We propose a multi-band metamaterial absorber operating at terahertz frequencies. The design, characteriza- tion, and theoretical calculation of the high performance metamaterial absorber are reported. The multi-band ...We propose a multi-band metamaterial absorber operating at terahertz frequencies. The design, characteriza- tion, and theoretical calculation of the high performance metamaterial absorber are reported. The multi-band metamaterial absorber consists of two metallic layers separated by a dielectric spacer. Theoretical and simulated results show that the metamaterial absorber has four distinct absorption points at frequenc/es 0.57 THz, 1.03 THz, 1.44 THz and 1.89 THz, with the absorption rates of 99.9%, 90.3%, 83.0%, 96.1%, respectively. Two single band metamaterial absorbers and a dual band metamaterial absorber on the top layer are designed. Some multi-band absorbers can be designed by virtue of combining some single band absorbers. The multiple-reflection theory is used to explain the absorption mechanism of our investigated structures.展开更多
Particle-fluid system is one of the most popular systems in chemical processes.Owing to complex interface structure and high-velocity turbulence,the momentum and mass transfer exhibit nonlinear characteristics,which p...Particle-fluid system is one of the most popular systems in chemical processes.Owing to complex interface structure and high-velocity turbulence,the momentum and mass transfer exhibit nonlinear characteristics,which pose a great challenge for further study and application.To solve this problem,computational mass transfer(CMT)emerged and has been proved to be effective in deeply exploring the mass transfer behavior of particle-fluid systems.First,this paper reviews recent gas-solid numerical studies of turbulence issues from empirical to theoretical,then discusses interphase mass transfer rate models and the interfacial interaction force.Second,the present study particularly reviews researches on mass transfer process of fixed and fluidized regime by CMT,providing reliable analysis of turbulent anisotropy diffusivity as well as multiscale structure and presenting theoretical instruction for the industrial optimization of mass transfer processes in chemical engineering.展开更多
The experimental research on zero-net-mass-flux jet closed-loop active control was conducted in the wind tunnel.The mu-level method successfully detected burst events of the coherent structures. The streamwise velocit...The experimental research on zero-net-mass-flux jet closed-loop active control was conducted in the wind tunnel.The mu-level method successfully detected burst events of the coherent structures. The streamwise velocity signals in the turbulent boundary layer were measured by HWA. The drag reduction rate of 16.7% is obtained comparable to that of the open-loop control and saves 75% of the input energy at the asynchronous 100 V/160 Hz control case, which reflects the advantages of the closed-loop control. The experimental findings indicate that the intensity increases in the near-wall region.The perturbation of the PZT vibrators on the skewness factor is concentrated in the region y+< 60. The generation of highspeed fluids is depressed and the downward effect of high-speed fluids weakens. The alteration of energy distribution and the discernible impact of modulation between structures of varying scales are observed. The correlation coefficient exhibits a strong positive correlation, which indicates that the large-scale structures produce modulation effect on small-scale ones.The occurrence of burst events is effectively suppressed. The disturbance has the characteristics of stable periodicity,positive and negative symmetry, low intermittency, and high pulsation strength. The conditional phase waveform shows that the fluctuation amplitude increases, indicating amplitude modulation effects on coherent structures.展开更多
L-valve is often used as a non-mechanical valve for the circulation of solids in gas-solids fluidized bed(GSFB)due to its advantages in simple construction and easy control.The information on solids circu-lation rate ...L-valve is often used as a non-mechanical valve for the circulation of solids in gas-solids fluidized bed(GSFB)due to its advantages in simple construction and easy control.The information on solids circu-lation rate as well as the hydrodynamics performance of the CFB with L-valve is of great importance for its better control and design.This paper proposes a Eulerian-Eulerian approach based numerical model integrating the computational fluid dynamics(CFD)with turbulent model,the kinetic theory of granular flow(KTGF)and the drag model,thus the solids circulation rate and the local phase velocity as well as solids volume fraction can be predicted simultaneously.With this model,the hydrodynamics perfor-mance of the full loop GSCFB with a L-valve is analyzed in detail.It is found that the drag model affects the simulation significantly and the(energy minimization multiscale)EMMS method shows good per-formance in the full-loop simulation of GSCFB.展开更多
