main reservoir space for shale gas storage in the study area, followed by intraparticle pores, organic matter pores and microfractures. Maturity and micropore are the key controlling factors which affect the shale gas content of the Qingshankou Formation in southern Songliao Basin.展开更多
CO_(2) capture is one of the key technologies for dealing with the global warming and implementing lowcarbon development strategy.The emergence of ionic metal-organic frameworks(I-MOFs)has diversified the field of por...CO_(2) capture is one of the key technologies for dealing with the global warming and implementing lowcarbon development strategy.The emergence of ionic metal-organic frameworks(I-MOFs)has diversified the field of porous materials,which have been extensively applied for gas adsorption and separation.In this work,amino-functionalized imidazolium ionic liquid as organic monodentate ligand was used for one step synthesis microporous Cu based I-MOFs.Precise tuning of the adsorption properties was obtained by incorporating aromatic anions,such as phenoxy,benzene carboxyl,and benzene sulfonic acid group into the I-MOFs via a facile ion exchange method.The new I-MOFs showed high thermal stability and high capacity of 5.4 mmol·g^(-1) under atmospheric conditions for selective adsorption of CO_(2).The active sites of microporous Cu-MOF are the ion basic center and unsaturated metal,and electrostatic attraction and hydroxyl bonding between CO_(2) and modified functional sulfonic groups are responsible for the adsorption.This work provides a feasible strategy for the design of I-MOF for functional gas capture.展开更多
The bedrock weathered crust in front of the Altun Mountains in the Qaidam Basin,western China,is different from others because this is a salt-lake basin,where saline water fluid infiltrates and is deposited in the ove...The bedrock weathered crust in front of the Altun Mountains in the Qaidam Basin,western China,is different from others because this is a salt-lake basin,where saline water fluid infiltrates and is deposited in the overlying strata.A large amount of gypsum infills the bedrock weathered crust,and this has changed the pore structure.Using core observation,polarized light microscopy,electron probe,physical property analysis and field emission scanning electron microscopy experiments,the characteristics of the weathered bedrock have been studied.There are cracks and a small number of dissolved pores in the interior of the weathered crust.Matrix micropores are widely developed,especially the various matrix cracks formed by tectonics and weathering,as well as the stress characteristics of small dissolved pores,and physical properties such as porosity and permeability.This‘dual structure’developed in the bedrock is important for guiding the exploration of the lake basin bedrock for natural gas.展开更多
Energy conversion technologies like fuel cells and metal-air batteries require oxygen reduction reaction(ORR)electrocatalysts with low cost and high catalytic activity.Herein,N-doped carbon spheres(N-CS)with rich micr...Energy conversion technologies like fuel cells and metal-air batteries require oxygen reduction reaction(ORR)electrocatalysts with low cost and high catalytic activity.Herein,N-doped carbon spheres(N-CS)with rich micropore structure have been synthesized by a facile two-step method,which includes the polymerization of pyrrole and formaldehyde and followed by a facile pyrolysis process.During the preparation,zinc chloride(ZnCl2)was utilized as a catalyst to promote polymerization and provide a hypersaline environment.In addition,the morphology,defect content and activity area of the resultant N-CS catalysts could be regulated by controlling the content of ZnCl2.The optimum N-CS-1 catalyst demonstrated much better catalytic activity and durability towards ORR in alkaline conditions than commercial 20 wt%Pt/C catalysts,of which the half-wave potential reached 0.844 V vs.RHE.When applied in the Zn-air batteries as cathode catalysts,N-CS-1 showed a maximum power density of 175 mW cm^(-2) and long-term discharging stability of over 150 h at 10 mA cm^(-2),which outperformed 20 wt%Pt/C.The excellent performance could be due to its ultrahigh specific surface area of 1757 m2 g1 and rich micropore channels structure.Meanwhile,this work provides an efficient method to synthesize an ultrahigh surface porous carbon material,especially for catalyst application.展开更多
