Electrochemical conversion of carbon dioxide into fuel and chemicals with added value represents an appealing approach to reduce the greenhouse effect and realize a carbon-neutral cycle,which has great potential in mi...Electrochemical conversion of carbon dioxide into fuel and chemicals with added value represents an appealing approach to reduce the greenhouse effect and realize a carbon-neutral cycle,which has great potential in mitigating global warming and effectively storing renewable energy.The electrochemical CO_(2) reduction reaction(CO_(2)RR)usually involves multiproton coupling and multielectron transfer in aqueous electrolytes to form multicarbon products(C_(2+) products),but it competes with the hydrogen evolution reaction(HER),which results in intrinsically sluggish kinetics and a complex reaction mechanism and places higher requirements on the design of catalysts.In this review,the advantages of electrochemical CO_(2) reduction are briefly introduced,and then,different categories of Cu-based catalysts,including monometallic Cu catalysts,bimetallic catalysts,metal-organic frameworks(MOFs)along with MOF-derived catalysts and other catalysts,are summarized in terms of their synthesis method and conversion of CO_(2) to C2+products in aqueous solution.The catalytic mechanisms of these catalysts are subsequently discussed for rational design of more efficient catalysts.In response to the mechanisms,several material strategies to enhance the catalytic behaviors are proposed,including surface facet engineering,interface engineering,utilization of strong metal-support interactions and surface modification.Based on the above strategies,challenges and prospects are proposed for the future development of CO_(2)RR catalysts for industrial applications.展开更多
With the increase of system scale, the inherent reliability of supercomputers becomes lower and lower. The cost of fault handling and task recovery increases so rapidly that the reliability issue will soon harm the us...With the increase of system scale, the inherent reliability of supercomputers becomes lower and lower. The cost of fault handling and task recovery increases so rapidly that the reliability issue will soon harm the usability of supercomputers. This issue is referred to as the ＂reliability wall＂, which is regarded as a critical problem for current and future supercomputers. To address this problem, we propose an autonomous fault-tolerant system, named Iaso, in MilkyWay- 2 system. Iaso introduces the concept of autonomous management in supercomputers. By autonomous management, the computer itself, rather than manpower, takes charge of the fault management work. Iaso automatically manage the whole lifecycle of faults, including fault detection, fault diagnosis, fault isolation, and task recovery. Iaso endows the autonomous features with MilkyWay-2 system, such as self-awareness, self-diagnosis, self-healing, and self-protection. With the help of Iaso, the cost of fault handling in supercomputers reduces from several hours to a few seconds. Iaso greatly improves the usability and reliability of MilkyWay-2 system.展开更多
Two-dimensional MXene has recently captured widespread research attention in energy storage and conversion fields due to its high conductivity,large specific surface area,and remarkable electro-activity.However,its pe...Two-dimensional MXene has recently captured widespread research attention in energy storage and conversion fields due to its high conductivity,large specific surface area,and remarkable electro-activity.However,its performance is still hindered by severe self-restacking of MXene flakes.Herein,conductive Ti_(3)C_(2)T_(x)/carbon nanofiber(CNF)composite aerogel with typical“layer-strut”bracing 3D microscopic architecture has been fabricated via synergistic assembly and freeze-drying process.In virtu of the strong interfacial interaction between polymeric precursor nanofibers and MXene mono-layers,gelation capability and 3D formability of Ti_(3)C_(2)T_(x) is greatly reinforced,as resulted Ti_(3)C_(2)T_(x)/CNF aerogels possess a highly ordered microporous structure with interlayered CNF penetrating between large size MXene lamellae.This special configuration guarantees the stability and pliability of the composite aerogels.Furthermore,the 3D form interconnected conductive network and the parallell alignment of the pores allow free electrical carriers motion and ion migration.As a result,the prepared Ti_(3)C_(2)T_(x)/CNF aerogel-based electrode exhibits an exceptional gravimetric specific capacitance of 268 F g^(−1) at a current density of 0.5 A g^(−1) and an excellent cycling stability of 8000 cylcles,and the assembled symmetric supercapacitor,delivers a high energy density of 3.425 W h kg^(−1) at 6000 W kg^(−1).This work offers a new route for the rational construction of 3D MXene assembly for advanced energy storage materials.展开更多
基金supported by the Higher Education Discipline Innovation Project(Grant No.D17007)Henan Center for Outstanding Overseas Scientists(Grant No.GZS2022017)+2 种基金National Science Foundation of China(Grant Nos.21908045,51922008,52072114 and 51872075)China Postdoctoral Science Foundation(Grant No.2018M642754)Talent Postdoctoral Program for Henan Province(Grant No.ZYQR201810170).