Arsenic（As） is one of the most toxic contaminants found in the environment. Development of novel detection methods for As species in water with the potential for field use has been an urgent need in recent years. In...Arsenic（As） is one of the most toxic contaminants found in the environment. Development of novel detection methods for As species in water with the potential for field use has been an urgent need in recent years. In past decades, surface-enhanced Raman scattering（SERS）has gained a reputation as one of the most sensitive spectroscopic methods for chemical and biomolecular sensing. The SERS technique has emerged as an extremely promising solution for in-situ detection of arsenic species in the field, particularly when coupled with portable/handheld Raman spectrometers. In this article, the recent advances in SERS analysis of arsenic species in water media are reviewed, and the potential of this technique for fast screening and field testing of arsenic-contaminated environmental water samples is discussed. The problems that remain in the field are also discussed and an outlook for the future is featured at the end of the article.展开更多
In order to manipulate the large-scale coherent structures in the wall-bounded turbulence and reduce the skin-friction,an active-control experimental investigation is performed by using the synchronous and asynchronou...In order to manipulate the large-scale coherent structures in the wall-bounded turbulence and reduce the skin-friction,an active-control experimental investigation is performed by using the synchronous and asynchronous vibrations of double piezoelectric vibrators embedded spanwisely on a smooth flat plate surface.A TSI-IFA300 hot-wire anemometer and a TSI-1621 A-Tl.5 hot-wire probe are used to measure the time series of the instantaneous velocity at different locations.The influences of the vibrations on the wall-bounded turbulence are compared in a multi-scale point of view.A disturbance Reynolds Number Red=pd2 f/μis introduced to represent the disturbance.A probability density functions(PDFs)of the multi-scale components of the turbulence velocity and the multi-scale conditional phase-averaged waveform are studied in detail using the wavelet transform.The results show that the maximum drag reduction rate 18.54%is obtained at 100 V/160 Hz and Red=0.54 in the asynchronous vibration mode.The disturbances generated by the vibrators have a significant influence on the sweep events of the burst.The asynchronous vibration model is more effective than the synchronous vibration one.A possible physical mechanism is suggested to explain why the disturbance frequency of 160 Hz leads to an optimal parameter set for the drag reduction.展开更多
The gelation behaviours of low molecular weight gelators 1,3：2,5：4.6-tris（3,4-dichlorobenzylidene）-Dmannitol（G1） and 2,4-（3.4-dichlorobenzylidene）-N-（3-aminopropyl）-D-gluconamide（G2） in 34 solvents have be...The gelation behaviours of low molecular weight gelators 1,3：2,5：4.6-tris（3,4-dichlorobenzylidene）-Dmannitol（G1） and 2,4-（3.4-dichlorobenzylidene）-N-（3-aminopropyl）-D-gluconamide（G2） in 34 solvents have been studied.We found that sample dissolved at low concentrations may become a gel or precipitate at higher concentrations.The Hansen solubility parameters（HSPs） and a Teas plot were employed to correlate the gelation behaviours with solvent properties,but with no success if the concentration of the tests was not maintained constant.Instead,on the basis of the gelation results obtained for the G1 and G2 in single solvents,we studied the gelation behaviours of G1 and G2 in23 solvent mixtures and found that the tendency of a gelator to form a gel in mixed solvents is strongly correlated with its gelation behaviours in good solvents.If the gelation occurs in a good solvent at higher concentrations,it will take place as well in a mixed solvent（the good solvent plus a poor solvent） at a certain volume ratio.In contrast,if the gelator forms a precipitate in a good solvent at higher concentrations,no gelation is to be observed in the mixed solvents.A gelation rule for mixed solvents is thus proposed,which may facilitate decision making with regard to solvent selection for gel formation in the solvent mixtures in practical applications.展开更多
Nickel-iron layered double hydroxides(NiFe LDHs) have been identified as one of the best promising electrocatalysts-candidates for oxygen evolution reaction(OER). However, the catalytic activity effected by interlayer...Nickel-iron layered double hydroxides(NiFe LDHs) have been identified as one of the best promising electrocatalysts-candidates for oxygen evolution reaction(OER). However, the catalytic activity effected by interlayer water molecules is ignored and rarely reported. Herein, Ni(OH)_2, NiFe LDHs vertically aligned Ni foam are designed for OER. As a contrast, the corresponding electrocatalysts with the removal of the interlayer water molecules(Ni(OH)_2-AT, NiFe LDHs-AT) are developed to probe into the influence of the interlayer water molecules towards OER. As expected, NiFe LDH nanoplates exhibit excellent catalytic performance and durability for water electrolysis in alkaline conditions with lower overpotential and smaller Tafel slope compared to those of NiFe LDHs-AT, which are influenced mainly by stability of crystal structure due to the existence of interlayer water molecules. The discovery opens up a similar pathway by controlling the amount of water molecules to boost catalytic performance for studying other electrocatalysts with heteroatom dopant.展开更多
