Electrochemical CO_(2)reduction is a typical surface-mediated reaction,with its reaction kinetics and product distributions largely dependent on the dynamic evolution of reactive species at the cathode–catholyte inte...Electrochemical CO_(2)reduction is a typical surface-mediated reaction,with its reaction kinetics and product distributions largely dependent on the dynamic evolution of reactive species at the cathode–catholyte interface and on the resultant mass transport within the hydrodynamic boundary layer in the vicinity of the cathode.To resolve the complex local reaction environment of branching CO_(2)reduction pathways,we here present a dif-ferential electrochemical mass spectroscopic(DEMS)approach for Cu electrodes to investigate CO_(2)mass trans-port,the local concentration gradients of buffering anions,and the Cu surface topology effects on CO_(2)electrolysis selectivity at a temporal resolution of~400 ms.As a proof of concept,these tuning knobs were validated on an anion exchange membrane electrolyzer,which delivered a Faradaic efficiency of up to 40.4%and a partial current density of 121 mA cm^(-2)for CO_(2)-to-C_(2)H_(4)valorization.This methodology,which bridges the study of fundamental surface electrochemistry and the upgrading of practical electrolyzer performance,could be of general interest in helping to achieve a sustainable circular carbon economy.展开更多
Large scale synthesis of high-efficiency bifunctional electrocatalyst based on cost-effective and earth-abundant transition metal for overall water splitting in the alkaline environment is indispensable for renewable ...Large scale synthesis of high-efficiency bifunctional electrocatalyst based on cost-effective and earth-abundant transition metal for overall water splitting in the alkaline environment is indispensable for renewable energy conversion.In this regard,meticulous design of active sites and probing their catalytic mechanism on both cathode and anode with different reaction environment at molecular-scale are vitally necessary.Herein,a coordination environment inheriting strategy is presented for designing low-coordination Ni^(2+)octahedra(L-Ni-8)atomic interface at a high concentration(4.6 at.%).Advanced spectroscopic techniques and theoretical calculations reveal that the self-matching electron delocalization and localization state at L-Ni-8 atomic interface enable an ideal reaction environment at both cathode and anode.To improve the efficiency of using the self-modification reaction environment at L-Ni-8,all of the structural features,including high atom economy,mass transfer,and electron transfer,are integrated together from atomic-scale to macro-scale.At high current density of 500 mA/cm2,the samples synthesized at gram-scale can deliver low hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)overpotentials of 262 and 348 mV,respectively.展开更多
To develop more efficient chemical methods for the demineralization of organic pollutants from water bodies, which one was also mimic to the nature, a degradation of methylene blue by Fe(Ⅲ) and H 2O 2 in the absenc...To develop more efficient chemical methods for the demineralization of organic pollutants from water bodies, which one was also mimic to the nature, a degradation of methylene blue by Fe(Ⅲ) and H 2O 2 in the absence of light instead of Fe(Ⅱ) and H 2O 2 was studied. Results showed that use of Fe (Ⅲ) is more promising than Fe(Ⅱ). The present study reflects that Fenton reaction is more efficient, in the presence of a small amount of salicylic acid is added which is a one of the priority pollutant.展开更多
The effect of boron doping on the sensitivity to environmental embrittlement of Ni3Al-based alloys was investigated in this paper. The results show that the ductilizing effect of boron in Ni3Al is partly to suppress ...The effect of boron doping on the sensitivity to environmental embrittlement of Ni3Al-based alloys was investigated in this paper. The results show that the ductilizing effect of boron in Ni3Al is partly to suppress moisture-induced hydrogen embrittlement.The mechanism of this suppressing effect of boron relates to its severely decreasing the hydrogen diffusivity by boron segregated at the grain boundaries. The surface reaction of Fe3Al with water vapor and oxygen was experimentally confirmed by AES and XPS analysis. The kinetics of these reactions can be used to explain the different ductility behavior of aluminides in various environments.展开更多
