Elementary kinetics of nitrogen electroreduction on Fe surfaces
- Pennsylvania State Univ., University Park, PA (United States). Dept. of Chemical Engineering
- Univ. of North Carolina, Wilmington, NC (United States). Dept. of Chemistry and Biochemistry
Electrochemical ammonia synthesis could provide a sustainable and efficient alternative to the energy intensive Haber-Bosch process. Development of an active and selective N2 electroreduction catalyst requires mechanism determination to aid in connecting catalyst composition and structure to performance. Density functional theory calculations are used to examine the elementary step energetics of associative N2 reduction mechanisms on two low index Fe surfaces. Interfacial water molecules in the Heyrovsky-like mechanism help lower some of the elementary activation barriers. Electrode potential dependent barriers show that cathodic potentials below -1.5 V-RHE are necessary to give a significant rate of N2 electroreduction. DFT barriers suggest a larger overpotential than expected based on elementary reaction free energies. Linear Brønsted-Evans-Polanyi relationships do not hold across N–H formation steps on these surfaces, further confirming that explicit barriers should be considered in DFT studies of the nitrogen reduction reaction.
- Research Organization:
- Pennsylvania State Univ., University Park, PA (United States); University of North Carolina, Wilmington, NC (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF)
- Grant/Contract Number:
- SC0016529; ACI-1053575; DGE-1449785
- OSTI ID:
- 1482070
- Journal Information:
- Journal of Chemical Physics, Vol. 150, Issue 4; ISSN 0021-9606
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Elementary kinetics of nitrogen electroreduction to ammonia on late transition metals
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journal | January 2019 |
Special Topic on Interfacial Electrochemistry and Photo(electro)catalysis
|
journal | January 2019 |
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