An asymmetric quantum well (AQW) is designed to emit a terahertz (THz) wave by using difference frequency generation (DFG) with the structure of GaAs/Al_(0.2)Ga_(0.8)As/Al_(0.5) Ga_(0.5)As under a doubly resonant cond...An asymmetric quantum well (AQW) is designed to emit a terahertz (THz) wave by using difference frequency generation (DFG) with the structure of GaAs/Al_(0.2)Ga_(0.8)As/Al_(0.5) Ga_(0.5)As under a doubly resonant condition.It is found that the second-order nonlinear susceptibility χ^((2)) varies with the two pump wavelengths,and it can reach the peak value of 1.61 μm/V when the wavelengths are given as λ_(p1) =9.756 μm and λ_(p2) =10.96 μm,respectively.The numerical results show that the refractive index of one pump wave in the AQW is concerned with not only its own wavelength but also the other wavelength.Phase-matching inside the AQW can be obtained through the tuning of the two pump wavelengths.展开更多
A novel series of calix[4]azacrown derivatives with the reaction between calix[4]azacrown and the different fluorophore derivatives,which may be useful fluorescent receptors,have been synthesized and structurally char...A novel series of calix[4]azacrown derivatives with the reaction between calix[4]azacrown and the different fluorophore derivatives,which may be useful fluorescent receptors,have been synthesized and structurally characterized by IR,~1H NMR,^（13）C NMR and MS.From their analysis data,it was found those compounds adopted a cone conformation.展开更多
A theoretical model of cascaded terahertz(THz) difference-frequency generation is established based on one-dimensional coupled-wave equations.The relationships between sphalerite crystals' wave vector mismatches a...A theoretical model of cascaded terahertz(THz) difference-frequency generation is established based on one-dimensional coupled-wave equations.The relationships between sphalerite crystals' wave vector mismatches and difference-frequency pump waves are analyzed.To produce terahertz wave with the frequency of 1.5 THz,80-order cascaded difference-frequency is applied.By introducing crystal absorption,we calculate the optimum crystal length and pump frequency under actual circumstances.It is found that Stokes waves dominate the terahertz waves output in cascaded progress,and cascaded difference-frequency can increase the photon conversion efficiency obviously.展开更多
We propose a design and numerical study of an optically blueshift and redshift switchable metamaterial(MM)absorber in the terahertz regime.The MM absorber comprises a periodic array of metallic split-ring resonators(S...We propose a design and numerical study of an optically blueshift and redshift switchable metamaterial(MM)absorber in the terahertz regime.The MM absorber comprises a periodic array of metallic split-ring resonators(SRRs)with semiconductor silicon embedded in the gaps of MM resonators.The absorptive frequencies of the MM can be shifted by applying an external pump power.The simulation results show that,for photoconductivity of silicon ranging between 1 S/m and 4000 S/m,the resonance peak of the absorption spectra shifts to higher frequencies,from 0.67 THz to 1.63 THz,with a resonance tuning range of 59%.As the conductivity of silicon increases,the resonance frequencies of the MM absorber are continuously tuned from 1.60 THz to 1.16 THz,a redshift tuning range of 28%.As the conductivity increases above 30000 S/m,the resonance frequencies tend to be stable while the absorption peak has a merely tiny variation.The optical-tuned absorber has potential applications as a terahertz modulator or switch.展开更多
A yttria promoted nickel nanowire catalyst was prepared by a hard templating method, and characterized by transmission electron microscopy (TEM) and N2 physical adsorption. The catalytic properties of the yttria promo...A yttria promoted nickel nanowire catalyst was prepared by a hard templating method, and characterized by transmission electron microscopy (TEM) and N2 physical adsorption. The catalytic properties of the yttria promoted nanowire catalyst in the partial oxidation of methane to syngas were compared with a metallic Ni catalyst which was prepared with nickel sponge. The characterization results showed that the yttria promoted nickel nanowire catalyst had high specific surface area and there was more NiO phase in the nickel nanowire catalyst than in the metallic Ni catalyst. The reaction results showed that the yttria promoted nickel nanowire catalyst had high CH4 conversion and selectivities to H2 and CO.展开更多
文摘We propose a multi-band metamaterial absorber operating at terahertz frequencies. The design, characteriza- tion, and theoretical calculation of the high performance metamaterial absorber are reported. The multi-band metamaterial absorber consists of two metallic layers separated by a dielectric spacer. Theoretical and simulated results show that the metamaterial absorber has four distinct absorption points at frequenc/es 0.57 THz, 1.03 THz, 1.44 THz and 1.89 THz, with the absorption rates of 99.9%, 90.3%, 83.0%, 96.1%, respectively. Two single band metamaterial absorbers and a dual band metamaterial absorber on the top layer are designed. Some multi-band absorbers can be designed by virtue of combining some single band absorbers. The multiple-reflection theory is used to explain the absorption mechanism of our investigated structures.
