The formation and growth of Li-dendrites caused by inhomogeneous Li deposition severely hinder the commercial applications of Li metal batteries due to the consequence of short-circuiting.Herein,we propose a Janus bil...The formation and growth of Li-dendrites caused by inhomogeneous Li deposition severely hinder the commercial applications of Li metal batteries due to the consequence of short-circuiting.Herein,we propose a Janus bilayer composed of black phosphorus(BP)and graphene oxide(GO)as an artificial interface with chemical/mechanical stability and well-regulated Li-ion flux distribution for Li metal anode protection.Owing to the synergy between the fast Li-ion transport of BP in the inner layer and the high mechanical and chemical stability of GO in the outer layer,the GO/BP with good electrolyte wettability acts as a Li-ion regulator that can induce homogeneous growth of Li to suppress the Li dendrites growth.Accordingly,long-term stability(500 h at 1 mA cm^(-2))with a low overpotential of 30 mV is achieved in the symmetric cell with GO/BP-Li anode.Furthermore,the Li–S cell with GO/BP-Li exhibits enhanced cycling performance with a high capacity retention rate of 76.2%over 500 cycles at 1 C.展开更多
Hydrogenation of benzaldehyde is a typical consecutive reaction, since the intermediate benzyl alcohol is apt to be further hydrogenated. Here we demonstrate that the selectivity of benzyl alcohol can be tuned via fun...Hydrogenation of benzaldehyde is a typical consecutive reaction, since the intermediate benzyl alcohol is apt to be further hydrogenated. Here we demonstrate that the selectivity of benzyl alcohol can be tuned via functionalization of carbon nanotubes （CNTs）, which are used as the support of Pd. With the original CNTs, the selectivity of benzyl alcohol is 88% at a 100% conversion of benzaldehyde. With introduction of oxygen-containing groups onto CNTs, it drops to 27%. In contrast, doping CNTs with N atoms, the selectivity reaches 96% under the same reaction conditions. The kinetic study shows that hydrogenation of benzyl alcohol is significantly suppressed, which can be attributed to weakened adsorption of benzyl alcohol. This is most likely related to the modified electronic structure of Pd species via interaction with functionalized CNTs, as shown by XPS characterization.展开更多
3D seismic data recently acquired from the Ordos Basin shows three sets of regularly distributed fault systems,which overrides previous understanding that no faults were developed in this basin.Seismic interpretation ...3D seismic data recently acquired from the Ordos Basin shows three sets of regularly distributed fault systems,which overrides previous understanding that no faults were developed in this basin.Seismic interpretation suggests that the faults in the southwestern Ordos Basin have three basic characteristics,namely extreme micro-scale,distinct vertical stratification,and regularity of planar distribution.These NS-,NW-,and NE-trending fault systems developed in the Meso-Neoproterozoic e Lower Ordovician strata.Of these,the NS-trending fault system mainly consists of consequent and antithetic faults which show clear syndepositional deformation.The fault systems in the Carboniferous e Middle-Lower Triassic strata are not clear on seismic reflection profiles.The NW-and NE-trending fault systems are developed in the Upper Triassic e Middle Jurassic strata.Of these,the NW-trending fault system appears as a negative flower structure in sectional view and in an en echelon pattern in plan-view;they show transtensional deformation.A NE-trending fault system that developed in the Lower Cretaceous e Cenozoic strata shows a Y-shaped structural style and tension-shear properties.A comprehensive analysis of the regional stress fields at different geologic times is essential to determine the development,distribution direction,and intensity of the activity of fault systems in the Ordos Basin.Current exploration suggests three aspects in which the faults within the Ordos Basin are crucial to oil and gas accumulation.Firstly,these faults serve as vertical barriers that cause the formation of two sets of relatively independent petroleum systems in the Paleozoic and Mesozoic strata respectively;this is the basis for the‘upper oil and lower gas’distribution pattern.Secondly,the vertical communication of these faults is favorable for oil and gas migration,thus contributing to the typical characteristics of multiple oil and gas fields within the basin,i.e.oil and gas reservoirs with multiple superimposed strata.Finally,these faults and their associated fractures improve the permeability of Mesozoic tight reservoirs,providing favorable conditions for oil enrichment in areas around the fault systems.展开更多
Commercial production of vinyl chloride from acetylene relies on the use of HgCla as the catalyst, which has caused severe environmental problem and threats to human health because of its toxicity. Therefore, it is vi...Commercial production of vinyl chloride from acetylene relies on the use of HgCla as the catalyst, which has caused severe environmental problem and threats to human health because of its toxicity. Therefore, it is vital to explore alternative catalysts without mercury. We report here that N-doped carbon can catalyze directly transformation of acetylene to vinyl chloride. Particularly, N-doped high surface area mesoporous carbon exhibits a rather high activity with the acetylene conversion reaching 77% and vinyl chloride selectivity above 98% at a space velocity of 1.0 mL.min-l.g-1 and 200 ~C. It delivers a stable performa℃nce within a test period of 100h and no obvious deactivation is observed, demonstrating potentials to substitute the notoriously toxic mercuric chloride catalyst.展开更多
