skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


This content will become publicly available on January 28, 2026

Title: Ammonia decomposition over low-loading ruthenium catalyst achieved through “adiabatic” plasma reactor
The heat effect of nonthermal plasma significantly enhanced the synergy between the plasma and the catalytically active sites. Consequently, nearly 100% NH3decomposition was achieved over the low-loading Ru/Al2O3catalyst under adiabatic conditions.  more » « less
Award ID(s):
2239408
PAR ID:
10573294
Author(s) / Creator(s):
; ; ; ; ; ; ; ;
Publisher / Repository:
RSC
Date Published:
Journal Name:
Reaction Chemistry & Engineering
Volume:
10
Issue:
2
ISSN:
2058-9883
Page Range / eLocation ID:
320 to 331
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract The Quantemol database (QDB) provides cross sections and rates of processes important for plasma models; heavy particle collisions (chemical reactions) and electron collision processes are considered. The current version of QDB has data on 28 917 processes between 2485 distinct species plus data for surface processes. These data are available via a web interface or can be delivered directly to plasma models using an application program interface; data are available in formats suitable for direct input into a variety of popular plasma modeling codes including HPEM, COMSOL, ChemKIN, CFD-ACE+, and VisGlow. QDB provides ready assembled plasma chemistries plus the ability to build bespoke chemistries. The database also provides a Boltzmann solver for electron dynamics and a zero-dimensional model. Thesedevelopments, use cases involving O2, Ar/NF3, Ar/NF3/O2, and He/H2O/O2chemistries, and plans for the future are presented. 
    more » « less
  2. Abstract In this paper, we report a molecular beam mass spectrometer study of a time‐modulated radiofrequency (RF)‐driven atmospheric pressure plasma jet in Ar + 1% O2. Time‐resolved measurements of the absolute density of O3during the RF modulation period revealed a temporal increase of O3densities at the start and end of the power modulation. This increase correlates with the increase in O2due to plasma‐induced transient vortices in the gas jet. Pseudo‐one‐dimensional plug flow modeling of the axial species densities as a function of distance match well with the experimentally recorded trends. The obtained results were used to assess the importance of the O flux in previously reported ClOproduction in saline by the same plasma jet. 
    more » « less
  3. Membrane permeabilities to CO2and HCO3constrain the function of CO2concentrating mechanisms that algae use to supply inorganic carbon for photosynthesis. In diatoms and green algae, plasma membranes are moderately to highly permeable to CO2but effectively impermeable to HCO3. Here, CO2and HCO3membrane permeabilities were measured using an18O‐exchange technique on two species of haptophyte algae,Emiliania huxleyiandCalcidiscus leptoporus, which showed that the plasma membranes of these species are also highly permeable to CO2(0.006–0.02 cm · s−1) but minimally permeable to HCO3. Increased temperature and CO2generally increased CO2membrane permeabilities in both species, possibly due to changes in lipid composition or CO2channel proteins. Changes in CO2membrane permeabilities showed no association with the density of calcium carbonate coccoliths surrounding the cell, which could potentially impede passage of compounds. Haptophyte plasma‐membrane permeabilities to CO2were somewhat lower than those of diatoms but generally higher than membrane permeabilities of green algae. One caveat of these measurements is that the model used to interpret18O‐exchange data assumes that carbonic anhydrase, which catalyzes18O‐exchange, is homogeneously distributed in the cell. The implications of this assumption were tested using a two‐compartment model with an inhomogeneous distribution of carbonic anhydrase to simulate18O‐exchange data and then inferring plasma‐membrane CO2permeabilities from the simulated data. This analysis showed that the inferred plasma‐membrane CO2permeabilities are minimal estimates but should be quite accurate under most conditions. 
    more » « less
  4. Non-equilibrium plasma has been found to have a synergistic effect on catalytic synthesis of NH3
    more » « less
  5. This paper demonstrates a simultaneous Thomson scattering and rotational Raman scattering spectroscopy in a weakly ionized plasma in air. Thomson scattering was collected in the forward scattering direction, in order to compress the relative spectra width of Thomson scattering from the plasma. Simultaneous measurements of rotational Raman scattering were obtained in the same direction, which was not affected by the collection angles. The measurements thus yielded electron temperature (Te) and electron number density (ne) as well as gas temperature in a weakly ionized atmospheric pressure plasma. The separation of rotational Raman scattering and Thomson scattering occurred when the scattering angle decreased to 20 degrees in the plasma, where the air temperature was found to be 150 ± 25 °C, and electron temperature of the plasma was 0.587 ± 0.087 eV, and electron number density was (1.608 ± 0.416) × 1021 m-3. The technique could be used for various plasma and combustion diagnostics in realistic engineering environments. 
    more » « less