In this study, we present a Pareto-based chemicalreaction optimization(PCRO) algorithm for solving the multiarea environmental/economic dispatch optimization problems.Two objectives are minimized simultaneously, i.e.,...In this study, we present a Pareto-based chemicalreaction optimization(PCRO) algorithm for solving the multiarea environmental/economic dispatch optimization problems.Two objectives are minimized simultaneously, i.e., total fuel cost and emission. In the proposed algorithm, each solution is represented by a chemical molecule. A novel encoding mechanism for solving the multi-area environmental/economic dispatch optimization problems is designed to dynamically enhance the performance of the proposed algorithm. Then, an ensemble of effective neighborhood approaches is developed, and a selfadaptive neighborhood structure selection mechanism is also embedded in PCRO to increase the search ability while maintaining population diversity. In addition, a grid-based crowding distance strategy is introduced, which can obviously enable the algorithm to easily converge near the Pareto front. Furthermore,a kinetic-energy-based search procedure is developed to enhance the global search ability. Finally, the proposed algorithm is tested on sets of the instances that are generated based on realistic production. Through the analysis of experimental results, the highly effective performance of the proposed PCRO algorithm is favorably compared with several algorithms, with regards to both solution quality and diversity.展开更多
A series of 5-arylidene thiobarbituric acids were prepared from aromatic aldehydes and thiobarbituric acid in water without catalyst conditions in good yields. The structures were characterized by elemental analysis,...A series of 5-arylidene thiobarbituric acids were prepared from aromatic aldehydes and thiobarbituric acid in water without catalyst conditions in good yields. The structures were characterized by elemental analysis, IR and 1H NMR spectra.展开更多
The mechanism involving the effect of disorder/order transformation on the environmental embrittlement in gaseous H2 is summarized. It is shown that there is no hydrogen embrittlement in disordered state of Kurnakov t...The mechanism involving the effect of disorder/order transformation on the environmental embrittlement in gaseous H2 is summarized. It is shown that there is no hydrogen embrittlement in disordered state of Kurnakov type intermetallics in gaseous H2. However, the H2-induced environmental embrittlement for the ordered alloy having identical chemical composition becomes severer as the degree of the order increases. The results of testing on the ion gage turned on and off during tensile testing show that the more sensitive to H2-induced hydrogen embrittlement for ordered alloy than disordered one is attributed to the fact that atomic ordering may accelerate the kinetics of the catalytic reaction to produce more atomic hydrogen. The results on simultaneous hydrogen charging show that disordered alloys embrittled as hydrogen atoms are forced into the material implying that the embrittlement of ordered alloy in gaseous H2 is also due to the acceleration of the kinetics of catalytic reaction. The above suggestion was further verified by the adsorption tests of Ni3Fe intermetallics powder. It is shown that the amount of chemically adsorbed hydrogen in ordered state is significantly larger than that adsorbed by the disordered alloy, indicating that the more sensitive to H2-induced embrittlement in the ordered state of alloy is essentially due to the accelerated catalytic reaction.展开更多
基金supported by the National Key R&D Program of China(2022YFB4102000,2022YFA1505100,2022YFA1503803)the NSFC(22002088)+1 种基金the Shanghai Sailing Program(20YF1420500)the Shanghai Science and Technology Innovation Action Plan(22dz1205500).
文摘Electrochemical CO_(2)reduction is a typical surface-mediated reaction,with its reaction kinetics and product distributions largely dependent on the dynamic evolution of reactive species at the cathode–catholyte interface and on the resultant mass transport within the hydrodynamic boundary layer in the vicinity of the cathode.To resolve the complex local reaction environment of branching CO_(2)reduction pathways,we here present a dif-ferential electrochemical mass spectroscopic(DEMS)approach for Cu electrodes to investigate CO_(2)mass trans-port,the local concentration gradients of buffering anions,and the Cu surface topology effects on CO_(2)electrolysis selectivity at a temporal resolution of~400 ms.As a proof of concept,these tuning knobs were validated on an anion exchange membrane electrolyzer,which delivered a Faradaic efficiency of up to 40.4%and a partial current density of 121 mA cm^(-2)for CO_(2)-to-C_(2)H_(4)valorization.This methodology,which bridges the study of fundamental surface electrochemistry and the upgrading of practical electrolyzer performance,could be of general interest in helping to achieve a sustainable circular carbon economy.
基金supported by the National Natural Science Foundation of China(No.21676300)the Shandong Provincial Natural Science Foundation(No.ZR2018MB035)+3 种基金the Fundamental Research Funds for the Central Universities(Nos.19CX02008A and 16CX06007A)PetroChina Innovation Foundation(No.2019D-5007-0401)Taishan Scholars Program of Shandong Province(No.tsqn201909065)Tsinghua University Initiative Scientific Research Program.
