在日益增长的能源需求与日益严峻的全球气候变化带来的双重压力下,清洁、高效且经济的能源利用方法显得尤为重要。将化学链概念用于传统化石能源的转化是一种前景广阔的新技术。化学链燃烧利用载氧体间接转化含碳燃料,同时实现二氧化碳...在日益增长的能源需求与日益严峻的全球气候变化带来的双重压力下,清洁、高效且经济的能源利用方法显得尤为重要。将化学链概念用于传统化石能源的转化是一种前景广阔的新技术。化学链燃烧利用载氧体间接转化含碳燃料,同时实现二氧化碳的捕集。俄亥俄州立大学研发了采用铁基载氧体和移动床反应器的化学链技术,可实现天然气、煤、生物质等多种燃料向电力、氢、液体燃料等产品的零排放转化。目前,合成气化学链(syngas chemical looping,SCL)和煤直接化学链(coal direct chemical looping,CDCL)技术两套25 kWth级小试装置已成功运行总计超过850 h,一套250 kWth级的高压SCL装置即将投入示范运行。展开更多
A sequential anode-cathode double-chamber microbial fuel cell （MFC）, in which the effluent of anode chamber was used as a continuous feed for an aerated cathode chamber, was constructed in this experiment to investi...A sequential anode-cathode double-chamber microbial fuel cell （MFC）, in which the effluent of anode chamber was used as a continuous feed for an aerated cathode chamber, was constructed in this experiment to investigate the performance of brewery wastewater treatment in conjugation with electricity generation. Carbon fiber was used as anode and plain carbon felt with biofilm as cathode. When hydraulic retention time （HRT） was 14.7 h, a relatively high chemical oxygen demand （COD） removal efficiency of 91.7%-95.7% was achieved under long-term stable operation. The MFC displayed an open circuit voltage of 0.434 V and a maximum power density of 830 mW/m^3 at an external resistance of 300 0. To estimate the electrochemical performance of the MFC, electrochemical measurements were carried out and showed that polarization resistance of anode was the major limiting factor in the MFC. Since a high COD removal efficiency was achieved, we conclude that the sequential anode-cathode MFC constructed with bio-cathode in this experiment could provide a new approach for brewery wastewater treatment.展开更多
This work focuses on the development of high temperature polymer electrolyte membranes(HT-PEMs)as key materials for HT-PEM fuel cells(HT-PEMFCs).Recognizing the challenges associated with the phosphoric acid(PA) doped...This work focuses on the development of high temperature polymer electrolyte membranes(HT-PEMs)as key materials for HT-PEM fuel cells(HT-PEMFCs).Recognizing the challenges associated with the phosphoric acid(PA) doped polybenzimidazole(PBI) membranes,including the use of carcinogenic monomers and complex synthesis procedures,this study aims to develop more cost-effective,readily synthesized,and high-performance alternatives.A series of superacid-catalyzed polyhydroxyalkylation reactions have been carefully designed between p-terphenyl and aldehydes bearing imidazole moieties,resulting in a new class of HT-PEMs.It is found that the chemical structure of aldehyde-substituted N-heterocycles significantly impacts the polymerization reaction.Specifically,the use of 1-methyl-2-imidazole-formaldehyde and 1 H-imidazole-4-formaldehyde monomers leads to the formation of high-viscosity,rigid,and ether-free polymers,denoted as PTIm-a and PTIm-b.Membranes fabricated from these polymers,due to their pendent imidazole groups,exhibit an exceptional capacity for PA absorption.Notably,PTIm-a,carrying methylimidazole moieties,demonstrates a superior chemical stability by maintaining morphology and structural stability during 350 h of Fenton testing.After being immersed in 75 wt% PA at 40℃,the PTIm-a membrane reaches a PA content of 152%,maintains a good tensile strength of 13.6 MPa,and exhibits a moderate conductivity of 50.2 mS cm^(-1) at 180℃.Under H_(2)/O_(2) operational conditions,a single cell based on the PTIm-a membrane attains a peak power density of 732 mW cm^(-2) at 180℃ without backpressure.Furthermore,the membrane demonstrates stable cycle stability over 173 h within 18 days at a current density of 200 mA cm^(-2),indicating its potential for practical application in HT-PEMFCs.This work highlights innovative strategies for the synthesis of advanced HT-PEMs,offering significant improvements in membrane properties and fuel cell performance,thus expanding the horizons of HT-PEMFC technology.展开更多
The field of supramolecular chemistry is rapidly progressing,transitioning from the creation of thermodynamically stable systems found in local or global minima on the free energy landscape to the development of out-o...The field of supramolecular chemistry is rapidly progressing,transitioning from the creation of thermodynamically stable systems found in local or global minima on the free energy landscape to the development of out-of-equilibrium systems that rely on chemical reactions to establish and maintain their structures.Over the past decade,numerous artificial out-of-equilibrium systems have been devised in various domains of supramolecular chemistry,many of which have been extensively reviewed.However,one area that has received limited attention thus far is the