Abstract
The development of a sustainable ammonia synthesis by proton-coupled electroreduction of dinitrogen (N2) requires knowledge of the thermodynamics described by standard reduction potentials. The first collection of N2 reduction standard potentials in an organic solvent are reported here. The potentials for reduction of N2 to ammonia (NH3), hydrazine (N2H4), and diazene (N2H2) in acetonitrile (MeCN) solution are derived using thermochemical cycles. Ammonia is thermodynamically favored, with a 0.43 V difference between NH3 and N2H4 and a 1.26 V difference between NH3 and N2H2. The thermodynamics for reduction of N2 to the protonated products ammonium (NH4+) and hydrazinium (N2H5+) under acidic conditions are also presented. Comparison with the H+/H2 potential in MeCN reveals a 63 mV thermodynamic preference for N2 reduction to NH3 over H2 production. Combined with knowledge of the kinetics of electrode-catalyzed H2 evolution, a wide working region is identified to guide future electrocatalytic studies.
| Original language | English |
|---|---|
| Pages (from-to) | 698-704 |
| Number of pages | 7 |
| Journal | ACS Energy Letters |
| Volume | 1 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Oct 14 2016 |
Fingerprint
ASJC Scopus subject areas
- Chemistry (miscellaneous)
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Energy Engineering and Power Technology
- Materials Chemistry
Cite this
Evaluating the Thermodynamics of Electrocatalytic N2 Reduction in Acetonitrile. / Lindley, Brian M.; Appel, Aaron; Krogh-Jespersen, Karsten; Mayer, James M.; Miller, Alexander J.M.
In: ACS Energy Letters, Vol. 1, No. 4, 14.10.2016, p. 698-704.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Evaluating the Thermodynamics of Electrocatalytic N2 Reduction in Acetonitrile
AU - Lindley, Brian M.
AU - Appel, Aaron
AU - Krogh-Jespersen, Karsten
AU - Mayer, James M.
AU - Miller, Alexander J.M.
PY - 2016/10/14
Y1 - 2016/10/14
N2 - The development of a sustainable ammonia synthesis by proton-coupled electroreduction of dinitrogen (N2) requires knowledge of the thermodynamics described by standard reduction potentials. The first collection of N2 reduction standard potentials in an organic solvent are reported here. The potentials for reduction of N2 to ammonia (NH3), hydrazine (N2H4), and diazene (N2H2) in acetonitrile (MeCN) solution are derived using thermochemical cycles. Ammonia is thermodynamically favored, with a 0.43 V difference between NH3 and N2H4 and a 1.26 V difference between NH3 and N2H2. The thermodynamics for reduction of N2 to the protonated products ammonium (NH4+) and hydrazinium (N2H5+) under acidic conditions are also presented. Comparison with the H+/H2 potential in MeCN reveals a 63 mV thermodynamic preference for N2 reduction to NH3 over H2 production. Combined with knowledge of the kinetics of electrode-catalyzed H2 evolution, a wide working region is identified to guide future electrocatalytic studies.
AB - The development of a sustainable ammonia synthesis by proton-coupled electroreduction of dinitrogen (N2) requires knowledge of the thermodynamics described by standard reduction potentials. The first collection of N2 reduction standard potentials in an organic solvent are reported here. The potentials for reduction of N2 to ammonia (NH3), hydrazine (N2H4), and diazene (N2H2) in acetonitrile (MeCN) solution are derived using thermochemical cycles. Ammonia is thermodynamically favored, with a 0.43 V difference between NH3 and N2H4 and a 1.26 V difference between NH3 and N2H2. The thermodynamics for reduction of N2 to the protonated products ammonium (NH4+) and hydrazinium (N2H5+) under acidic conditions are also presented. Comparison with the H+/H2 potential in MeCN reveals a 63 mV thermodynamic preference for N2 reduction to NH3 over H2 production. Combined with knowledge of the kinetics of electrode-catalyzed H2 evolution, a wide working region is identified to guide future electrocatalytic studies.
UR - http://www.scopus.com/inward/record.url?scp=85021355019&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85021355019&partnerID=8YFLogxK
U2 - 10.1021/acsenergylett.6b00319
DO - 10.1021/acsenergylett.6b00319
M3 - Article
VL - 1
SP - 698
EP - 704
JO - ACS Energy Letters
JF - ACS Energy Letters
SN - 2380-8195
IS - 4
ER -