Electrochemical Ammonia Synthesis · 2021. 2. 16. · Ammonia. Science Advances4, no. 4 (April...
Transcript of Electrochemical Ammonia Synthesis · 2021. 2. 16. · Ammonia. Science Advances4, no. 4 (April...
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Nitricity
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Nitricity produces distributed nitrogen fertilizer using only air, water, and renewable electricity.
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Nitricity in action | team
3
Notable Awards
Jay Schwalbe Josh
McEnaney
Nico Pinkowski
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Nitricity in action | on-farm system
4
Notable Awards
Jay Schwalbe Josh
McEnaney
Nico Pinkowski
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Nitricity in action | on-farm system
5
Notable Awards
Jay Schwalbe Josh
McEnaney
Nico Pinkowski
Nitricity report 2020 growing season
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Solar + Agriculture
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Jay Schwalbe Josh
McEnaney
Nico Pinkowski
India is pushing 31 GW of solar to help farmers offset pumping and electrical needs
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Low soil resilience in China
Poor soil in Africa and South America
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We need to double food production by 2050, but we have finite resources!
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Incumbent technology
Pattabathula, Venkat, and Jim Richardson. “Introduction to Ammonia Production.” Back to Basics, 2016, 7.
Haber-Bosch:400 ̊C, 200 atm
N2 + 3H2 ⇌ 2NH3
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Incumbent technology - distribution
Pattabathula, Venkat, and Jim Richardson. “Introduction to Ammonia Production.” Back to Basics, 2016, 7.
N2 + 3H2 ⇌ 2NH3
Galloway, James N., and Ellis B. Cowling. “Reactive Nitrogen and The World: 200 Years of Change.” AMBIO 31, no. 2 (March 2002): 64–71.
Vegetarian
Carnivorous
14% N used
4% N used
Haber-Bosch:400 ̊C, 200 atm
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Pattabathula, Venkat, and Jim Richardson. “Introduction to Ammonia Production.” Back to Basics, 2016, 7.
N2 + 3H2 ⇌ 2NH3
Galloway, James N., and Ellis B. Cowling. “Reactive Nitrogen and The World: 200 Years of Change.” AMBIO 31, no. 2 (March 2002): 64–71.
53% N lost in distribution and to runoff
Haber-Bosch:400 ̊C, 200 atm
Incumbent technology - distribution
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N2O emissions
Appendix
CALIFORNIA AGRICULTURE • VOLUME 71, NUMBER 3
N2O emitted from microbial activity in both ammonia oxidation (nitrification) and nitrate reduction (denitrification)
Excess N increases emissions
Low oxygen increases denitrification
High frequency application has been shown to reduce N2O
https://www.sciencedirect.com/science/article/abs/pii/S0167880916303954?via%3Dihub, Scientific RepoRts | 6:30349 | DOI: 10.1038/srep30349
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Production1.4% of global CO2
Distribution0.07% of global CO2
Application6.1% of global CO2eq
Farmers pay 3x-5x gate cost
Centralized, extreme CapEx
14
Ineffective nutrient management
Problems that require breakthrough solutions
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Production1.4% of global CO2
Distribution0.07% of global CO2
Application6.1% of global CO2eq
Farmers pay 3x-5x gate cost
Centralized, extreme CapEx
15
Ineffective nutrient management
Problems that require breakthrough solutions
2.88 Gt CO2eq
High $/acre
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Potential for Electrification
1% efficient
100% efficient
Solar cell area required for NH3
synthesis (blue) is strongly dependent on efficiency.
approach Cell
potenti
al [V]
Faradaic
effecien
cy
kWh/kg
NH3
Haber-bosch +
water splitting1
NA NA 18.3
Electrochemical
limit
1.23 100 6.9
Low FE
electrochemical
1.23 1 690
High
overpotential
4 100 22.4
1Cussler, Edward et. al. “Ammonia Synthesis at Low Pressure.” JoVE no. 126 (August 23, 2017): e55691.