use of out-of-equilibrium processes to regulate host-guest interactions.This minireview aims to address this gap by exploring the construction of out-ofequilibrium systems based on host-guest complexation,which likely employs similar strategies to those employed in analogous noncovalent interactions.The review begins with a summary of these shared strategies.Subsequently,it discusses representative publications that exemplify these strategies and classifies thembased onwhich component is being modulated-host,guest,or competitive molecules.Through this examination,our objective is to shed light on the design of out-of-equilibrium systems relying on host-guest interactions and provide valuable insights into the preparation strategies for various transient materials.展开更多
This numerical study investigates the effects of using a diluted fuel （50% natural gas and 50% N2） in an industrial furnace under several cases of conventional combustion （air with 21% O2 at 300 and 1273 K） and th...This numerical study investigates the effects of using a diluted fuel （50% natural gas and 50% N2） in an industrial furnace under several cases of conventional combustion （air with 21% O2 at 300 and 1273 K） and the highly preheated and diluted air （1273 K with 10% O2 and 90% N2） combustion （HPDAC） conditions using an in-house computer program. It was found that by applying a combined diluted fuel and oxidant instead of their uncombined and/or undiluted states, the best condition is obtained for the establishment of HPDAC＇s main unique features. These features are low mean and maximum gas temperature and high radiation/total heat transfer to gas and tubes; as well as more uniformity of theirs distributions which results in decrease in NOx pollutant formation and increase in furnace efficiency or energy saving. Moreover, a variety of chemical flame shape, the process fluid and tubes walls temperatures profiles, the required regenerator efficiency and finally the concentration and velocity patterns have been also qualitatively/quantitatively studied.展开更多
The physicochemical properties of liquid alternative fuels are important but difficult to measure/predict, especially when complex surrogate fuels are concerned. In the present work, machine learning is used to develo...The physicochemical properties of liquid alternative fuels are important but difficult to measure/predict, especially when complex surrogate fuels are concerned. In the present work, machine learning is used to develop quantitative structure–property relationship models. The fuel chemical structure is represented by molecular descriptors, allowing the linking of important features of the fuel composition and key properties of fuel utilization. Feature selection is employed to select the most relevant features that describe the chemical structure of the fuel and several machine learning algorithms are tested to construct interpretable models. The effectiveness of the methodology is demonstrated through the development of accurate and interpretable predictive models for cetane numbers, with a focus on understanding the link between molecular structure and fuel properties. In this context, matrix-based descriptors and descriptors related to the number of atoms in the molecule are directly linked with the cetane number of hydrocarbons. Furthermore, the results showed that molecular connectivity indices play a role in the cetane number for aromatic molecules. Also, the methodology is extended to predict the cetane number of ester and ether molecules, leveraging the design of alternative fuels towards fully sustainable fuel utilization.展开更多
Self-assembly has been extensively studied in chemistry,physics,biology,and materials engineering and has become an important“bottom-up”approach in creating intriguing structures for different applications.Using dis...Self-assembly has been extensively studied in chemistry,physics,biology,and materials engineering and has become an important“bottom-up”approach in creating intriguing structures for different applications.Using dissipative self-assembly to construct fuel-dependent,energy-consuming,and dynamic nonequilibrium systems is important for developing intelligent life-like materials.Furthermore,dissipative self-assembly has become a research hotspot in materials chemistry,biomedical science,environmental chemistry,and physical chemistry.An in-depth understanding of the process and mechanism provides useful insights to the researchers for devel-oping materials using dissipative self-assembly and also helps guide future innovation in material fabrication.This critical review comprehensively analyzes various chemical fuel input and energy consumption mechanisms,supported by numerous illustrative examples.Versatile transient assemblies,including gels,vesicles,micelles,and nanoparticle aggregates,have been systematically studied in our and other laboratories.The relationship between the molecular structure of precursors and temporal assemblies in dissipative self-assemblies is discussed from the perspective of physical chemistry.Using dissipative self-assembly methods to construct functional assemblies provides important implications for constructing high-energy,nonequilibrium,and intelligent functional materials.展开更多