Sludge biochar,a carbonized product of raw sludge,contains porous architectures that can act as epicenters for adsorbing external molecules through physical or chemical bonding.Sludge biochar also immobilizes innate m...Sludge biochar,a carbonized product of raw sludge,contains porous architectures that can act as epicenters for adsorbing external molecules through physical or chemical bonding.Sludge biochar also immobilizes innate micropollutants,which is advantageous over conventional sludge disposal methods.To date,numerous strategies have been discovered to improve sludge biochar morphology,but the influential factors,pore tuning mechanisms,and process feasibility remain imprecise.This knowledge gap limits our ability to design a robust sludge-based biochar.Herein,we present state-of-the-art sludge biochar synthesis methods with insight into structural and chemical transformation mechanisms.Roadblocks and novel concepts for improving sludge biochar porous architecture are highlighted.For the first time,sludge biochar properties,adsorption performances,and techno-economic perspectives were compared with commercial activated carbon(AC)to reveal the precise challenges in sludge biochar application.More importantly,sludge biochar role in carbon sequestration is detailed to demonstrate the environmental significance of this technology.Eventually,the review concludes with an overview of prospects and an outlook for developing sludge biochar-based research.展开更多
文摘为研究黑色页岩遇水膨胀特性,开展不同浸水时间黑色页岩X衍射(XRD)、扫描电镜(SEM)、氮吸附孔径分布等微观试验,得到不同浸水时间条件下黑色页岩矿物成分、微观形貌、崩解特征、晶层间距及晶层膨胀力等膨胀特征微观变化规律。研究结果表明:黑色页岩遇水后,黏土化趋势显著,矿物组成中产生伊/蒙混层矿物;微观结构由较致密的片层状结构逐渐向不规则的团絮状结构过渡,并出现微观崩解现象;内部孔隙的孔径减小,微孔隙比例增加,出现黏土矿物的絮凝充填产生的0.3~2.0μm的微孔隙;针对白云母、伊利石及伊/蒙混层、绿泥石3种典型片状结构矿物系列的001晶面层间距、晶层间膨胀力进行计算得到,白云母系列矿物晶层间距增长最大,晶层间膨胀力增长124.4%,达92 k Pa;绿泥石系列矿物晶层间距增长次之,晶层间膨胀力增长111.8%,达72 k Pa;伊利石及伊/蒙混层系列矿物晶层间距增长最小,膨胀力增长96.4%,为55 k Pa。由此可见,晶层间膨胀作用力的增大会导致黑色页岩遇水容易产生崩解、软化。
基金supported by the National Nature Science Foundation of China (No. 20807010)the Program for New Century Excellent Talents in University (No. NCET-09-0256)+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education (No. 200801411111)the National High Technology Research and Development Program (863) of China (No. 2009AA062604)
文摘Four different types of adsorbents, SBA-15, MCM-41, NaY and SiO2, were used to study the dynamic adsorption/desorption of toluene. To further investigate the influence of pore structure on its adsorption performance, two SBA-15 samples with different microspores were also selected. It is shown that microporous material NaY has the largest adsorption capacity of 0.2873 mL/g, and the amorphous SiO2 exhibits the least capacity of 0.1003 mL/g. MCM-41 also shows a lower break through capacity in spite of the relatively small pore diameter, because it can not provide the necessary small geometric confinement for the tiny adsorbates. However, the mesoporous SBA-15 silica with certain micropore volume shows relatively higher adsorption capacity than that of MCM-41 silica. The presence of micropores directly leads to an increase in the dynamic adsorption capacity of toluene. Although NaY has the highest adsorption capacity for toluene, its complete desorption temperature for toluene is high (〉 350°C), which limits its wide application. On the contrary, mesoporous silica materials exhibits a good desorption performance for volatile organic compounds at lower temperatures. Among these materials mesoporous SBA-15 samples, with a larger amount micropores and a lower desorption temperature, are a potentially interesting adsorbent for the removal of volatile organic compounds. This behavior should been related with the best synergetic effect of mesopores and micropores.