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Electrochemistry – a possible distributed competitor
N2 + 6H+ + 6e- ⇌ 2NH3
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Electrochemistry – a possible distributed competitor
V
N2 + 6H+ + 6e- ⇌ 2NH3
cathodeanode
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Electrochemistry – a possible distributed competitor
V
N2 + 6H+ + 6e- ⇌ 2NH3
electrolyte
Ions (H+)
electrons
cathodeanode
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Electrochemistry – a possible distributed competitor
N2 + 6H+
2NH3
V
6e-
N2 + 6H+ + 6e- ⇌ 2NH3
cathodeanode
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Electrochemistry – a possible distributed competitor
N2 + 6H+
2NH3
3 H2O
3/2 O2 + 6H+
6e-
V
6e-
N2 + 6H+ + 6e- ⇌ 2NH3
cathodeanode
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Basic Definitions
N2 + 6H+
2NH3
3 H2O
3/2 O2 + 6H+
6e-
V
6e-
N2 + 6H+ + 6e- ⇌ 2NH3
Faradaic Efficiency = 𝐶ℎ𝑎𝑟𝑔𝑒 𝑡𝑜 𝑁𝐻3
𝑇𝑜𝑡𝑎𝑙 𝐶ℎ𝑎𝑟𝑔𝑒
cathodeanode
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The Voltage Determines the Driving Force
N2 + 6H+
2NH3
3 H2O
3/2 O2 + 6H+
6e-
V
6e-
N2 + 6H+ + 6e- ⇌ 2NH3
Faradaic Efficiency = 𝐶ℎ𝑎𝑟𝑔𝑒 𝑡𝑜 𝑁𝐻3
𝑇𝑜𝑡𝑎𝑙 𝐶ℎ𝑎𝑟𝑔𝑒
Volts [J/C]1.230
Hydrogen EvolutionReaction(pH=1) (HER)
Oxygen EvolutionReaction (OER)
cathodeanode
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The Voltage Determines the Driving Force
N2 + 6H+
2NH3
3 H2O
3/2 O2 + 6H+
6e-
V
6e-
N2 + 6H+ + 6e- ⇌ 2NH3
Faradaic Efficiency = 𝐶ℎ𝑎𝑟𝑔𝑒 𝑡𝑜 𝑁𝐻3
𝑇𝑜𝑡𝑎𝑙 𝐶ℎ𝑎𝑟𝑔𝑒
Volts [J/C]1.230
Nitrogen Reduction (N2RR)0.09 v. HER
HEROER
cathodeanode
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The Voltage Determines the Driving Force
N2 + 6H+
2NH3
3 H2O
3/2 O2 + 6H+
6e-
V
6e-
N2 + 6H+ + 6e- ⇌ 2NH3
Faradaic Efficiency = 𝐶ℎ𝑎𝑟𝑔𝑒 𝑡𝑜 𝑁𝐻3
𝑇𝑜𝑡𝑎𝑙 𝐶ℎ𝑎𝑟𝑔𝑒
Volts [J/C]1.230
HER OER
N2RR
cathodeanode
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Simplified Mechanism of Ammonia Synthesis
Singh, Aayush R., Brian A. Rohr, Michael J. Statt, Jay A. Schwalbe, Matteo Cargnello, and Jens K. Nørskov. “Strategies toward Selective Electrochemical Ammonia Synthesis.” ACS Catalysis, July 29, 2019, 8316–24.
N≡N
H+
e-
N
N
=
H+ 2H+ + 2e-
N≡
+ 3H+ + 3e-
NH3 NH3
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Simplified Version of the Energetic Landscape
Singh, Aayush R., Brian A. Rohr, Michael J. Statt, Jay A. Schwalbe, Matteo Cargnello, and Jens K. Nørskov. “Strategies toward Selective Electrochemical Ammonia Synthesis.” ACS Catalysis, July 29, 2019, 8316–24.
