Construction of catalysts with integral structure for oxidative reaction process is an essential promotion to catalysts in industrial application.In this work,a 3D printing method was employed to prepare 3D printed sp...Construction of catalysts with integral structure for oxidative reaction process is an essential promotion to catalysts in industrial application.In this work,a 3D printing method was employed to prepare 3D printed spheres(3D-PSs),followed by carbonization to form 3D carbon spheres(3D-CSs).Then,a 3D-CSs supported phosphotungstic acid(HPW/3D-CSs)was prepared for deep oxidative desulfurization.Compared with traditional powder catalysts,the as-prepared catalyst is easy to be operated and separated from oil products.The supported catalyst possesses excellent catalytic performance and the removal of DBT,4-MDBT and 4,6-DMDBT in fuel oil,reaching^100%of sulfur removal.The effects of various experimental parameters on desulfurization efficiency were considered to optimize reaction conditions.Moreover,the catalyst shows excellent thermal and chemical stability,with no obvious decrease in desulfurization activity after 5 cycles.GC–MS analysis indicates DBT sulfone was the solely oxidized product of DBT.展开更多
A liquid Li divertor is a promising alternative for future fusion devices.In this work a new divertor model is proposed,which is processed by 3D-printing technology to accurately control the size of the internal capil...A liquid Li divertor is a promising alternative for future fusion devices.In this work a new divertor model is proposed,which is processed by 3D-printing technology to accurately control the size of the internal capillary structure.At a steady-state heat load of 10 MW m^(-2),the thermal stress of the tungsten target is within the bearing range of tungsten by finite-element simulation.In order to evaluate the wicking ability of the capillary structure,the wicking process at 600℃ was simulated by FLUENT.The result was identical to that of the corresponding experiments.Within 1 s,liquid lithium was wicked to the target surface by the capillary structure of the target and quickly spread on the target surface.During the wicking process,the average wicking mass rate of lithium should reach 0.062 g s^(-1),which could even supplement the evaporation requirement of liquid lithium under an environment>950℃.Irradiation experiments under different plasma discharge currents were carried out in a linear plasma device(SCU-PSI),and the evolution of the vapor cloud during plasma irradiation was analyzed.It was found that the target temperature tends to plateau despite the gradually increased input current,indicating that the vapor shielding effect is gradually enhanced.The irradiation experiment also confirmed that the 3D-printed tungsten structure has better heat consumption performance than a tungsten mesh structure or multichannel structure.These results reveal the application potential and feasibility of a 3D-printed porous capillary structure in plasma-facing components and provide a reference for further liquid-solid combined target designs.展开更多
Metal-organic frameworks(MOFs)have been extensively considered as one of the most promising types of porous and crystalline organic-inorganic materials,thanks to their large specific surface area,high porosity,tailora...Metal-organic frameworks(MOFs)have been extensively considered as one of the most promising types of porous and crystalline organic-inorganic materials,thanks to their large specific surface area,high porosity,tailorable structures and compositions,diverse functionalities,and well-controlled pore/size distribution.However,most developed MOFs are in powder forms,which still have some technical challenges,including abrasion,dustiness,low packing densities,clogging,mass/heat transfer limitation,environmental pollution,and mechanical instability during the packing process,that restrict their applicability in industrial applications.Therefore,in recent years,attention has focused on techniques to convert MOF powders into macroscopic materials like beads,membranes,monoliths,gel/sponges,and nanofibers to overcome these challenges.Three-dimensional(3D)printing technology has achieved much interest because it can produce many high-resolution macroscopic frameworks with complex shapes and geometries from digital models.Therefore,this review summarizes the combination of different 3D printing strategies with MOFs and MOF-based materials for fabricating 3D-printed MOF monoliths and their environmental applications,emphasizing water treatment and gas adsorption/separation applications.Herein,the various strategies for the fabrication of 3D-printed MOF monoliths,such as direct ink writing,seed-assisted in-situ growth,coordination replication from solid precursors,matrix incorporation,selective laser sintering,and digital light processing,are described with the relevant examples.Finally,future directions and challenges of 3D-printed MOF monoliths are also presented to better plan future trajectories in the shaping of MOF materials with improved control over the structure,composition,and textural properties of 3D-printed MOF monoliths.展开更多
β-Ga_(2)O_(3)是一种具有超宽带隙、高临界击穿场强和优异的巴利加优值的半导体材料,近年来在电力电子与深紫外光电探测等领域展现出巨大的应用潜力。金属有机化学气相沉积(Metal-organic chemical vapor deposition,MOCVD)技术凭借其...β-Ga_(2)O_(3)是一种具有超宽带隙、高临界击穿场强和优异的巴利加优值的半导体材料,近年来在电力电子与深紫外光电探测等领域展现出巨大的应用潜力。金属有机化学气相沉积(Metal-organic chemical vapor deposition,MOCVD)技术凭借其高生长速率、精确的膜厚控制、优异的薄膜质量和大尺寸生长等优势,成为未来β-Ga_(2)O_(3)走向产业化的潜在方法,并已被广泛应用于β-Ga_(2)O_(3)的外延生长研究。本文对几种常见晶向的β-Ga_(2)O_(3) MOCVD同质外延生长的研究成果进行了概述,并在此基础上介绍了极具潜力的β-(Al_(x)Ga_(1-x))_(2)O_(3)的MOCVD外延生长研究现状。最后,总结了基于MOCVD技术的β-Ga_(2)O_(3)同质外延生长以及β-(Al_(x)Ga_(1-x))_(2)O_(3)生长过程中面临的主要问题,并对未来的发展进行了展望。展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21722604,21576122,21878133)China Postdoctoral Science Foundation(No.2019M651743)。
文摘Construction of catalysts with integral structure for oxidative reaction process is an essential promotion to catalysts in industrial application.In this work,a 3D printing method was employed to prepare 3D printed spheres(3D-PSs),followed by carbonization to form 3D carbon spheres(3D-CSs).Then,a 3D-CSs supported phosphotungstic acid(HPW/3D-CSs)was prepared for deep oxidative desulfurization.Compared with traditional powder catalysts,the as-prepared catalyst is easy to be operated and separated from oil products.The supported catalyst possesses excellent catalytic performance and the removal of DBT,4-MDBT and 4,6-DMDBT in fuel oil,reaching^100%of sulfur removal.The effects of various experimental parameters on desulfurization efficiency were considered to optimize reaction conditions.Moreover,the catalyst shows excellent thermal and chemical stability,with no obvious decrease in desulfurization activity after 5 cycles.GC–MS analysis indicates DBT sulfone was the solely oxidized product of DBT.