基金the NSFC Project(grant No.22078230)the State Key Laboratory of Heavy Oil Processing(grant No.SKLHOP202202008)the National Key Researchh and Development Program ofC hina(granNt o.2018YFE0111100).
文摘Particle-fluid system is one of the most popular systems in chemical processes.Owing to complex interface structure and high-velocity turbulence,the momentum and mass transfer exhibit nonlinear characteristics,which pose a great challenge for further study and application.To solve this problem,computational mass transfer(CMT)emerged and has been proved to be effective in deeply exploring the mass transfer behavior of particle-fluid systems.First,this paper reviews recent gas-solid numerical studies of turbulence issues from empirical to theoretical,then discusses interphase mass transfer rate models and the interfacial interaction force.Second,the present study particularly reviews researches on mass transfer process of fixed and fluidized regime by CMT,providing reliable analysis of turbulent anisotropy diffusivity as well as multiscale structure and presenting theoretical instruction for the industrial optimization of mass transfer processes in chemical engineering.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12202309,1233000165,12172242,and 12272265)Science and Technology Program of Gansu Province of China(Grant No.22JR5RA304)Tianjin Research Innovation for Postgraduate Students(Grant No.22KJ049)。
文摘The experimental research on zero-net-mass-flux jet closed-loop active control was conducted in the wind tunnel.The mu-level method successfully detected burst events of the coherent structures. The streamwise velocity signals in the turbulent boundary layer were measured by HWA. The drag reduction rate of 16.7% is obtained comparable to that of the open-loop control and saves 75% of the input energy at the asynchronous 100 V/160 Hz control case, which reflects the advantages of the closed-loop control. The experimental findings indicate that the intensity increases in the near-wall region.The perturbation of the PZT vibrators on the skewness factor is concentrated in the region y+< 60. The generation of highspeed fluids is depressed and the downward effect of high-speed fluids weakens. The alteration of energy distribution and the discernible impact of modulation between structures of varying scales are observed. The correlation coefficient exhibits a strong positive correlation, which indicates that the large-scale structures produce modulation effect on small-scale ones.The occurrence of burst events is effectively suppressed. The disturbance has the characteristics of stable periodicity,positive and negative symmetry, low intermittency, and high pulsation strength. The conditional phase waveform shows that the fluctuation amplitude increases, indicating amplitude modulation effects on coherent structures.
基金support by the National Key Research and Development Program of China(grant No.2018YFE0111100)the National Nature Science Foundation of China(grant No.22078230)the Open Foundation of State Key Laboratory of Chemical Engineering(grant No.SKL-ChE-21B07).
文摘L-valve is often used as a non-mechanical valve for the circulation of solids in gas-solids fluidized bed(GSFB)due to its advantages in simple construction and easy control.The information on solids circu-lation rate as well as the hydrodynamics performance of the CFB with L-valve is of great importance for its better control and design.This paper proposes a Eulerian-Eulerian approach based numerical model integrating the computational fluid dynamics(CFD)with turbulent model,the kinetic theory of granular flow(KTGF)and the drag model,thus the solids circulation rate and the local phase velocity as well as solids volume fraction can be predicted simultaneously.With this model,the hydrodynamics perfor-mance of the full loop GSCFB with a L-valve is analyzed in detail.It is found that the drag model affects the simulation significantly and the(energy minimization multiscale)EMMS method shows good per-formance in the full-loop simulation of GSCFB.
