Dioxide Materials was founded in 2009 in Champaign, Illinois, and is now headquartered in Boca Raton, Florida. Its main business is to develop technology to lower the world's carbon footprint. Dioxide Materials is developing technology to convert carbon dioxide, water and renewable energy into carbon-neutral gasoline (petrol) or jet fuel. Applications include CO2 recycling,[1] sustainable fuels production [1] and reducing curtailment of renewable energy[2][3](i.e. renewable energy that could not be used by the grid[2]).

Dioxide Materials
Company typePrivate
IndustryChemical industry
GenreCarbon capture and storage, Ion-exchange membranes
FoundedSeptember 9, 2009; 15 years ago (2009-09-09) in Champaign, Illinois, US
Headquarters,
US
ProductsSustainion Alkaline Ionomers and Alkaline Ion Exchange Membranes, Carbon Dioxide and Water Electrolyzers
Websitedioxidematerials.com

Carbon Dioxide Electrolyzer Technology

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Carbon Dioxide electrolyzers are a major part of Dioxide Materials' business.[4] The work started in response to a Department of Energy challenge to find better catalysts for electrochemical reduction of carbon dioxide.[5] At the time the overpotential (i.e. wasted voltage) was too high, and the rate too low for practical applications.[5][6] Workers at Dioxide Materials theorized that a bifunctional catalyst consisting of a metal and an ionic liquid might lower the overpotential for electrochemical reduction of carbon dioxide. Indeed, it was found that the combination of two catalysts, silver nanoparticles and an ionic liquid solution containing equal volumes of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIM-BF4) and water, reduced the overpotential for CO2 conversion to carbon monoxide (CO) from about 1 volt to only 0.17 volts.[7] Workers from other laboratories have subsequently reproduced the findings on many metals, and with several ionic liquids.[8] Dioxide Materials has shown that a similar enhancement occurs during alkaline water electrolysis[9][10] and the hydrocarboxylation of acetylene [11] ("Reppe chemistry").

 
Dioxide Materials' proposed reaction pathway for CO2 electrolysis on silver in the presence (green) and absence (black) of EMIM

At this point, there is still some question about how the imidazolium is able to lower the overpotential for the electrochemical reduction of carbon dioxide. The first step in the electrolysis of CO2 is the addition of an electron into the CO2 or a molecular complex containing CO2. The resultant species is labeled "CO2¯" in the figure on the left. It requires at least an electron-volt of energy per molecule to form the species in the absence of the ionic liquid.[12] That electron-volt of energy is largely wasted during the reaction. Rosen at al[7] postulated that a new complex forms in presence of the ionic liquid so that 1 eV of energy is not wasted. The complex allows the reaction to follow the green pathway on the figure on the right. Recent work suggests that the new complex is a zwitterion[13] Other possible pathways (i.e. non-zwitterions) are discussed in Keith et al.[14] Rosen at al.[15] Verdaguer-Casadevall et al.[16] and Shi et al.[17]

Sustainion Membranes

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The structure of Sustainion 37

Unfortunately, ionic liquids were found to be too corrosive to be used in practical carbon dioxide electrolyzers. Ionic liquids are strong solvents. They dissolve/corrode the seals, carbon electrodes and other parts in commercial electrolyzers. As a result, they were difficult to be used in practice.

In order to avoid the corrosion, Dioxide Materials switched from ionic liquid catalysts to catalytic anion exchange polymers.[18][19] A number of polymers were tested and the imidazolium functionalized styrene polymer shown in the figure on the right showed the best performance.[18][20] The membranes were trade named Sustainion. The use of Sustainion membranes raised the current and lifetime of the CO2 electrolyzer into the commercially useful range.[21][22][23][24][25] Sustainion membranes have shown conductivities above 100 mS/cm under alkaline conditions at 60 °C,[10] stability for thousands of hours in 1M KOH,[10] and offer a physical mechanical stability that is useful for many different applications. The membranes showed a lifetime over 3000 hours in CO2 electrolyzers at high current densities.[26][10] More recent research has noted that a cell membrane that has an optimized cathode has the capability of running for up to 158 days at 200 mA/cm2 .[27]