N≡N
H+
e-
N
N
=
H
+ 2H+ + 2e-
+ 3H+ + 3e-
N≡
NH3
NH3
EnergyMore Negative Voltage
Limiting Potential Applied
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The Hydrogen evolution reaction presents a fundamental challenge
Singh, Aayush R., Brian A. Rohr, Michael J. Statt, Jay A. Schwalbe, Matteo Cargnello, and Jens K. Nørskov. “Strategies toward Selective Electrochemical Ammonia Synthesis.” ACS Catalysis, July 29, 2019, 8316–24.
Easier
HER
Nitrogen Reduction
1% faradaic efficiency
100% faradaic efficiency
Solar cell area required for NH3
synthesis (blue) is strongly dependent on faradaic efficiency.
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DFT Gives us a Starting Point
Singh, Aayush R., Brian A. Rohr, Michael J. Statt, Jay A. Schwalbe, Matteo Cargnello, and Jens K. Nørskov. “Strategies toward Selective Electrochemical Ammonia Synthesis.” ACS Catalysis, July 29, 2019, 8316–24.
HER
Nitrogen Reduction
H
H+N2
H H HHH
e-
Catalyst Surface
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DFT Gives us a Starting Point
Singh, Aayush R., Brian A. Rohr, Michael J. Statt, Jay A. Schwalbe, Matteo Cargnello, and Jens K. Nørskov. “Strategies toward Selective Electrochemical Ammonia Synthesis.” ACS Catalysis, July 29, 2019, 8316–24.
HER
Nitrogen Reduction
H
H+N2
H H HHH
e-
Catalyst Surface
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Even the Most Exciting Cases Don’t Work in Water
Jay Schwalbe, unpublished dataAndersen et. al. nature 1, 2019
H
H+N2
H H HHH
e--0.01
0.01
0.03
350 550 750
abso
rban
ce
Wavelength [nm]
N2RRconditions
Negative control
FE<1% - Not Statistically Significant
Catalyst Surface
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Even the Most Exciting Candidates Don’t Work in Water
Jay Schwalbe, unpublished dataAndersen et. al. nature 1, 2019
H
H+N2
H H HHH
e--0.01
0.01
0.03
350 550 750
abso
rban
ce
Wavelength [nm]
N2RRconditions
Negative control
FE<1% - Not Statistically Significant
Catalyst Surface
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Model Development
Singh, Aayush R., Brian A. Rohr, Michael J. Statt, Jay A. Schwalbe, Matteo Cargnello, and Jens K. Nørskov. “Strategies toward Selective Electrochemical Ammonia Synthesis.” ACS Catalysis, July 29, 2019, 8316–24.
H
H+
H H HHH
𝑟𝐻 = 𝑘𝐻𝜃𝐻 ǁ𝑐𝐻+ ǁ𝑐𝑒− ≅ 𝑘𝐻 ǁ𝑐𝐻+ ǁ𝑐𝑒−
e-
Catalyst Surface
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Model Development
Singh, Aayush R., Brian A. Rohr, Michael J. Statt, Jay A. Schwalbe, Matteo Cargnello, and Jens K. Nørskov. “Strategies toward Selective Electrochemical Ammonia Synthesis.” ACS Catalysis, July 29, 2019, 8316–24.
Catalyst Surface
H
H+N2
H H HHH
𝑟𝐻 = 𝑘𝐻𝜃𝐻 ǁ𝑐𝐻+ ǁ𝑐𝑒− ≅ 𝑘𝐻 ǁ𝑐𝐻+ ǁ𝑐𝑒−
e-
𝑟𝑁 = 𝑘𝑁𝜃𝑁2 ǁ𝑐𝐻+ ǁ𝑐𝑒− ≅ 𝑘𝑁𝐾𝑁𝐾𝐻
ǁ𝑐𝑁2
𝜃𝑁2 =𝐾𝑁 ǁ𝑐𝑁2
1+𝐾𝐻 ǁ𝑐𝐻+ ǁ𝑐𝑒−+𝐾𝑁 ǁ𝑐𝑁2≅
𝐾𝑁 ǁ𝑐𝑁2𝐾𝐻 ǁ𝑐𝐻+ ǁ𝑐𝑒−
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Model Development
Singh, Aayush R., Brian A. Rohr, Michael J. Statt, Jay A. Schwalbe, Matteo Cargnello, and Jens K. Nørskov. “Strategies toward Selective Electrochemical Ammonia Synthesis.” ACS Catalysis, July 29, 2019, 8316–24.