基金supported by the Industry Base Enhanced Project(TC160A310-10-01)Guangdong Sci&Tech Project(2013A090100002)Guangzhou Sci&Tech Project(2014Y2-00214)
文摘Fe-rich intermetallics, especially β-Fe phase, usually forming in the microstructure of cast aluminum alloys, are very detrimental to mechanical properties. In the present work, the effects of Fe content on phase transformation and microstructures were analyzed using a 3D X-ray microscope. Based on the highresolution 3D X-ray computed tomography, the 3D characteristics of Fe-rich intermetallics and micropores in the gravity-cast Al-6 Si alloys with different Fe contents were investigated. In addition, the effect of intermetallics on the microporosity was discussed. The results show that with increasing the Fe content from 0.10 wt.% to 0.60 wt.%, the volume fraction of Fe-rich intermetallics and the volume of the largest size Fe-rich intermetallic increased, and the 3D morphology of intermetallics changed from fine flake to network aggregation. As the Fe contents increased, the shrinkage pores were characterized, which were rather complex due to the micropores promoted by the intermetallics interactions.
基金financially supported by the National Natural Science Foundation of China (grant No. 41702171)a National Science and Technology Major Project (grant No. 2016ZX05034002)
文摘Micropores of shale are significant to the gas content and production potential of shale, which has been verified in the research of marine shale gas; while, few studies have been conducted on lacustrine shales. This study collected 42 samples from three wells in the Late Cretaceous Qingshankou Formation of the southern Songliao Basin, NE China, and investigated these samples by the focused ion beam-scanning electron microscope(FIB–SEM) and nitrogen adsorption analysis techniques. Four types of micropores were identified in the samples, i.e., intergranular pore, intracellular pore, organic matter pore and microfracture. The pore structure type is characterized by open slit pores and "ink type" pores which are mainly 1.5–5 nm in diameter with mesopores as the main pores. The mesopores account for 74.01% of the pore volume and 54.68% of the pore surface area. Compared with the lacustrine shales from the Triassic Yanchang Formation in the Ordos Basin and Xujiahe Formation in the Sichuan Basin, the intergranular clay mineral interlayer pores are considered to be the main reservoir space for shale gas storage in the study area, followed by intraparticle pores, organic matter pores and microfractures. Maturity and micropore are the key controlling factors which affect the shale gas content of the Qingshankou Formation in southern Songliao Basin.
基金supported by the National Natural Science Foundation of China(Grant No.22272125)Knowledge Innovation Program of Wuhan-Basic Research(Grant No.2022020801010354)+1 种基金Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(Grant No.2022SX-TD015)Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(Grant No.YLU-DNL Fund 2021021)。
文摘CO_(2) capture is one of the key technologies for dealing with the global warming and implementing lowcarbon development strategy.The emergence of ionic metal-organic frameworks(I-MOFs)has diversified the field of porous materials,which have been extensively applied for gas adsorption and separation.In this work,amino-functionalized imidazolium ionic liquid as organic monodentate ligand was used for one step synthesis microporous Cu based I-MOFs.Precise tuning of the adsorption properties was obtained by incorporating aromatic anions,such as phenoxy,benzene carboxyl,and benzene sulfonic acid group into the I-MOFs via a facile ion exchange method.The new I-MOFs showed high thermal stability and high capacity of 5.4 mmol·g^(-1) under atmospheric conditions for selective adsorption of CO_(2).The active sites of microporous Cu-MOF are the ion basic center and unsaturated metal,and electrostatic attraction and hydroxyl bonding between CO_(2) and modified functional sulfonic groups are responsible for the adsorption.This work provides a feasible strategy for the design of I-MOF for functional gas capture.
