Plasma-based CO_(2)conversion is promising for carbon capture and utilization.However,inconsistent reporting of the performance metrics makes it difficult to compare plasma processes systematically,complicates elucida...Plasma-based CO_(2)conversion is promising for carbon capture and utilization.However,inconsistent reporting of the performance metrics makes it difficult to compare plasma processes systematically,complicates elucidating the underlying mechanisms and compromises further development of this technology.Therefore,this critical review summarizes the correct definitions for gas conversion in plasma reactors and highlights common errors and inconsistencies observed throughout literature.This is done for pure CO_(2)splitting,dry reforming of methane and CO_(2)hydrogenation.We demonstrate that the change in volumetric flow rate is a critical aspect,inherent to these reactions,that is often not correctly taken into account.For dry reforming of methane and CO_(2)hydrogenation,we also demonstrate inconsistent reporting of energy efficiency,and through numerical examples,we show the significance of these deviations.Furthermore,we discuss how to measure changes in volumetric flow rate,supported by data from two experimental examples,showing that the sensitivity inherent to a standard component and a flow meter is essential to consider when deriving the performance metrics.Finally,some general recommendations and good practices are provided.This paper aims to be a comprehensive guideline for authors,to encourage more consistent calculations and stimulate the further development of this technology.展开更多
The effects of radio frequency(RF)atmospheric pressure(AP)He/H_(2)plasma and thermal treatment on the hydrogenation of TiO_(2)thin films were investigated and compared in this work.The color of the original TiO_(2)fil...The effects of radio frequency(RF)atmospheric pressure(AP)He/H_(2)plasma and thermal treatment on the hydrogenation of TiO_(2)thin films were investigated and compared in this work.The color of the original TiO_(2)film changes from white to black after being hydrogenated in He/H_(2)plasma at160 W(gas temperature~381℃)within 5 min,while the color of the thermally treated TiO_(2)film did not change significantly even in pure H_(2)or He/H_(2)atmosphere with higher temperature(470℃)and longer time(30 min).This indicated that a more effective hydrogenation reaction happened through RF AP He/H_(2)plasma treatment than through pure H_(2)or He/H_(2)thermal treatment.The color change of TiO_(2)film was measured based on the Commission Internationale d’Eclairage L*a*b*color space system.Hydrogenated TiO_(2)film displayed improved visible light absorption with increased plasma power.The morphology of the cauliflower-like nanoparticles of the TiO_(2)film surface remained unchanged after plasma processing.X-ray photoelectron spectroscopy results showed that the contents of Ti3+species and Ti-OH bonds in the plasma-hydrogenated black TiO_(2)increased compared with those in the thermally treated TiO_(2).X-ray diffraction(XRD)patterns and Raman spectra indicated that plasma would destroy the crystal structure of the TiO_(2)surface layer,while thermal annealing would increase the overall crystallinity.The different trends of XRD and Raman spectra results suggested that plasma modification on the TiO_(2)surface layer is more drastic than on its inner layer,which was also consistent with transmission electron microscopy results.Optical emission spectra results suggest that numerous active species were generated during RF AP He/H_(2)plasma processing,while there were no peaks detected from thermal processing.A possible mechanism for the TiO_(2)hydrogenation process by plasma has been proposed.Numerous active species were generated in the bulk plasma region,accelerated in the sheath region,and bumped toward the TiO_(2)film,whic展开更多
At atmospheric pressure and ambient temperature, the hydrogenation coupling of methane was studied by using pulse corona plasma and its synergism with catalyst. The results showed that (i) under pulse corona plasma, t...At atmospheric pressure and ambient temperature, the hydrogenation coupling of methane was studied by using pulse corona plasma and its synergism with catalyst. The results showed that (i) under pulse corona plasma, the coupling of methane could be fulfilled by the addition of hydrogen, and with the increase of the amount of hydrogen, the conversion of methane and the yield of C2 hydrocarbon increased, and the deposit of carbon decreased; (ii) the conversion of methane was affected by pulse voltage and repeated frequency; (iii) in the system, the addition of Ni/γ-Al2O3 could improve the distribution of C2 hydrocarbon; (iv) the activity of Ni/γ-Al2O3 prepared by cold plasma was better than that by chemical methods. The experiment opened up a new technical route of the coupling of methane.展开更多
This work intends to manipulate the internal flow units in Zr_(55)Cu_(30)Ni_(5)Al_(10)bulk-metallic glasses(BMGs)through plasma-assisted hydrogenation to generate a positive microalloying effect on plasticity.Based on...This work intends to manipulate the internal flow units in Zr_(55)Cu_(30)Ni_(5)Al_(10)bulk-metallic glasses(BMGs)through plasma-assisted hydrogenation to generate a positive microalloying effect on plasticity.Based on the cooperative shear model theory,serration-flow statistics during nanoindentation loading and creep tests during the holding stage were used to analyze the influence of hydrogen on the behavior of flow units in BMGs.Experimental observations showed that the hydrogen in the Zr_(55)Cu_(30)Ni_(5)Al_(10)BMGs caused mechanical softening,plasticity improvement,and structural relaxation.Analysis also showed that the average volume,size,and activation energy of internal flow units in the BMGs all increased as a result of the increase in the hydrogen content.The hydrogenation in the BMGs was found to lead to a prolifera-tion of shear bands,which promoted plasticity.The aggregation of these internal flow units reduced the stress required for plastic deformation through shear bands,ultimately causing softening and structural relaxation.展开更多
基金financial support from the Fund for Scientific Research(FWO)Flanders(Grant ID 110221N)the European Research Council(ERC)under the European Union’s Horizon 2020 Research and Innovation Program(grant agreement No 810182-SCOPE ERC Synergy project)the Methusalem funding of the University of Antwerp。
文摘Plasma-based CO_(2)conversion is promising for carbon capture and utilization.However,inconsistent reporting of the performance metrics makes it difficult to compare plasma processes systematically,complicates elucidating the underlying mechanisms and compromises further development of this technology.Therefore,this critical review summarizes the correct definitions for gas conversion in plasma reactors and highlights common errors and inconsistencies observed throughout literature.This is done for pure CO_(2)splitting,dry reforming of methane and CO_(2)hydrogenation.We demonstrate that the change in volumetric flow rate is a critical aspect,inherent to these reactions,that is often not correctly taken into account.For dry reforming of methane and CO_(2)hydrogenation,we also demonstrate inconsistent reporting of energy efficiency,and through numerical examples,we show the significance of these deviations.Furthermore,we discuss how to measure changes in volumetric flow rate,supported by data from two experimental examples,showing that the sensitivity inherent to a standard component and a flow meter is essential to consider when deriving the performance metrics.Finally,some general recommendations and good practices are provided.This paper aims to be a comprehensive guideline for authors,to encourage more consistent calculations and stimulate the further development of this technology.