H
H+N2
H H HHH
𝑟𝐻 = 𝑘𝐻𝜃𝐻 ǁ𝑐𝐻+ ǁ𝑐𝑒− ≅ 𝑘𝐻 ǁ𝑐𝐻+ ǁ𝑐𝑒−
e-
𝑟𝑁 = 𝑘𝑁𝜃𝑁2 ǁ𝑐𝐻+ ǁ𝑐𝑒− ≅ 𝑘𝑁𝐾𝑁𝐾𝐻
ǁ𝑐𝑁2
𝑟𝑁𝑟𝐻=𝑘𝑁𝑘𝐻
∗𝐾𝑁𝐾𝐻
∗ǁ𝑐𝑁2
ǁ𝑐𝐻+ ǁ𝑐𝑒−
H+
H+
H+
H+
H+
H+
H+
H+
Water has too many protons!
Catalyst Surface
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Proposed Strategies
Singh, Aayush R., Brian A. Rohr, Michael J. Statt, Jay A. Schwalbe, Matteo Cargnello, and Jens K. Nørskov. “Strategies toward Selective Electrochemical Ammonia Synthesis.” ACS Catalysis, July 29, 2019, 8316–24.
𝑟𝐻 = 𝑘𝐻𝜃𝐻 ǁ𝑐𝐻+ ǁ𝑐𝑒− ≅ 𝑘𝐻 ǁ𝑐𝐻+ ǁ𝑐𝑒−
𝑟𝑁 = 𝑘𝑁𝜃𝑁2 ǁ𝑐𝐻+ ǁ𝑐𝑒− ≅ 𝑘𝑁𝐾𝑁𝐾𝐻
ǁ𝑐𝑁2
𝑟𝑁𝑟𝐻=𝑘𝑁𝑘𝐻
∗𝐾𝑁𝐾𝐻
∗ǁ𝑐𝑁2
ǁ𝑐𝐻+ ǁ𝑐𝑒−
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Proposed Strategies
Singh, Aayush R., Brian A. Rohr, Michael J. Statt, Jay A. Schwalbe, Matteo Cargnello, and Jens K. Nørskov. “Strategies toward Selective Electrochemical Ammonia Synthesis.” ACS Catalysis, July 29, 2019, 8316–24.
𝑟𝐻 = 𝑘𝐻𝜃𝐻 ǁ𝑐𝐻+ ǁ𝑐𝑒− ≅ 𝑘𝐻 ǁ𝑐𝐻+ ǁ𝑐𝑒−
𝑟𝑁 = 𝑘𝑁𝜃𝑁2 ǁ𝑐𝐻+ ǁ𝑐𝑒− ≅ 𝑘𝑁𝐾𝑁𝐾𝐻
ǁ𝑐𝑁2
𝑟𝑁𝑟𝐻=𝑘𝑁𝑘𝐻
∗𝐾𝑁𝐾𝐻
∗ǁ𝑐𝑁2
ǁ𝑐𝐻+ ǁ𝑐𝑒−
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Experimental Measurements of Ammonia Synthesis
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Ammonia rates are observed to be low
39
N co
nta
inin
g
po
lymer
Ca
rbo
n
na
no
spikes
Ion
ic liqu
id
electrolyte
Eth
ylene
dia
min
e
“A Physical Catalyst for the Electrolysis of Nitrogen to Ammonia.” Science Advances 4, no. 4 (April 2018): e1700336.
“Ammonia Electrosynthesis with High Selectivity under Ambient Conditions via a Li+ Incorporation Strategy.” Journal of the American Chemical Society 139, no. 29 (July 26, 2017): 9771–74.