Amorphous alloys,also known as metallic glasses,are solid metallic materials having long-range disordered atomic structures.Compared to crystalline alloys,amorphous alloys not only have metallic characters,but also po...Amorphous alloys,also known as metallic glasses,are solid metallic materials having long-range disordered atomic structures.Compared to crystalline alloys,amorphous alloys not only have metallic characters,but also possess several distinct properties associated to the amorphous structure,such as isotropy,composition flexibility,unsaturated surface,etc.As a result,amorphous alloys offer a class of highly promising materials for catalyzing electrochemical reactions.In this minireview,the preparation,characterization and electrocatalytic performances of a variety of metallic amorphous alloy materials are summarized.The influences of the amorphous alloy structure on different electrochemical reactions are discussed.Finally,a summary on the advantages and challenges of amorphous alloys in electrocatalysis is provided,along with some perspectives about the future research directions.展开更多
Exploring highly efficient Pt-free catalysts for hydrogen evolution reaction(HER)is of great importance for hydrogen(H2)production.Herein,a novel HER electrocatalyst having abundant ultra-small(2–3 nm)Ru electronical...Exploring highly efficient Pt-free catalysts for hydrogen evolution reaction(HER)is of great importance for hydrogen(H2)production.Herein,a novel HER electrocatalyst having abundant ultra-small(2–3 nm)Ru electronically confined by a B,N codoped polar carbon surface(Ru/(B-N)-PC)was constructed.The Ru/(B-N)-PC catalyst exhibits a low overpotential of 15 mV at the current density of 10 mA·cm^(−2),a low Tafel slope of 22.6 mV·dec^(−1),superior durability,which outperforms the benchmark Pt/C catalyst.Both experimental characterizations and theory calculations suggest that an electron communication established between B,N co-doped carbon surface and ultra-small Ru nanoparticles with electrons transferred from N atoms to Ru and backtransferred from Ru to B atoms,which exerts a moderate electronic modification of Ru.This,in turn,affords a modest H adsorption energy and a lower H2O dissociation barrier,leading to the high-performance hydrogen evolution reaction.The work provides meaningful insight into the size control and electronic modulation of Ru catalyst for intrinsic HER activity improvement.展开更多
Ultrathin two-dimensional(2 D)porous nanosheets are one of the most promising nanomaterials in various applications,whereas their synthesis is still challenging.Herein,ultrathin 2 D amorphous TiO_(2)(a-TiO_(2))porous ...Ultrathin two-dimensional(2 D)porous nanosheets are one of the most promising nanomaterials in various applications,whereas their synthesis is still challenging.Herein,ultrathin 2 D amorphous TiO_(2)(a-TiO_(2))porous nanosheet aerogel is synthesized via a surfactant-free assembly process followed by low-temperature calcination.The co-existing O-O and-OH groups on the surface of TiO_(2)precursor break the 3 D spherical symmetry,and the hydrogen bonding among the TiO_(2)precursors is proposed as the main driving force guiding the 2 D assembly.The surfactant-free assembly endows the ultrathin a-TiO_(2)porous nanosheet with improved ionic and electronic conductivity.The porous structure provides high surface area and easy electrolyte penetration,accelerating the Li ion diffusion rate of the a-TiO_(2)porous nanosheet.Attributing to the above advantages,the obtained a-TiO_(2)porous nanosheets are one of the best anode materials for lithium-ion batteries,which is proved by the enhanced electrochemical performance.展开更多
基金financially supported by the National Natural Science Foundation of China(21771154)the Shenzhen Fundamental Research Programs(JCYJ20190809161013453)+1 种基金the Fundamental Research Funds for the Central Universities(20720220031)the 111 Project(B16029)。
文摘The formation and growth of Li-dendrites caused by inhomogeneous Li deposition severely hinder the commercial applications of Li metal batteries due to the consequence of short-circuiting.Herein,we propose a Janus bilayer composed of black phosphorus(BP)and graphene oxide(GO)as an artificial interface with chemical/mechanical stability and well-regulated Li-ion flux distribution for Li metal anode protection.Owing to the synergy between the fast Li-ion transport of BP in the inner layer and the high mechanical and chemical stability of GO in the outer layer,the GO/BP with good electrolyte wettability acts as a Li-ion regulator that can induce homogeneous growth of Li to suppress the Li dendrites growth.Accordingly,long-term stability(500 h at 1 mA cm^(-2))with a low overpotential of 30 mV is achieved in the symmetric cell with GO/BP-Li anode.Furthermore,the Li–S cell with GO/BP-Li exhibits enhanced cycling performance with a high capacity retention rate of 76.2%over 500 cycles at 1 C.