文摘Electrochemical conversion of carbon dioxide into fuel and chemicals with added value represents an appealing approach to reduce the greenhouse effect and realize a carbon-neutral cycle,which has great potential in mitigating global warming and effectively storing renewable energy.The electrochemical CO_(2) reduction reaction(CO_(2)RR)usually involves multiproton coupling and multielectron transfer in aqueous electrolytes to form multicarbon products(C_(2+) products),but it competes with the hydrogen evolution reaction(HER),which results in intrinsically sluggish kinetics and a complex reaction mechanism and places higher requirements on the design of catalysts.In this review,the advantages of electrochemical CO_(2) reduction are briefly introduced,and then,different categories of Cu-based catalysts,including monometallic Cu catalysts,bimetallic catalysts,metal-organic frameworks(MOFs)along with MOF-derived catalysts and other catalysts,are summarized in terms of their synthesis method and conversion of CO_(2) to C2+products in aqueous solution.The catalytic mechanisms of these catalysts are subsequently discussed for rational design of more efficient catalysts.In response to the mechanisms,several material strategies to enhance the catalytic behaviors are proposed,including surface facet engineering,interface engineering,utilization of strong metal-support interactions and surface modification.Based on the above strategies,challenges and prospects are proposed for the future development of CO_(2)RR catalysts for industrial applications.
基金Acknowledgements This work was partially supported by National High-tech R＆D Program of China （863 Program） （2012AA01A301, 2012AA010901）, by Program for New Century Excellent Talents in University and by National Natural Science Foundation of China （Grant Nos. 61272142, 61103082, 61170261, and 61103193）.
文摘With the increase of system scale, the inherent reliability of supercomputers becomes lower and lower. The cost of fault handling and task recovery increases so rapidly that the reliability issue will soon harm the usability of supercomputers. This issue is referred to as the ＂reliability wall＂, which is regarded as a critical problem for current and future supercomputers. To address this problem, we propose an autonomous fault-tolerant system, named Iaso, in MilkyWay- 2 system. Iaso introduces the concept of autonomous management in supercomputers. By autonomous management, the computer itself, rather than manpower, takes charge of the fault management work. Iaso automatically manage the whole lifecycle of faults, including fault detection, fault diagnosis, fault isolation, and task recovery. Iaso endows the autonomous features with MilkyWay-2 system, such as self-awareness, self-diagnosis, self-healing, and self-protection. With the help of Iaso, the cost of fault handling in supercomputers reduces from several hours to a few seconds. Iaso greatly improves the usability and reliability of MilkyWay-2 system.
基金This work is financially supported by the National Natural Science Foundation of China(No.21875033)the Shanghai Scientific and Technological Innovation Project(No.18JC1410600)+1 种基金the Program of the Shanghai Academic Research Leader(No.17XD1400100)the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials(Donghua University).
文摘Two-dimensional MXene has recently captured widespread research attention in energy storage and conversion fields due to its high conductivity,large specific surface area,and remarkable electro-activity.However,its performance is still hindered by severe self-restacking of MXene flakes.Herein,conductive Ti_(3)C_(2)T_(x)/carbon nanofiber(CNF)composite aerogel with typical“layer-strut”bracing 3D microscopic architecture has been fabricated via synergistic assembly and freeze-drying process.In virtu of the strong interfacial interaction between polymeric precursor nanofibers and MXene mono-layers,gelation capability and 3D formability of Ti_(3)C_(2)T_(x) is greatly reinforced,as resulted Ti_(3)C_(2)T_(x)/CNF aerogels possess a highly ordered microporous structure with interlayered CNF penetrating between large size MXene lamellae.This special configuration guarantees the stability and pliability of the composite aerogels.Furthermore,the 3D form interconnected conductive network and the parallell alignment of the pores allow free electrical carriers motion and ion migration.As a result,the prepared Ti_(3)C_(2)T_(x)/CNF aerogel-based electrode exhibits an exceptional gravimetric specific capacitance of 268 F g^(−1) at a current density of 0.5 A g^(−1) and an excellent cycling stability of 8000 cylcles,and the assembled symmetric supercapacitor,delivers a high energy density of 3.425 W h kg^(−1) at 6000 W kg^(−1).This work offers a new route for the rational construction of 3D MXene assembly for advanced energy storage materials.