“Electro-Synthesis of Ammonia from Nitrogen at Ambient Temperature and Pressure in Ionic Liquids.” Energy & Environmental Science 10, no. 12 (2017): 2516–20.
“Electrochemical Synthesis of Ammonia from Water and Nitrogen in Ethylenediamine under Ambient Temperature and Pressure.” J. Electrochem. Soc. 163 (2016).
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Ammonia rates are observed to be low
40
N co
nta
inin
g
po
lymer
Ca
rbo
n
na
no
spikes
Ion
ic liqu
id
electrolyte
Eth
ylene
dia
min
e
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Low enough to be in the range of common contamination
41
Left: >5ppm ~ 275uM contamination from adhesive on vial top
N co
nta
inin
g
po
lymer
Ca
rbo
n
na
no
spikes
Ion
ic liqu
id
electrolyte
Ethylen
e d
iam
ine
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Some critical literature
42
“A Re-Evaluation of Sn(II) Phthalocyanine as a Catalyst for the Electrosynthesis of Ammonia.” Electrochimica Acta 258 (December 2017): 618–22.
“Critical Assessment of the Electrocatalytic Activity of Vanadium and Niobium Nitrides toward Dinitrogen Reduction to Ammonia.” ACS Sustainable Chemistry & Engineering, February 5, 2019.
Detect ammonia with N2 supplied
Amount greater than with Argon or
no Current?
Eliminate sources of contamination
Verify with purified 15N2 experiment
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43
Searle, Phillip L. “The Berthelot or Indophenol Reaction and Its Use in the Analytical Chemistry of Nitrogen. A Review.” Analyst 109, no. 5 (January 1, 1984): 549–68.
55 µM 165 µM0 µM
Ammonia detection is possible with a number of techniques -Colorimetric
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Ammonia detection is possible with a number of techniques -Colorimetric
44Thanks, Chenshuang Zhou!
Water
Searle, Phillip L. “The Berthelot or Indophenol Reaction and Its Use in the Analytical Chemistry of Nitrogen. A Review.” Analyst 109, no. 5 (January 1, 1984): 549–68.
55 µM 165 µM0 µM
More NH3
Pea
k a
rea
ab
sorb
an
ce
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45
Thanks, Chengshuang Zhou!
Water
Propylene Carbonate
Searle, Phillip L. “The Berthelot or Indophenol Reaction and Its Use in the Analytical Chemistry of Nitrogen. A Review.” Analyst 109, no. 5 (January 1, 1984): 549–68.
55 µM 165 µM0 µM
More NH3
More NH3
Pea
k a
rea
Pea
k a
rea
ab
sorb
an
cea
bso
rba
nce
Wavelength [nm] uM NH3
Ammonia detection is possible with a number of techniques -Colorimetric
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Ammonia detection is possible with a number of techniques - NMR
46
300 µM200 µM100 µM
Selective excitation of ammonia
Nielander, Adam C., Joshua M. McEnaney, Jay A. Schwalbe, et. al. ACS Catalysis 9, no. 7 (July 5, 2019): 5797–5802.
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Ammonia detection is possible with a number of techniques - NMR
47
300 µM200 µM100 µM
Selective excitation of ammonia
Solvent not strongly detected
Nielander, Adam C., Joshua M. McEnaney, Jay A. Schwalbe, et. al. ACS Catalysis 9, no. 7 (July 5, 2019): 5797–5802.
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Ammonia detection is possible with a number of techniques - NMR
48
300 µM200 µM100 µM
Selective excitation of ammonia
Solvent not strongly detected
Detect ammonia with N2 supplied
Amount greater than with Argon or
no Current?
Detect ammonia with N2 supplied
Amount greater than with Argon or
no Current?
Detect ammonia with N2 supplied
Amount greater than with Argon or
no Current?