基金supported by the National Science Foundation of China (No. 21006129,11079005 and 21033009)the Ministry of Science and Technology of China (No. 2011CBA00503)
文摘Hydrogenation of benzaldehyde is a typical consecutive reaction, since the intermediate benzyl alcohol is apt to be further hydrogenated. Here we demonstrate that the selectivity of benzyl alcohol can be tuned via functionalization of carbon nanotubes （CNTs）, which are used as the support of Pd. With the original CNTs, the selectivity of benzyl alcohol is 88% at a 100% conversion of benzaldehyde. With introduction of oxygen-containing groups onto CNTs, it drops to 27%. In contrast, doping CNTs with N atoms, the selectivity reaches 96% under the same reaction conditions. The kinetic study shows that hydrogenation of benzyl alcohol is significantly suppressed, which can be attributed to weakened adsorption of benzyl alcohol. This is most likely related to the modified electronic structure of Pd species via interaction with functionalized CNTs, as shown by XPS characterization.
基金project entitled Seismic Identification and Accumulation Control of Strike-Slip Faults in Superimposed Basins inWest-central Part of China initiated by the Bureau of Geophysical Prospecting,CNPC(No.:03-02-2022).
文摘3D seismic data recently acquired from the Ordos Basin shows three sets of regularly distributed fault systems,which overrides previous understanding that no faults were developed in this basin.Seismic interpretation suggests that the faults in the southwestern Ordos Basin have three basic characteristics,namely extreme micro-scale,distinct vertical stratification,and regularity of planar distribution.These NS-,NW-,and NE-trending fault systems developed in the Meso-Neoproterozoic e Lower Ordovician strata.Of these,the NS-trending fault system mainly consists of consequent and antithetic faults which show clear syndepositional deformation.The fault systems in the Carboniferous e Middle-Lower Triassic strata are not clear on seismic reflection profiles.The NW-and NE-trending fault systems are developed in the Upper Triassic e Middle Jurassic strata.Of these,the NW-trending fault system appears as a negative flower structure in sectional view and in an en echelon pattern in plan-view;they show transtensional deformation.A NE-trending fault system that developed in the Lower Cretaceous e Cenozoic strata shows a Y-shaped structural style and tension-shear properties.A comprehensive analysis of the regional stress fields at different geologic times is essential to determine the development,distribution direction,and intensity of the activity of fault systems in the Ordos Basin.Current exploration suggests three aspects in which the faults within the Ordos Basin are crucial to oil and gas accumulation.Firstly,these faults serve as vertical barriers that cause the formation of two sets of relatively independent petroleum systems in the Paleozoic and Mesozoic strata respectively;this is the basis for the‘upper oil and lower gas’distribution pattern.Secondly,the vertical communication of these faults is favorable for oil and gas migration,thus contributing to the typical characteristics of multiple oil and gas fields within the basin,i.e.oil and gas reservoirs with multiple superimposed strata.Finally,these faults and their associated fractures improve the permeability of Mesozoic tight reservoirs,providing favorable conditions for oil enrichment in areas around the fault systems.