文摘Large scale synthesis of high-efficiency bifunctional electrocatalyst based on cost-effective and earth-abundant transition metal for overall water splitting in the alkaline environment is indispensable for renewable energy conversion.In this regard,meticulous design of active sites and probing their catalytic mechanism on both cathode and anode with different reaction environment at molecular-scale are vitally necessary.Herein,a coordination environment inheriting strategy is presented for designing low-coordination Ni^(2+)octahedra(L-Ni-8)atomic interface at a high concentration(4.6 at.%).Advanced spectroscopic techniques and theoretical calculations reveal that the self-matching electron delocalization and localization state at L-Ni-8 atomic interface enable an ideal reaction environment at both cathode and anode.To improve the efficiency of using the self-modification reaction environment at L-Ni-8,all of the structural features,including high atom economy,mass transfer,and electron transfer,are integrated together from atomic-scale to macro-scale.At high current density of 500 mA/cm2,the samples synthesized at gram-scale can deliver low hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)overpotentials of 262 and 348 mV,respectively.
文摘To develop more efficient chemical methods for the demineralization of organic pollutants from water bodies, which one was also mimic to the nature, a degradation of methylene blue by Fe(Ⅲ) and H 2O 2 in the absence of light instead of Fe(Ⅱ) and H 2O 2 was studied. Results showed that use of Fe (Ⅲ) is more promising than Fe(Ⅱ). The present study reflects that Fenton reaction is more efficient, in the presence of a small amount of salicylic acid is added which is a one of the priority pollutant.
文摘The effect of boron doping on the sensitivity to environmental embrittlement of Ni3Al-based alloys was investigated in this paper. The results show that the ductilizing effect of boron in Ni3Al is partly to suppress moisture-induced hydrogen embrittlement.The mechanism of this suppressing effect of boron relates to its severely decreasing the hydrogen diffusivity by boron segregated at the grain boundaries. The surface reaction of Fe3Al with water vapor and oxygen was experimentally confirmed by AES and XPS analysis. The kinetics of these reactions can be used to explain the different ductility behavior of aluminides in various environments.
基金partially supported by the National Natural Science Foundation of China(61773192,61773246,61603169,61803192)Shandong Province Higher Educational Science and Technology Program(J17KZ005)+1 种基金Special Fund Plan for Local Science and Technology Development Lead by Central AuthorityMajor Basic Research Projects in Shandong(ZR2018ZB0419)
文摘In this study, we present a Pareto-based chemicalreaction optimization(PCRO) algorithm for solving the multiarea environmental/economic dispatch optimization problems.Two objectives are minimized simultaneously, i.e., total fuel cost and emission. In the proposed algorithm, each solution is represented by a chemical molecule. A novel encoding mechanism for solving the multi-area environmental/economic dispatch optimization problems is designed to dynamically enhance the performance of the proposed algorithm. Then, an ensemble of effective neighborhood approaches is developed, and a selfadaptive neighborhood structure selection mechanism is also embedded in PCRO to increase the search ability while maintaining population diversity. In addition, a grid-based crowding distance strategy is introduced, which can obviously enable the algorithm to easily converge near the Pareto front. Furthermore,a kinetic-energy-based search procedure is developed to enhance the global search ability. Finally, the proposed algorithm is tested on sets of the instances that are generated based on realistic production. Through the analysis of experimental results, the highly effective performance of the proposed PCRO algorithm is favorably compared with several algorithms, with regards to both solution quality and diversity.
基金the Natural Science Foundation of Shaan’xi Province(No.2000H03)for support of this work.
文摘A series of 5-arylidene thiobarbituric acids were prepared from aromatic aldehydes and thiobarbituric acid in water without catalyst conditions in good yields. The structures were characterized by elemental analysis, IR and 1H NMR spectra.
基金Project supported by the National Natural Science Foundation of China （Grant Nos.50371050, 59895157, 59681002, 59771007）
文摘The mechanism involving the effect of disorder/order transformation on the environmental embrittlement in gaseous H2 is summarized. It is shown that there is no hydrogen embrittlement in disordered state of Kurnakov type intermetallics in gaseous H2. However, the H2-induced environmental embrittlement for the ordered alloy having identical chemical composition becomes severer as the degree of the order increases. The results of testing on the ion gage turned on and off during tensile testing show that the more sensitive to H2-induced hydrogen embrittlement for ordered alloy than disordered one is attributed to the fact that atomic ordering may accelerate the kinetics of the catalytic reaction to produce more atomic hydrogen. The results on simultaneous hydrogen charging show that disordered alloys embrittled as hydrogen atoms are forced into the material implying that the embrittlement of ordered alloy in gaseous H2 is also due to the acceleration of the kinetics of catalytic reaction. The above suggestion was further verified by the adsorption tests of Ni3Fe intermetallics powder. It is shown that the amount of chemically adsorbed hydrogen in ordered state is significantly larger than that adsorbed by the disordered alloy, indicating that the more sensitive to H2-induced embrittlement in the ordered state of alloy is essentially due to the accelerated catalytic reaction.