基金supported by the National Natural Science Foundation of China (Grant Nos.12202310,12202309,1233201712202309,and 12332017)Chinesisch-Deutsche Zentrum für Wissenschaftsförderung (Grant No.GZ1575)China Postdoctoral Science Foundation (Grant No.2022M712357).
文摘Arsenic（As） is one of the most toxic contaminants found in the environment. Development of novel detection methods for As species in water with the potential for field use has been an urgent need in recent years. In past decades, surface-enhanced Raman scattering（SERS）has gained a reputation as one of the most sensitive spectroscopic methods for chemical and biomolecular sensing. The SERS technique has emerged as an extremely promising solution for in-situ detection of arsenic species in the field, particularly when coupled with portable/handheld Raman spectrometers. In this article, the recent advances in SERS analysis of arsenic species in water media are reviewed, and the potential of this technique for fast screening and field testing of arsenic-contaminated environmental water samples is discussed. The problems that remain in the field are also discussed and an outlook for the future is featured at the end of the article.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11732010,11972251,11872272,11902218 and 11802195).
文摘In order to manipulate the large-scale coherent structures in the wall-bounded turbulence and reduce the skin-friction,an active-control experimental investigation is performed by using the synchronous and asynchronous vibrations of double piezoelectric vibrators embedded spanwisely on a smooth flat plate surface.A TSI-IFA300 hot-wire anemometer and a TSI-1621 A-Tl.5 hot-wire probe are used to measure the time series of the instantaneous velocity at different locations.The influences of the vibrations on the wall-bounded turbulence are compared in a multi-scale point of view.A disturbance Reynolds Number Red=pd2 f/μis introduced to represent the disturbance.A probability density functions(PDFs)of the multi-scale components of the turbulence velocity and the multi-scale conditional phase-averaged waveform are studied in detail using the wavelet transform.The results show that the maximum drag reduction rate 18.54%is obtained at 100 V/160 Hz and Red=0.54 in the asynchronous vibration mode.The disturbances generated by the vibrators have a significant influence on the sweep events of the burst.The asynchronous vibration model is more effective than the synchronous vibration one.A possible physical mechanism is suggested to explain why the disturbance frequency of 160 Hz leads to an optimal parameter set for the drag reduction.
基金the financial support of the National Natural Science Foundation of China(Nos.21276188,21476164)Tianjin Science and Technology Innovation Platform Program(No.14TXGCCX00017)
文摘The gelation behaviours of low molecular weight gelators 1,3：2,5：4.6-tris（3,4-dichlorobenzylidene）-Dmannitol（G1） and 2,4-（3.4-dichlorobenzylidene）-N-（3-aminopropyl）-D-gluconamide（G2） in 34 solvents have been studied.We found that sample dissolved at low concentrations may become a gel or precipitate at higher concentrations.The Hansen solubility parameters（HSPs） and a Teas plot were employed to correlate the gelation behaviours with solvent properties,but with no success if the concentration of the tests was not maintained constant.Instead,on the basis of the gelation results obtained for the G1 and G2 in single solvents,we studied the gelation behaviours of G1 and G2 in23 solvent mixtures and found that the tendency of a gelator to form a gel in mixed solvents is strongly correlated with its gelation behaviours in good solvents.If the gelation occurs in a good solvent at higher concentrations,it will take place as well in a mixed solvent（the good solvent plus a poor solvent） at a certain volume ratio.In contrast,if the gelator forms a precipitate in a good solvent at higher concentrations,no gelation is to be observed in the mixed solvents.A gelation rule for mixed solvents is thus proposed,which may facilitate decision making with regard to solvent selection for gel formation in the solvent mixtures in practical applications.