基金supported by the Natural Science Foundation of China(No.11079005 and 21033009)the Ministry of Science and Technology of China(2011CBA00503 and 2012CB720302)
文摘Commercial production of vinyl chloride from acetylene relies on the use of HgCla as the catalyst, which has caused severe environmental problem and threats to human health because of its toxicity. Therefore, it is vital to explore alternative catalysts without mercury. We report here that N-doped carbon can catalyze directly transformation of acetylene to vinyl chloride. Particularly, N-doped high surface area mesoporous carbon exhibits a rather high activity with the acetylene conversion reaching 77% and vinyl chloride selectivity above 98% at a space velocity of 1.0 mL.min-l.g-1 and 200 ~C. It delivers a stable performa℃nce within a test period of 100h and no obvious deactivation is observed, demonstrating potentials to substitute the notoriously toxic mercuric chloride catalyst.
基金supported by the Ministry of Education of Singapore under Tier 1 RG115/18 and RG4/20,and Tier 2 T2EP10120-0009.
文摘Amorphous alloys,also known as metallic glasses,are solid metallic materials having long-range disordered atomic structures.Compared to crystalline alloys,amorphous alloys not only have metallic characters,but also possess several distinct properties associated to the amorphous structure,such as isotropy,composition flexibility,unsaturated surface,etc.As a result,amorphous alloys offer a class of highly promising materials for catalyzing electrochemical reactions.In this minireview,the preparation,characterization and electrocatalytic performances of a variety of metallic amorphous alloy materials are summarized.The influences of the amorphous alloy structure on different electrochemical reactions are discussed.Finally,a summary on the advantages and challenges of amorphous alloys in electrocatalysis is provided,along with some perspectives about the future research directions.
基金the National Natural Science Foundation of China(No.22072069)the Research Fund Program of Guangdong Provincial Key Lab of Green Chemical Product Technology(No.GC202101)+3 种基金the Hubei Key Laboratory of Processing and Application of Catalytic materials(No.202121904)the State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter(No.20210012)the JST-ERATO Yamauchi Materials Space-Tectonics Project(No.JPMJER2003)the Researchers Supporting Project(No.RSP-2021/243),King Saud University,Riyadh,Saudi Arabia.
文摘Exploring highly efficient Pt-free catalysts for hydrogen evolution reaction(HER)is of great importance for hydrogen(H2)production.Herein,a novel HER electrocatalyst having abundant ultra-small(2–3 nm)Ru electronically confined by a B,N codoped polar carbon surface(Ru/(B-N)-PC)was constructed.The Ru/(B-N)-PC catalyst exhibits a low overpotential of 15 mV at the current density of 10 mA·cm^(−2),a low Tafel slope of 22.6 mV·dec^(−1),superior durability,which outperforms the benchmark Pt/C catalyst.Both experimental characterizations and theory calculations suggest that an electron communication established between B,N co-doped carbon surface and ultra-small Ru nanoparticles with electrons transferred from N atoms to Ru and backtransferred from Ru to B atoms,which exerts a moderate electronic modification of Ru.This,in turn,affords a modest H adsorption energy and a lower H2O dissociation barrier,leading to the high-performance hydrogen evolution reaction.The work provides meaningful insight into the size control and electronic modulation of Ru catalyst for intrinsic HER activity improvement.
基金financially supported by the National Natural Science Foundation of China(21771154)Shenzhen Fundamental Research Programs(JCYJ20190809161013453)+1 种基金the Fundamental Research Funds for the Central Universities(20720220031)the 111 Project(B16029)。
文摘Ultrathin two-dimensional(2 D)porous nanosheets are one of the most promising nanomaterials in various applications,whereas their synthesis is still challenging.Herein,ultrathin 2 D amorphous TiO_(2)(a-TiO_(2))porous nanosheet aerogel is synthesized via a surfactant-free assembly process followed by low-temperature calcination.The co-existing O-O and-OH groups on the surface of TiO_(2)precursor break the 3 D spherical symmetry,and the hydrogen bonding among the TiO_(2)precursors is proposed as the main driving force guiding the 2 D assembly.The surfactant-free assembly endows the ultrathin a-TiO_(2)porous nanosheet with improved ionic and electronic conductivity.The porous structure provides high surface area and easy electrolyte penetration,accelerating the Li ion diffusion rate of the a-TiO_(2)porous nanosheet.Attributing to the above advantages,the obtained a-TiO_(2)porous nanosheets are one of the best anode materials for lithium-ion batteries,which is proved by the enhanced electrochemical performance.