The intermetallic compounds formation at interface between rare earth elements and clad material were investigated to demonstrate the effects of rare earth elements on fuel-cladding chemical interaction （FCCI） behav...The intermetallic compounds formation at interface between rare earth elements and clad material were investigated to demonstrate the effects of rare earth elements on fuel-cladding chemical interaction （FCCI） behavior. Mischmetal （70Ce-30La） and Nd were prepared as rare earth elements. Diffusion couple testing was performed on the rare earth elements and cladding （9Cr2W steel） near the operation temperature of （sodium-cooled fast reactor） SFR fuel. The performance of a diffusion barrier consisting of Zr and V metallic foil against the rare earth elements was also evaluated. Our results showed that Ce and Nd in the rare earth elements and Fe in the clad material interdiffused and reacted to form intermetallic species according to the parabolic rate law, describing the migration of the rare earth element. The diffusion of Fe limited the reaction progress such that the entire process was governed by the cubic rate law. Rare earth materials could be used as a surrogate for high burnup metallic fuels, and the performance of the barrier material was demonstrated to be effective.展开更多
Photocatalytic splitting of water was carried out in a two-phase system. Nanocrystalline titanium dioxide was used as photocatalyst and potassium hexacyanoferrate(III)/(II) as electron transporter. Generated hydrogen ...Photocatalytic splitting of water was carried out in a two-phase system. Nanocrystalline titanium dioxide was used as photocatalyst and potassium hexacyanoferrate(III)/(II) as electron transporter. Generated hydrogen was chemically stored by use of a 1,4-benzoquinone/1,4-hydroquinone system, which was used as a recyclable fuel in a commercialised direct methanol fuel cell (DMFC). The electrical output of the cell was about half compared to methanol. The conversion process for water splitting and recombination in a fuel cell was monitored by UV-Vis spectroscopy and compared to a simulated spectrum. Products of side reactions, which lead to a decrease of the overall efficiency, were identified based on UV-Vis investigations. A proof of principle for the use of quinoide systems as a recyclable hydrogen storage system in a photocatalytic water splitting and fuel cell cyclic process was given.展开更多
基金sponsored financially by the National Natural Science Foundation of China (No.91545103 and 21273071)the Science and Technology Commission of Shanghai Municipality (13JC1401902)
文摘在日益增长的能源需求与日益严峻的全球气候变化带来的双重压力下,清洁、高效且经济的能源利用方法显得尤为重要。将化学链概念用于传统化石能源的转化是一种前景广阔的新技术。化学链燃烧利用载氧体间接转化含碳燃料,同时实现二氧化碳的捕集。俄亥俄州立大学研发了采用铁基载氧体和移动床反应器的化学链技术,可实现天然气、煤、生物质等多种燃料向电力、氢、液体燃料等产品的零排放转化。目前,合成气化学链(syngas chemical looping,SCL)和煤直接化学链(coal direct chemical looping,CDCL)技术两套25 kWth级小试装置已成功运行总计超过850 h,一套250 kWth级的高压SCL装置即将投入示范运行。
基金Project supported by the Heilongjiang Science and Technology Key Projects (No. GC07A305)the Fund of Harbin Engineering University (No. HEUFT08008)the Daqing Science and Technology Key Projects (No. SGG2008-029), Heilongjiang, China
文摘A sequential anode-cathode double-chamber microbial fuel cell （MFC）, in which the effluent of anode chamber was used as a continuous feed for an aerated cathode chamber, was constructed in this experiment to investigate the performance of brewery wastewater treatment in conjugation with electricity generation. Carbon fiber was used as anode and plain carbon felt with biofilm as cathode. When hydraulic retention time （HRT） was 14.7 h, a relatively high chemical oxygen demand （COD） removal efficiency of 91.7%-95.7% was achieved under long-term stable operation. The MFC displayed an open circuit voltage of 0.434 V and a maximum power density of 830 mW/m^3 at an external resistance of 300 0. To estimate the electrochemical performance of the MFC, electrochemical measurements were carried out and showed that polarization resistance of anode was the major limiting factor in the MFC. Since a high COD removal efficiency was achieved, we conclude that the sequential anode-cathode MFC constructed with bio-cathode in this experiment could provide a new approach for brewery wastewater treatment.