基金the National Major Project of Science and Technology in developing great oil&gas field and coal bed gas(Grant No.2016ZX05007-006)the Study on water-cut control and production stabilization in the old gasfields and efficient development in new gasfields in Qaidam Basin(Grant No.2016E-0106GF)。
文摘The bedrock weathered crust in front of the Altun Mountains in the Qaidam Basin,western China,is different from others because this is a salt-lake basin,where saline water fluid infiltrates and is deposited in the overlying strata.A large amount of gypsum infills the bedrock weathered crust,and this has changed the pore structure.Using core observation,polarized light microscopy,electron probe,physical property analysis and field emission scanning electron microscopy experiments,the characteristics of the weathered bedrock have been studied.There are cracks and a small number of dissolved pores in the interior of the weathered crust.Matrix micropores are widely developed,especially the various matrix cracks formed by tectonics and weathering,as well as the stress characteristics of small dissolved pores,and physical properties such as porosity and permeability.This‘dual structure’developed in the bedrock is important for guiding the exploration of the lake basin bedrock for natural gas.
基金financially supported by the National Key R&D Program of China (No. 2018YFB0104000 and No. 2019YFA0210300)National Nature Science Foundation of China (No.21571189 and No.21671200)+3 种基金Natural Science Foundation of Jiangsu Province (BK20200991)Hunan Provincial Science and Technology Plan Project of China (No. 2019GK2033, No. 2017TP1001, CPS2019K06 and No. 2018RS3009)Postdoctoral International Exchange Program Funding of China (No. [2018]115)China Postdoctoral Science Foundation (2019M652802)
文摘Energy conversion technologies like fuel cells and metal-air batteries require oxygen reduction reaction(ORR)electrocatalysts with low cost and high catalytic activity.Herein,N-doped carbon spheres(N-CS)with rich micropore structure have been synthesized by a facile two-step method,which includes the polymerization of pyrrole and formaldehyde and followed by a facile pyrolysis process.During the preparation,zinc chloride(ZnCl2)was utilized as a catalyst to promote polymerization and provide a hypersaline environment.In addition,the morphology,defect content and activity area of the resultant N-CS catalysts could be regulated by controlling the content of ZnCl2.The optimum N-CS-1 catalyst demonstrated much better catalytic activity and durability towards ORR in alkaline conditions than commercial 20 wt%Pt/C catalysts,of which the half-wave potential reached 0.844 V vs.RHE.When applied in the Zn-air batteries as cathode catalysts,N-CS-1 showed a maximum power density of 175 mW cm^(-2) and long-term discharging stability of over 150 h at 10 mA cm^(-2),which outperformed 20 wt%Pt/C.The excellent performance could be due to its ultrahigh specific surface area of 1757 m2 g1 and rich micropore channels structure.Meanwhile,this work provides an efficient method to synthesize an ultrahigh surface porous carbon material,especially for catalyst application.
基金The United Envirotech Water Treatment(Dafeng)Co.,Ltd(project no.04150700723).
文摘Sludge biochar,a carbonized product of raw sludge,contains porous architectures that can act as epicenters for adsorbing external molecules through physical or chemical bonding.Sludge biochar also immobilizes innate micropollutants,which is advantageous over conventional sludge disposal methods.To date,numerous strategies have been discovered to improve sludge biochar morphology,but the influential factors,pore tuning mechanisms,and process feasibility remain imprecise.This knowledge gap limits our ability to design a robust sludge-based biochar.Herein,we present state-of-the-art sludge biochar synthesis methods with insight into structural and chemical transformation mechanisms.Roadblocks and novel concepts for improving sludge biochar porous architecture are highlighted.For the first time,sludge biochar properties,adsorption performances,and techno-economic perspectives were compared with commercial activated carbon(AC)to reveal the precise challenges in sludge biochar application.More importantly,sludge biochar role in carbon sequestration is detailed to demonstrate the environmental significance of this technology.Eventually,the review concludes with an overview of prospects and an outlook for developing sludge biochar-based research.