A self-invented atomization process, in which molten metal is atomized into powder by a high-velocity gas stream carrying solid particles as the atomization medium, was introduced. The characteristics of powders prepa...A self-invented atomization process, in which molten metal is atomized into powder by a high-velocity gas stream carrying solid particles as the atomization medium, was introduced. The characteristics of powders prepared by common gas atomization and dual-phase flow atomization under similar conditions were compared. The experimental results show that the dual-phase flow-atomized powders have average particle sizes that are one-half that of the common gas-atomized particles;additionally, they possess a finer microstructure and higher cooling rate under the same atomization gas pressure and the same gas flow. The Weber number in the crash criteria of liquid atomization is adopted to measure the crash ability of the atomization media. The Weber number of the dual-phase flow atomization medium is the sum of that of the gas and the solid particles. Furthermore, the critical equation of the crash model in dual-phase flow atomization is established, and the main regularities associated with this process were analyzed.展开更多
The depletion of energy and increasing environmental pressure have become one of the main challenges in the world today.Synthetic high-efficiency catalysts bring hope for efficient conversion of energy and effective t...The depletion of energy and increasing environmental pressure have become one of the main challenges in the world today.Synthetic high-efficiency catalysts bring hope for efficient conversion of energy and effective treatment of pollutants,especially,single-atom catalysts(SACs)are promising candidates.Herein,we comprehensively summarizes the atomic diffusion strategy,which is considered as an effective method to prepare a series of SACs.According to the different diffusion forms of the precursors,we review the synthesis pathways of SACs from three aspects:gas diffusion,solid diffusion and liquid diffusion.The gaseous diffusion method mainly discusses atomic layer deposition(ALD)and chemical vapor deposition(CVD),both of which carry out gas phase mass transfer at high temperatures.The solid-state diffusion method can be divided into nanoparticle transformation into single atoms and solid atom migration.Liquid diffusion mainly describes the electrochemical method and the molten salt method.We hope this review can trigger the rational design of SACs.展开更多
文摘A self-invented atomization process, in which molten metal is atomized into powder by a high-velocity gas stream carrying solid particles as the atomization medium, was introduced. The characteristics of powders prepared by common gas atomization and dual-phase flow atomization under similar conditions were compared. The experimental results show that the dual-phase flow-atomized powders have average particle sizes that are one-half that of the common gas-atomized particles;additionally, they possess a finer microstructure and higher cooling rate under the same atomization gas pressure and the same gas flow. The Weber number in the crash criteria of liquid atomization is adopted to measure the crash ability of the atomization media. The Weber number of the dual-phase flow atomization medium is the sum of that of the gas and the solid particles. Furthermore, the critical equation of the crash model in dual-phase flow atomization is established, and the main regularities associated with this process were analyzed.
基金This work was supported by the National Natural Science Foundation of China(No.21801015)Beijing Institute of Technology Research Fund Program for Young Scholars.
文摘The depletion of energy and increasing environmental pressure have become one of the main challenges in the world today.Synthetic high-efficiency catalysts bring hope for efficient conversion of energy and effective treatment of pollutants,especially,single-atom catalysts(SACs)are promising candidates.Herein,we comprehensively summarizes the atomic diffusion strategy,which is considered as an effective method to prepare a series of SACs.According to the different diffusion forms of the precursors,we review the synthesis pathways of SACs from three aspects:gas diffusion,solid diffusion and liquid diffusion.The gaseous diffusion method mainly discusses atomic layer deposition(ALD)and chemical vapor deposition(CVD),both of which carry out gas phase mass transfer at high temperatures.The solid-state diffusion method can be divided into nanoparticle transformation into single atoms and solid atom migration.Liquid diffusion mainly describes the electrochemical method and the molten salt method.We hope this review can trigger the rational design of SACs.