基金funded by the China Postdoctoral Science Foundation(No.2019M663487)the National Key Research and Development Program of China(No.2022YFE03130000)。
文摘A liquid Li divertor is a promising alternative for future fusion devices.In this work a new divertor model is proposed,which is processed by 3D-printing technology to accurately control the size of the internal capillary structure.At a steady-state heat load of 10 MW m^(-2),the thermal stress of the tungsten target is within the bearing range of tungsten by finite-element simulation.In order to evaluate the wicking ability of the capillary structure,the wicking process at 600℃ was simulated by FLUENT.The result was identical to that of the corresponding experiments.Within 1 s,liquid lithium was wicked to the target surface by the capillary structure of the target and quickly spread on the target surface.During the wicking process,the average wicking mass rate of lithium should reach 0.062 g s^(-1),which could even supplement the evaporation requirement of liquid lithium under an environment>950℃.Irradiation experiments under different plasma discharge currents were carried out in a linear plasma device(SCU-PSI),and the evolution of the vapor cloud during plasma irradiation was analyzed.It was found that the target temperature tends to plateau despite the gradually increased input current,indicating that the vapor shielding effect is gradually enhanced.The irradiation experiment also confirmed that the 3D-printed tungsten structure has better heat consumption performance than a tungsten mesh structure or multichannel structure.These results reveal the application potential and feasibility of a 3D-printed porous capillary structure in plasma-facing components and provide a reference for further liquid-solid combined target designs.
文摘Metal-organic frameworks(MOFs)have been extensively considered as one of the most promising types of porous and crystalline organic-inorganic materials,thanks to their large specific surface area,high porosity,tailorable structures and compositions,diverse functionalities,and well-controlled pore/size distribution.However,most developed MOFs are in powder forms,which still have some technical challenges,including abrasion,dustiness,low packing densities,clogging,mass/heat transfer limitation,environmental pollution,and mechanical instability during the packing process,that restrict their applicability in industrial applications.Therefore,in recent years,attention has focused on techniques to convert MOF powders into macroscopic materials like beads,membranes,monoliths,gel/sponges,and nanofibers to overcome these challenges.Three-dimensional(3D)printing technology has achieved much interest because it can produce many high-resolution macroscopic frameworks with complex shapes and geometries from digital models.Therefore,this review summarizes the combination of different 3D printing strategies with MOFs and MOF-based materials for fabricating 3D-printed MOF monoliths and their environmental applications,emphasizing water treatment and gas adsorption/separation applications.Herein,the various strategies for the fabrication of 3D-printed MOF monoliths,such as direct ink writing,seed-assisted in-situ growth,coordination replication from solid precursors,matrix incorporation,selective laser sintering,and digital light processing,are described with the relevant examples.Finally,future directions and challenges of 3D-printed MOF monoliths are also presented to better plan future trajectories in the shaping of MOF materials with improved control over the structure,composition,and textural properties of 3D-printed MOF monoliths.
文摘β-Ga_(2)O_(3)是一种具有超宽带隙、高临界击穿场强和优异的巴利加优值的半导体材料,近年来在电力电子与深紫外光电探测等领域展现出巨大的应用潜力。金属有机化学气相沉积(Metal-organic chemical vapor deposition,MOCVD)技术凭借其高生长速率、精确的膜厚控制、优异的薄膜质量和大尺寸生长等优势,成为未来β-Ga_(2)O_(3)走向产业化的潜在方法,并已被广泛应用于β-Ga_(2)O_(3)的外延生长研究。本文对几种常见晶向的β-Ga_(2)O_(3) MOCVD同质外延生长的研究成果进行了概述,并在此基础上介绍了极具潜力的β-(Al_(x)Ga_(1-x))_(2)O_(3)的MOCVD外延生长研究现状。最后,总结了基于MOCVD技术的β-Ga_(2)O_(3)同质外延生长以及β-(Al_(x)Ga_(1-x))_(2)O_(3)生长过程中面临的主要问题,并对未来的发展进行了展望。
