Metrology of non-thermal capacitively coupled N2–Ar mixture plasma

Rehman, Najeeb Ur; Anjum, Zakia; Masood, Anum; Farooq, Muhammad; Ahmad, Ishaq; Zakaullah, M.

doi:10.1016/j.optcom.2013.01.004

Cited by 21 publications

(7 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A typical spectrum is shown in Figure S5 where N 2 alone was flowed onto 1.10 g of Cu wool and the spectrum was observed from the lower end of the quartz reactor. A very intense N 2 * band (C 3 Π u → B 3 Π g , a second positive band from an activated neutral nitrogen molecule) was observed with weak bands for N 2 * (B 3 Π g → A 3 Σ u , a first positive band), N 2 * (C″ 5 Σ u → A′ 5 Σ g , a Herman infrared band), N 2 + (B 2 Σ u + → X 2 Π g + , a first negative band), and NO (A 2 Σ 3+ → X 2 Π, a γ band) . The appearance of NO γ bands has widely been reported to be due to a trace level of oxygen impurity .…”

Section: Results and Discussionmentioning

confidence: 99%

“…A very intense N 2 * band (C 3 Π u → B 3 Π g , a second positive band from an activated neutral nitrogen molecule) was observed with weak bands for N 2 * (B 3 Π g → A 3 Σ u , a first positive band), N 2 * (C″ 5 Σ u → A′ 5 Σ g , a Herman infrared band), N 2 + (B 2 Σ u + → X 2 Π g + , a first negative band), and NO (A 2 Σ 3+ → X 2 Π, a γ band) . The appearance of NO γ bands has widely been reported to be due to a trace level of oxygen impurity . In the current experiment, the intensity of the N 2 + emission bands was far lower than that of N 2 *.…”

Section: Results and Discussionmentioning

confidence: 99%

“…Electro-catalysis using Ag–Pd alloys or Ru/perovskite oxides − was also reported to be active for the ammonia formation, although the production rates were far lower than those of the Haber–Bosch process. In the field of plasma-assisted catalysis, a nonthermal atmospheric plasma was applied to synthesize ammonia, − and catalyst-loaded ceramic membranes or bimetallic oxide systems were used to obtain yields of approximately 2%. However, these have disadvantages, including slow production rates, due to the slow flowing velocity of the reactant gases .…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Ammonia Synthesis on Wool-Like Au, Pt, Pd, Ag, or Cu Electrode Catalysts in Nonthermal Atmospheric-Pressure Plasma of N₂ and H₂

et al. 2017

View full text Add to dashboard Cite

Developing an ammonia synthesis process from N2 and H2 is of interest in the catalysis and hydrogen research community. Wool-like metal electrodes used to produce nonthermal plasma were determined to serve as efficient catalysts for ammonia synthesis under atmospheric pressure without heating. The catalytic activity of Pt, Pd, Ag, Cu, and Ni wools increased as the experiment was repeated, while that of Au, Fe, Mo, Ti, W, and Al was almost constant. The activity change was mainly due to migration of metals from the electrode to the inner wall of a silica reactor or increases in surface areas of metal catalysts. The order of the activity at each initial experiment was Au > Pt > Pd > Ag > Cu > Fe > Mo > Ni > W > Ti > Al. DFT calculations using Gaussian 09 and CASTEP were applied for energy changes in a reaction M3 + 1/2 N2 → M3N and in adsorption of a nitrogen atom on metal surface, in which M3 was a virtual minimum unit of the metal surface. The reactions were assumed to be an essential step in the ammonia production after plasma-activation of N2. The resulting values correlated with the respective initial catalytic activity, indicating that a more unstable M3N surface intermediate produced higher catalytic activity. Emission spectra in the plasma process using various electrodes were measured and showed that the efficiency of electrodes for plasma activation of nitrogen molecules was almost independent of the metals, while the reactivity of the activated species to form ammonia depended greatly on the metal used. The N2/H2 ratio dependence and formation/decomposition rate constants of ammonia were finally determined on Au and Cu, which were different from those for the conventional Haber–Bosch process. The decomposition of produced ammonia was suggested to proceed in a plasma-irradiated gas phase.