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Schematic of Electrochemical Experiment
49
V Gas Supply
Voltage Supply
Electrolyte:THF, 0.1M LiClO4, 1 v% EthanolMo cathode
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Schematic of Electrochemical Experiment
V Gas Supply
Voltage Supply
Electrolyte:THF, 0.1M LiClO4, 1 v% EthanolMo cathode
More Protons
Tsuneto, Akira, Akihiko Kudo, and Tadayoshi Sakata. Chemistry Letters 22, no. 5 (May 1, 1993): 851–54.
H2
NH3
Fara
da
ic E
ffic
ien
cy
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Schematic of Electrochemical Experiement
51
V Gas Supply
Voltage Supply
Electrolyte:THF, 0.1M LiClO4, 1 v% EthanolMo cathode
IncreasingAmmoniaa
bso
rba
nce
Wavelength [nm]
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Schematic of Electrochemical Experiement
52
IncreasingAmmonia
No Ammonia Expected
ab
sorb
an
ce
Wavelength [nm]
ab
sorb
an
ce
Wavelength [nm]
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NMR Has Less Baseline Variation
53
No Current, N2
Current, Ar
Current, N2
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NMR Gives More Clear Results
54
No Current, N2
Current, Ar
Current, N2
V
Verify with purified 15N2 experiment
Detect ammonia with N2 supplied
Amount greater than with Argon or
no Current?
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15N labelling experiments
15N2
15NH3
14NH3
Only adventitious
Genuine
V
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Contamination in 15N2
15N2
15NH3
14NH3
Only adventitious
Contamination+Genuine
15N2O
V
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Contamination in 15N2
Wavenumber [cm-1]
ab
sorb
an
ce
Spectra of 15N2O
Spectra of commercial 15N2
15N2
15NH3
14NH3
Only adventitious
Contamination+Genuine
15N2O
V
“The Contamination of Commercial 15N2 Gas Stocks with 15N–Labeled Nitrate and Ammonium and Consequences for Nitrogen Fixation Measurements.” PLoS ONE 9, no. 10 (October 17, 2014): e110335.
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Gas must be purified and quantitative agreement achieved
Andersen, Suzanne Z., Viktor Čolić, Sungeun Yang, Jay A. Schwalbe, Adam C. Nielander, Joshua M. McEnaney, Kasper Enemark-Rasmussen, et al. “A Rigorous Electrochemical Ammonia Synthesis Protocol with Quantitative Isotope Measurements.” Nature, May 22, 2019, 1.
Gas purification and recycling set-up at DTU
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Gas must be purified and quantitative agreement achieved
Andersen, Suzanne Z., Viktor Čolić, Sungeun Yang, Jay A. Schwalbe, Adam C. Nielander, Joshua M. McEnaney, Kasper Enemark-Rasmussen, et al. “A Rigorous Electrochemical Ammonia Synthesis Protocol with Quantitative Isotope Measurements.” Nature, May 22, 2019, 1.
Gas purification and recycling set-up at DTU
14NH3
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Gas must be purified and quantitative agreement achieved
Andersen, Suzanne Z., Viktor Čolić, Sungeun Yang, Jay A. Schwalbe, Adam C. Nielander, Joshua M. McEnaney, Kasper Enemark-Rasmussen, et al. “A Rigorous Electrochemical Ammonia Synthesis Protocol with Quantitative Isotope Measurements.” Nature, May 22, 2019, 1.
Gas purification and recycling set-up at DTU
14NH3
15NH3
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Gas must be purified and quantitative agreement achieved
Andersen, Suzanne Z., Viktor Čolić, Sungeun Yang, Jay A. Schwalbe, Adam C. Nielander, Joshua M. McEnaney, Kasper Enemark-Rasmussen, et al. “A Rigorous Electrochemical Ammonia Synthesis Protocol with Quantitative Isotope Measurements.” Nature, May 22, 2019, 1.
Gas purification and recycling set-up at DTU
14NH3
15NH3 Verify with purified 15N2 experiment
Detect ammonia with N2 supplied
Amount greater than with Argon or
no Current?
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Questions?