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Abstract The electrochemical reduction of nitrates (NO3−) enables a pathway for the carbon neutral synthesis of ammonia (NH3), via the nitrate reduction reaction (NO3RR), which has been demonstrated at high selectivity. However, to make NH3synthesis cost‐competitive with current technologies, high NH3partial current densities (jNH3) must be achieved to reduce the levelized cost of NH3. Here, the high NO3RR activity of Fe‐based materials is leveraged to synthesize a novel active particle‐active support system with Fe2O3nanoparticles supported on atomically dispersed Fe–N–C. The optimized 3×Fe2O3/Fe–N–C catalyst demonstrates an ultrahigh NO3RR activity, reaching a maximum jNH3of 1.95 A cm−2at a Faradaic efficiency (FE) for NH3of 100% and an NH3yield rate over 9 mmol hr−1cm−2. Operando XANES and post‐mortem XPS reveal the importance of a pre‐reduction activation step, reducing the surface Fe2O3(Fe3+) to highly active Fe0sites, which are maintained during electrolysis. Durability studies demonstrate the robustness of both the Fe2O3particles and Fe–Nxsites at highly cathodic potentials, maintaining a current of −1.3 A cm−2over 24 hours. This work exhibits an effective and durable active particle‐active support system enhancing the performance of the NO3RR, enabling industrially relevant current densities and near 100% selectivity.
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Absolute spatially and time‐resolved O, O 3 , and air densities in the effluent of a modulated RF‐driven atmospheric pressure plasma jet obtained by molecular beam mass spectrometry
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 ClO−production in saline by the same plasma jet.
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- Award ID(s):
- 1703439
- PAR ID:
- 10126909
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Plasma Processes and Polymers
- Volume:
- 17
- Issue:
- 6
- ISSN:
- 1612-8850
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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