Electrochemically Stabilized Iron Foam Enables Selective and Durable Nitrate-to-Ammonia Conversion at Industrial Current Densities
- 1University of Bern
Abstract
We report the synthesis of Fe foams by dynamic hydrogen bubble template (DHBT)-assisted electrodeposition and their electrocatalytic performance for the selective reduction of nitrate to ammonia, a strategy that mitigates nitrate pollution while providing a decentralized route for ammonia production. Fe-foam_90s@Ti achieves a Faradaic efficiency of up to 97% and a partial current density for ammonia formation approaching -1 A cm -2 without externally imposed convection. Operando Raman spectroscopy tracked the potential-dependent reduction of surface Fe oxides and, together with identical-location scanning electron microscopy (IL-SEM), supported the assignment of metallic Fe as the catalytically active state for selective ammonia formation. Potential-dependent ICP-MS and ion chromatography analyses identified an operating window with minimal Fe dissolution, in which the corrosion-prone catalyst can be electrochemically stabilized through cathodic protection. The catalyst was further implemented in a laboratory-scale flow-cell electrolyzer under galvanostatic conditions, demonstrating its compatibility with continuous-flow operation. Together, these results establish DHBT-derived Fe foams as promising electrocatalysts for high-rate ammonia electrosynthesis and support their further evaluation in scaled flow-cell systems.
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BibTeX
@misc{syamaladevi2026electrochemically,
title = {{Electrochemically Stabilized Iron Foam Enables Selective and Durable Nitrate-to-Ammonia Conversion at Industrial Current Densities}},
author = {Nandu Ashtaman Pillai Syamaladevi and Abhijit Dutta and Peter Broekmann},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv-2025-g53rc/v3},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv-2025-g53rc/v3},
note = {CC BY},
}
RIS
TY - UNPB
TI - Electrochemically Stabilized Iron Foam Enables Selective and Durable Nitrate-to-Ammonia Conversion at Industrial Current Densities
AU - Nandu Ashtaman Pillai Syamaladevi
AU - Abhijit Dutta
AU - Peter Broekmann
PY - 2026
DA - 2026/10/04
PB - ChemRxiv
DO - 10.26434/chemrxiv-2025-g53rc/v3
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv-2025-g53rc/v3
AB - We report the synthesis of Fe foams by dynamic hydrogen bubble template (DHBT)-assisted electrodeposition and their electrocatalytic performance for the selective reduction of nitrate to ammonia, a strategy that mitigates nitrate pollution while providing a decentralized route for ammonia production. Fe-foam_90s@Ti achieves a Faradaic efficiency of up to 97% and a partial current density for ammonia formation approaching -1 A cm -2 without externally imposed convection. Operando Raman spectroscopy tracked the potential-dependent reduction of surface Fe oxides and, together with identical-location scanning electron microscopy (IL-SEM), supported the assignment of metallic Fe as the catalytically active state for selective ammonia formation. Potential-dependent ICP-MS and ion chromatography analyses identified an operating window with minimal Fe dissolution, in which the corrosion-prone catalyst can be electrochemically stabilized through cathodic protection. The catalyst was further implemented in a laboratory-scale flow-cell electrolyzer under galvanostatic conditions, demonstrating its compatibility with continuous-flow operation. Together, these results establish DHBT-derived Fe foams as promising electrocatalysts for high-rate ammonia electrosynthesis and support their further evaluation in scaled flow-cell systems.
ER -