基金financially supported by the National Natural Science Foundation of China (51622102, 51571124, 21421001)MOST (2017YFA0206702)+3 种基金the 111 Project (B12015)the Natural Science Foundation of Tianjin (16PTSYJC00030)the Fundamental Research Funds for the Central Universitiesthe Tianjin Colle ge Students Innovation and Entrepreneurship Training Project (201814038024)。
文摘Nickel-iron layered double hydroxides(NiFe LDHs) have been identified as one of the best promising electrocatalysts-candidates for oxygen evolution reaction(OER). However, the catalytic activity effected by interlayer water molecules is ignored and rarely reported. Herein, Ni(OH)_2, NiFe LDHs vertically aligned Ni foam are designed for OER. As a contrast, the corresponding electrocatalysts with the removal of the interlayer water molecules(Ni(OH)_2-AT, NiFe LDHs-AT) are developed to probe into the influence of the interlayer water molecules towards OER. As expected, NiFe LDH nanoplates exhibit excellent catalytic performance and durability for water electrolysis in alkaline conditions with lower overpotential and smaller Tafel slope compared to those of NiFe LDHs-AT, which are influenced mainly by stability of crystal structure due to the existence of interlayer water molecules. The discovery opens up a similar pathway by controlling the amount of water molecules to boost catalytic performance for studying other electrocatalysts with heteroatom dopant.
基金Supported by National Natural Science Foundation of China under Grant Nos 60801017,61172010,61101058,and 61107086the Science and Technology Committee of Tianjin under Grant No 11JCYBJC01100.
文摘An asymmetric quantum well (AQW) is designed to emit a terahertz (THz) wave by using difference frequency generation (DFG) with the structure of GaAs/Al_(0.2)Ga_(0.8)As/Al_(0.5) Ga_(0.5)As under a doubly resonant condition.It is found that the second-order nonlinear susceptibility χ^((2)) varies with the two pump wavelengths,and it can reach the peak value of 1.61 μm/V when the wavelengths are given as λ_(p1) =9.756 μm and λ_(p2) =10.96 μm,respectively.The numerical results show that the refractive index of one pump wave in the AQW is concerned with not only its own wavelength but also the other wavelength.Phase-matching inside the AQW can be obtained through the tuning of the two pump wavelengths.
基金the National High Technology Research and Development Program 863(No. 2008AA03A315)The Research Fund for the Doctoral Program of High Education(No.20060056017).
文摘A novel series of calix[4]azacrown derivatives with the reaction between calix[4]azacrown and the different fluorophore derivatives,which may be useful fluorescent receptors,have been synthesized and structurally characterized by IR,~1H NMR,^（13）C NMR and MS.From their analysis data,it was found those compounds adopted a cone conformation.
基金supported by National "863" Project (No.2011AA030208)
文摘A theoretical model of cascaded terahertz(THz) difference-frequency generation is established based on one-dimensional coupled-wave equations.The relationships between sphalerite crystals' wave vector mismatches and difference-frequency pump waves are analyzed.To produce terahertz wave with the frequency of 1.5 THz,80-order cascaded difference-frequency is applied.By introducing crystal absorption,we calculate the optimum crystal length and pump frequency under actual circumstances.It is found that Stokes waves dominate the terahertz waves output in cascaded progress,and cascaded difference-frequency can increase the photon conversion efficiency obviously.
基金Supported by the National Key Research and Development Program of China under Grant No.2017YFA0700202
文摘We propose a design and numerical study of an optically blueshift and redshift switchable metamaterial(MM)absorber in the terahertz regime.The MM absorber comprises a periodic array of metallic split-ring resonators(SRRs)with semiconductor silicon embedded in the gaps of MM resonators.The absorptive frequencies of the MM can be shifted by applying an external pump power.The simulation results show that,for photoconductivity of silicon ranging between 1 S/m and 4000 S/m,the resonance peak of the absorption spectra shifts to higher frequencies,from 0.67 THz to 1.63 THz,with a resonance tuning range of 59%.As the conductivity of silicon increases,the resonance frequencies of the MM absorber are continuously tuned from 1.60 THz to 1.16 THz,a redshift tuning range of 28%.As the conductivity increases above 30000 S/m,the resonance frequencies tend to be stable while the absorption peak has a merely tiny variation.The optical-tuned absorber has potential applications as a terahertz modulator or switch.
文摘A yttria promoted nickel nanowire catalyst was prepared by a hard templating method, and characterized by transmission electron microscopy (TEM) and N2 physical adsorption. The catalytic properties of the yttria promoted nanowire catalyst in the partial oxidation of methane to syngas were compared with a metallic Ni catalyst which was prepared with nickel sponge. The characterization results showed that the yttria promoted nickel nanowire catalyst had high specific surface area and there was more NiO phase in the nickel nanowire catalyst than in the metallic Ni catalyst. The reaction results showed that the yttria promoted nickel nanowire catalyst had high CH4 conversion and selectivities to H2 and CO.