基金financially supported by National Natural Science Foundation of China(Nos.12075054,12205040,12175036,11875104)。
文摘The effects of radio frequency(RF)atmospheric pressure(AP)He/H_(2)plasma and thermal treatment on the hydrogenation of TiO_(2)thin films were investigated and compared in this work.The color of the original TiO_(2)film changes from white to black after being hydrogenated in He/H_(2)plasma at160 W(gas temperature~381℃)within 5 min,while the color of the thermally treated TiO_(2)film did not change significantly even in pure H_(2)or He/H_(2)atmosphere with higher temperature(470℃)and longer time(30 min).This indicated that a more effective hydrogenation reaction happened through RF AP He/H_(2)plasma treatment than through pure H_(2)or He/H_(2)thermal treatment.The color change of TiO_(2)film was measured based on the Commission Internationale d’Eclairage L*a*b*color space system.Hydrogenated TiO_(2)film displayed improved visible light absorption with increased plasma power.The morphology of the cauliflower-like nanoparticles of the TiO_(2)film surface remained unchanged after plasma processing.X-ray photoelectron spectroscopy results showed that the contents of Ti3+species and Ti-OH bonds in the plasma-hydrogenated black TiO_(2)increased compared with those in the thermally treated TiO_(2).X-ray diffraction(XRD)patterns and Raman spectra indicated that plasma would destroy the crystal structure of the TiO_(2)surface layer,while thermal annealing would increase the overall crystallinity.The different trends of XRD and Raman spectra results suggested that plasma modification on the TiO_(2)surface layer is more drastic than on its inner layer,which was also consistent with transmission electron microscopy results.Optical emission spectra results suggest that numerous active species were generated during RF AP He/H_(2)plasma processing,while there were no peaks detected from thermal processing.A possible mechanism for the TiO_(2)hydrogenation process by plasma has been proposed.Numerous active species were generated in the bulk plasma region,accelerated in the sheath region,and bumped toward the TiO_(2)film,whic
文摘At atmospheric pressure and ambient temperature, the hydrogenation coupling of methane was studied by using pulse corona plasma and its synergism with catalyst. The results showed that (i) under pulse corona plasma, the coupling of methane could be fulfilled by the addition of hydrogen, and with the increase of the amount of hydrogen, the conversion of methane and the yield of C2 hydrocarbon increased, and the deposit of carbon decreased; (ii) the conversion of methane was affected by pulse voltage and repeated frequency; (iii) in the system, the addition of Ni/γ-Al2O3 could improve the distribution of C2 hydrocarbon; (iv) the activity of Ni/γ-Al2O3 prepared by cold plasma was better than that by chemical methods. The experiment opened up a new technical route of the coupling of methane.
基金supported the National Natural Science Foundation of China(51401129)Natural Science Foundation of Liaoning Province(2019-ZD-0216,20180510056)+2 种基金Foundation of Liaoning Province Education Administration(LQGD2019001)support from the National Science Foundation(DMR1611180 and 1809640)with the program directorssupported by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences,Materials Sciences and Engineering Division under Contract No.DEAC02–05-CH11231。
文摘This work intends to manipulate the internal flow units in Zr_(55)Cu_(30)Ni_(5)Al_(10)bulk-metallic glasses(BMGs)through plasma-assisted hydrogenation to generate a positive microalloying effect on plasticity.Based on the cooperative shear model theory,serration-flow statistics during nanoindentation loading and creep tests during the holding stage were used to analyze the influence of hydrogen on the behavior of flow units in BMGs.Experimental observations showed that the hydrogen in the Zr_(55)Cu_(30)Ni_(5)Al_(10)BMGs caused mechanical softening,plasticity improvement,and structural relaxation.Analysis also showed that the average volume,size,and activation energy of internal flow units in the BMGs all increased as a result of the increase in the hydrogen content.The hydrogenation in the BMGs was found to lead to a prolifera-tion of shear bands,which promoted plasticity.The aggregation of these internal flow units reduced the stress required for plastic deformation through shear bands,ultimately causing softening and structural relaxation.