基金Natural Science Foundation of China (51603031)Liaoning Provincial Natural Science Foundation of China (2020-MS-087)China Scholarship Council(202306080157)。
文摘This work focuses on the development of high temperature polymer electrolyte membranes(HT-PEMs)as key materials for HT-PEM fuel cells(HT-PEMFCs).Recognizing the challenges associated with the phosphoric acid(PA) doped polybenzimidazole(PBI) membranes,including the use of carcinogenic monomers and complex synthesis procedures,this study aims to develop more cost-effective,readily synthesized,and high-performance alternatives.A series of superacid-catalyzed polyhydroxyalkylation reactions have been carefully designed between p-terphenyl and aldehydes bearing imidazole moieties,resulting in a new class of HT-PEMs.It is found that the chemical structure of aldehyde-substituted N-heterocycles significantly impacts the polymerization reaction.Specifically,the use of 1-methyl-2-imidazole-formaldehyde and 1 H-imidazole-4-formaldehyde monomers leads to the formation of high-viscosity,rigid,and ether-free polymers,denoted as PTIm-a and PTIm-b.Membranes fabricated from these polymers,due to their pendent imidazole groups,exhibit an exceptional capacity for PA absorption.Notably,PTIm-a,carrying methylimidazole moieties,demonstrates a superior chemical stability by maintaining morphology and structural stability during 350 h of Fenton testing.After being immersed in 75 wt% PA at 40℃,the PTIm-a membrane reaches a PA content of 152%,maintains a good tensile strength of 13.6 MPa,and exhibits a moderate conductivity of 50.2 mS cm^(-1) at 180℃.Under H_(2)/O_(2) operational conditions,a single cell based on the PTIm-a membrane attains a peak power density of 732 mW cm^(-2) at 180℃ without backpressure.Furthermore,the membrane demonstrates stable cycle stability over 173 h within 18 days at a current density of 200 mA cm^(-2),indicating its potential for practical application in HT-PEMFCs.This work highlights innovative strategies for the synthesis of advanced HT-PEMs,offering significant improvements in membrane properties and fuel cell performance,thus expanding the horizons of HT-PEMFC technology.
基金the financial support of the Chinese Scholarship Council(CSC)the Science and Technology Department of Shandong Province(grant no.ZR202211300055).
文摘The field of supramolecular chemistry is rapidly progressing,transitioning from the creation of thermodynamically stable systems found in local or global minima on the free energy landscape to the development of out-of-equilibrium systems that rely on chemical reactions to establish and maintain their structures.Over the past decade,numerous artificial out-of-equilibrium systems have been devised in various domains of supramolecular chemistry,many of which have been extensively reviewed.However,one area that has received limited attention thus far is the use of out-of-equilibrium processes to regulate host-guest interactions.This minireview aims to address this gap by exploring the construction of out-ofequilibrium systems based on host-guest complexation,which likely employs similar strategies to those employed in analogous noncovalent interactions.The review begins with a summary of these shared strategies.Subsequently,it discusses representative publications that exemplify these strategies and classifies thembased onwhich component is being modulated-host,guest,or competitive molecules.Through this examination,our objective is to shed light on the design of out-of-equilibrium systems relying on host-guest interactions and provide valuable insights into the preparation strategies for various transient materials.
基金Supported by the National Iranian Oil Company (NIOC)
文摘This numerical study investigates the effects of using a diluted fuel （50% natural gas and 50% N2） in an industrial furnace under several cases of conventional combustion （air with 21% O2 at 300 and 1273 K） and the highly preheated and diluted air （1273 K with 10% O2 and 90% N2） combustion （HPDAC） conditions using an in-house computer program. It was found that by applying a combined diluted fuel and oxidant instead of their uncombined and/or undiluted states, the best condition is obtained for the establishment of HPDAC＇s main unique features. These features are low mean and maximum gas temperature and high radiation/total heat transfer to gas and tubes; as well as more uniformity of theirs distributions which results in decrease in NOx pollutant formation and increase in furnace efficiency or energy saving. Moreover, a variety of chemical flame shape, the process fluid and tubes walls temperatures profiles, the required regenerator efficiency and finally the concentration and velocity patterns have been also qualitatively/quantitatively studied.