show abstract

Section: Results and Discussionmentioning

confidence: 99%

Section: Results and Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Ammonia Synthesis on Wool-Like Au, Pt, Pd, Ag, or Cu Electrode Catalysts in Nonthermal Atmospheric-Pressure Plasma of N₂ and H₂

et al. 2017

View full text Add to dashboard Cite

show abstract

“…where X 1i is the rate coefficient describing electron impact excitation from the ground level 1 to level i, [28][29][30]32] ∑ i> j A i j is the accumulative transition probability for spontaneous emission from the higher level i to all the other lower levels j, and N e , N 1 , N i are the electron density, ground level population density, and excited state population density, respectively.…”

Section: Calculated Methods Of Electron Temperaturementioning

confidence: 99%

“…Note, we suppose the plasma is optically thin. Furthermore, X 1i can be expressed as a simple expression related to T e [28][29][30][31][32]…”

Section: Calculated Methods Of Electron Temperaturementioning

confidence: 99%

Discharge characteristic of very high frequency capacitively coupled argon plasma*

Yin¹,

Wang²,

Gao³

et al. 2021

Chinese Phys. B

View full text Add to dashboard Cite

The discharge characteristics of capacitively coupled argon plasmas driven by very high frequency discharge are studied. The mean electron temperature and electron density are calculated by using the Ar spectral lines at different values of power (20 W–70 W) and four different frequencies (13.56 MHz, 40.68 MHz, 94.92 MHz, and 100 MHz). The mean electron temperature decreases with the increase of power at a fixed frequency. The mean electron temperature varies non-linearly with frequency increasing at constant power. At 40.68 MHz, the mean electron temperature is the largest. The electron density increases with the increase of power at a fixed frequency. In the cases of driving frequencies of 94.92 MHz and 100 MHz, the obtained electron temperatures are almost the same, so are the electron densities. Particle-in-cell/Monte-Carlo collision (PIC/MCC) method developed within the Vsim 8.0 simulation package is used to simulate the electron density, the potential distribution, and the electron energy probability function (EEPF) under the experimental condition. The sheath width increases with the power increasing. The EEPF of 13.56 MHz and 40.68 MHz are both bi-Maxwellian with a large population of low-energy electrons. The EEPF of 94.92 MHz and 100 MHz are almost the same and both are nearly Maxwellian.

show abstract

Influence of Nitrogen Seeding on the Electron and Ion Behaviors in Helicon Wave Excited Argon Plasma

Huang

et al. 2023

Plasma Chem Plasma Process

View full text Add to dashboard Cite

Metrology of non-thermal capacitively coupled N2–Ar mixture plasma

Cited by 21 publications

References 15 publications

Ammonia Synthesis on Wool-Like Au, Pt, Pd, Ag, or Cu Electrode Catalysts in Nonthermal Atmospheric-Pressure Plasma of N₂ and H₂

Ammonia Synthesis on Wool-Like Au, Pt, Pd, Ag, or Cu Electrode Catalysts in Nonthermal Atmospheric-Pressure Plasma of N₂ and H₂

Discharge characteristic of very high frequency capacitively coupled argon plasma*

Influence of Nitrogen Seeding on the Electron and Ion Behaviors in Helicon Wave Excited Argon Plasma

Contact Info

Product

Resources

About

Metrology of non-thermal capacitively coupled N2–Ar mixture plasma

Cited by 21 publications

References 15 publications

Ammonia Synthesis on Wool-Like Au, Pt, Pd, Ag, or Cu Electrode Catalysts in Nonthermal Atmospheric-Pressure Plasma of N2 and H2

Ammonia Synthesis on Wool-Like Au, Pt, Pd, Ag, or Cu Electrode Catalysts in Nonthermal Atmospheric-Pressure Plasma of N2 and H2

Discharge characteristic of very high frequency capacitively coupled argon plasma*

Influence of Nitrogen Seeding on the Electron and Ion Behaviors in Helicon Wave Excited Argon Plasma

Contact Info

Product

Resources

About

Ammonia Synthesis on Wool-Like Au, Pt, Pd, Ag, or Cu Electrode Catalysts in Nonthermal Atmospheric-Pressure Plasma of N₂ and H₂

Ammonia Synthesis on Wool-Like Au, Pt, Pd, Ag, or Cu Electrode Catalysts in Nonthermal Atmospheric-Pressure Plasma of N₂ and H₂