References

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  1. ^ a b ARPA-E Brief: Converting CO2 Into Fuels and Chemicals  
  2. ^ a b Lori Bird, Jaquelin Cochran, and Xi Wang, Wind and Solar Energy Curtailment: Experience and Practices in the United States, NREL Report NREL/TP-6A20-60983, March 2014  
  3. ^ ARPA-E Brief: High Efficiency Hydrogen Production  
  4. ^ Dioxide Materials website
  5. ^ a b A. Bell et al. Basic research needs catalysts for energy, DOE PNNL-17214  
  6. ^ Halmann and Steinberg, "Greenhouse Gas Carbon Dioxide Mitigation," Lewis Publishers, 1999. ISBN 1-56670-284-4
  7. ^ a b Brian A. Rosen, Amin Salehi-Khojin, Michael R. Thorson, W. Zhu, Devin T. Whipple, Paul J. A. Kenis, Richard I Masel *, Ionic Liquid-Mediated Selective Conversion of CO2 to CO at Low Overpotentials, Science Vol. 334 no. 6056 pp. 643-644 (2011) doi:10.1126/science.1209786.
  8. ^ Citations for Ionic Liquid-Mediated Selective Conversion of CO2 to CO at Low Overpotentials  
  9. ^ R. I. Masel, Z. Liu, and S. D. Sajjad Anion Exchange Membrane Electrolyzers Showing 1 A/cm2 at Less Than 2 V, ECS Transactions, 75 (14) 1143-1146 (2016) doi:10.1149/07514.1143ecst
  10. ^ a b c d Zengcai Liu, Syed Dawar Sajjad, Yan Gao, HongzhouYang. Jerry J.Kaczur. Richard I.Masel, The effect of membrane on an alkaline water electrolyzer, International Journal of Hydrogen Energy 42(50), 29661-29665 (2017) doi:10.1016/j.ijhydene.2017.10.050
  11. ^ Richard I. Masel, Zheng Richard Ni, Qingmei CHEN, Brian A. Rosen, Process for the sustainable production of acrylic acid, US Patent 9790161 [1]
  12. ^ Chemistry Views (Elsevier) Converting CO2 with Less Energy  
  13. ^ Mark Pellerite, Marina Kaplun, Claire Hartmann-Thompson, Krzysztof A. Lewinski, Nancy Kunz, Travis Gregar, John Baetzold, Dale Lutz, Matthew Quast, Zengcai Liu, Hongzhou Yang, Syed D. Sajjad, Yan Gao, and Rich Masel Imidazolium-Functionalized Polymer Membranes for Fuel Cells and Electrolyzers, ECS Trans. 2017 80(8): 945-956; doi:10.1149/08008.0945ecst
  14. ^ John A. Keith and Emily A. Carter, Theoretical Insights into Electrochemical CO2 Reduction Mechanisms Catalyzed by Surface-Bound Nitrogen Heterocycles, J. Phys. Chem. Lett., 2013, 4 (23), pp 4058–4063 doi:10.1021/jz4021519
  15. ^ Jonathan Rosen, Gregory S. Hutchings, Qi Lu, Sean Rivera, Yang Zhou, Dionisios G. Vlachos, and Feng Jiao, Mechanistic Insights into the Electrochemical Reduction of CO2 to CO on Nanostructured Ag Surfaces, ACS Catal., 2015, 5 (7), pp 4293–4299 doi:10.1021/acscatal.5b00840
  16. ^ Arnau Verdaguer-Casadevall, Christina W. Li‡, Tobias P. Johansson, Soren B. Scott, Joseph T. McKeown, Mukul Kumar, Ifan E. L. Stephens, Matthew W. Kanan*, and Ib Chorkendorff* Probing the Active Surface Sites for CO Reduction on Oxide-Derived Copper Electrocatalysts, J. Am. Chem. Soc., 2015, 137 (31), pp 9808–9811 doi:10.1021/jacs.5b06227
  17. ^ Chuan Shi, Heine A. Hansen, Adam C. Lauscheb, and Jens K. Nørskov, Trends in electrochemical CO2 reduction activity for open and close-packed metal surfaces, Phys. Chem. Chem. Phys., 2014,16, 4720-4727 doi:10.1039/C3CP54822H
  18. ^ a b R. I. Masel, Qingmei Chen, Zengcai liu, Robert Kutz, Ion Conducting Polymers, US patent 9580824  
  19. ^ Richard I. Masel, Amin Salehi-Khojin, Robert Kutz, Electrocatalytic process for carbon dioxide conversion, US Patent 981501  
  20. ^ Robert Brian Kutz, Qingmei Chen, Hongzhou Yang, Syed Dawar Sajjad, Zengcai Liu, Richard Masel, Sustainion Imidazolium-functionalized Polymers for Carbon Dioxide Electrolysis, Energy Technology 5, (6) 929-936 (2017) doi:10.1002/ente.201600636
  21. ^ R.F. Service, Two new ways to turn ‘garbage’ carbon dioxide into fuel Science, Sept 1, 2017  
  22. ^ Steven K Ritter, CO2 Electrolyzer Nears Commercialization, C&E News, Volume 93 Issue 13 | p. 30 . March 30, 2015 
  23. ^ Mark Harris, The entrepreneurs turning carbon dioxide into fuels, The Guardian, 14 Sept 2017  
  24. ^ SAVVY: Turning Carbon Dioxide into products New Straitus Times, Dec 3, 2017.  
  25. ^ Michael Foertsch, These methods turn CO2 into cheap energy, Wired, Sept 24, 2017 
  26. ^ Syed D. Sajjad, Yan Gao, Zengcai Liu, Hongzhou Yang and Rich Masel Tunable-High Performance Sustainion™ Anion Exchange Membranes for Electrochemical Applications ECS Transactions, 77(11): 1653-1656 (2017) doi:10.1149/07711.1653ecst
  27. ^ Zengcai Liu et al 2018 J. Electrochem. Soc. 165 J3371 DOI 10.1149/2.0501815jes