基金supported by the UK Physical Sciences Research Council under Grant No.EP/X019551/1.
文摘The physicochemical properties of liquid alternative fuels are important but difficult to measure/predict, especially when complex surrogate fuels are concerned. In the present work, machine learning is used to develop quantitative structure–property relationship models. The fuel chemical structure is represented by molecular descriptors, allowing the linking of important features of the fuel composition and key properties of fuel utilization. Feature selection is employed to select the most relevant features that describe the chemical structure of the fuel and several machine learning algorithms are tested to construct interpretable models. The effectiveness of the methodology is demonstrated through the development of accurate and interpretable predictive models for cetane numbers, with a focus on understanding the link between molecular structure and fuel properties. In this context, matrix-based descriptors and descriptors related to the number of atoms in the molecule are directly linked with the cetane number of hydrocarbons. Furthermore, the results showed that molecular connectivity indices play a role in the cetane number for aromatic molecules. Also, the methodology is extended to predict the cetane number of ester and ether molecules, leveraging the design of alternative fuels towards fully sustainable fuel utilization.
基金the National Natural Science Foundation of China(Grant Nos.22032003 and 22072073).
文摘Self-assembly has been extensively studied in chemistry,physics,biology,and materials engineering and has become an important“bottom-up”approach in creating intriguing structures for different applications.Using dissipative self-assembly to construct fuel-dependent,energy-consuming,and dynamic nonequilibrium systems is important for developing intelligent life-like materials.Furthermore,dissipative self-assembly has become a research hotspot in materials chemistry,biomedical science,environmental chemistry,and physical chemistry.An in-depth understanding of the process and mechanism provides useful insights to the researchers for devel-oping materials using dissipative self-assembly and also helps guide future innovation in material fabrication.This critical review comprehensively analyzes various chemical fuel input and energy consumption mechanisms,supported by numerous illustrative examples.Versatile transient assemblies,including gels,vesicles,micelles,and nanoparticle aggregates,have been systematically studied in our and other laboratories.The relationship between the molecular structure of precursors and temporal assemblies in dissipative self-assemblies is discussed from the perspective of physical chemistry.Using dissipative self-assembly methods to construct functional assemblies provides important implications for constructing high-energy,nonequilibrium,and intelligent functional materials.
基金Project supported by National Nuclear Technology Program of National Research Foundation (NRF)Ministry of Education, Science and Technology (MEST), Korean Government
文摘The intermetallic compounds formation at interface between rare earth elements and clad material were investigated to demonstrate the effects of rare earth elements on fuel-cladding chemical interaction （FCCI） behavior. Mischmetal （70Ce-30La） and Nd were prepared as rare earth elements. Diffusion couple testing was performed on the rare earth elements and cladding （9Cr2W steel） near the operation temperature of （sodium-cooled fast reactor） SFR fuel. The performance of a diffusion barrier consisting of Zr and V metallic foil against the rare earth elements was also evaluated. Our results showed that Ce and Nd in the rare earth elements and Fe in the clad material interdiffused and reacted to form intermetallic species according to the parabolic rate law, describing the migration of the rare earth element. The diffusion of Fe limited the reaction progress such that the entire process was governed by the cubic rate law. Rare earth materials could be used as a surrogate for high burnup metallic fuels, and the performance of the barrier material was demonstrated to be effective.
文摘Photocatalytic splitting of water was carried out in a two-phase system. Nanocrystalline titanium dioxide was used as photocatalyst and potassium hexacyanoferrate(III)/(II) as electron transporter. Generated hydrogen was chemically stored by use of a 1,4-benzoquinone/1,4-hydroquinone system, which was used as a recyclable fuel in a commercialised direct methanol fuel cell (DMFC). The electrical output of the cell was about half compared to methanol. The conversion process for water splitting and recombination in a fuel cell was monitored by UV-Vis spectroscopy and compared to a simulated spectrum. Products of side reactions, which lead to a decrease of the overall efficiency, were identified based on UV-Vis investigations. A proof of principle for the use of quinoide systems as a recyclable hydrogen storage system in a photocatalytic water splitting and fuel cell cyclic process was given.
