One simple and fast way to manufacture a useful product from CO2 is to capture the gas by, and then carry out electrolysis in molten alkali metal carbonates. Carbon electro-deposition in molten Li2CO3-Na2CO3-K2CO3 (molar ratio: 43.5:31.5:25.0) has been widely reported in literature. However, studies in each of the individual alkali metal carbonates either have received less attention or are simply lacking in literature. Electrochemical studies of these molten carbonates are important to understand their underlying processes and reactions during the electrolysis. In this work, cyclic voltammograms (CVs) were recorded in each of the above-mentioned molten alkali carbonate salts using a 0.25 mm diameter Pt wire working electrode. In molten Na2CO3 and K2CO3, the main cathodic reaction was likely the formation of alkali metal, while that in Li2CO3 was carbon deposition. The results also suggest that other competing reactions such as CO and alkali metal carbide formation are possible as well in different molten salts. On the CVs, the anodic current peaks observed are mostly associated with the oxidation of cathodic products. Flake/ring/sheet-like structures and quasi-spherical particles were observed in the produced carbon. The morphology of the carbon contained both amorphous and graphitic structures, which varied with different electrolysis variables.
Happiness V. Ijije
,
George Z. Chen
. Electrochemical manufacturing of nanocarbons from carbon dioxide in molten alkali metal carbonate salts: roles of alkali metal cations[J]. Advances in Manufacturing, 2016
, 4(1)
: 23
-32
.
DOI: 10.1007/s40436-015-0125-2
1. Aresta M, Dibenedetto A, Angelini A (2013) The use of solar energy can enhance the conversion of carbon dioxide into energyrich products: stepping towards artificial photosynthesis. Philos Trans R Soc A 371:20120111
2. Whipple DT, Kenis PJA (2010) Prospects of CO2 utilization via direct heterogeneous electrochemical reduction. J Phys Chem Lett 1:3451-3458
3. Mikkelsen M, Jørgensen M, Krebs FC (2010) The teraton challenge. a review of fixation and transformation of carbon dioxide. Energy Environ Sci 3:43-81
4. Kaneco S, Iiba K, Katsumata Het al (2007) Effect of sodium cation on the electrochemical reduction of CO2 at a copper electrode in methanol. J Solid State Electrochem 11:490-495
5. Kaneco S, Iiba K, Suzuki SK et al (1999) Electrochemical reduction of carbon dioxide to hydrocarbons with high faradaic efficiency in LiOH/Methanol. J Phys Chem B 103:7456-7460
6. Saeki T, Hashimoto K, Kimura N et al (1995) Electrochemical reduction of CO2 with high current density in a CO2 ? methanol medium II. CO formation promoted by tetrabutylammonium cation. J Electroanal Chem 390:77-82
7. Fisher BJ, Eisenberg R (1980) Electrocatalytic reduction of carbon dioxide by using macrocycles of nickel and cobalt. J Am Chem Soc 102:7361-7363
8. Zhou F, Liu S, Yang B et al (2014) Highly selective electrocatalytic reduction of carbon dioxide to carbon monoxide on silver electrode with aqueous ionic liquids. Electrochem Commun 46:103-106
9. Carlesi C, Carvajal D, Vasquez D et al (2014) Analysis of carbon dioxide-to-methanol direct electrochemical conversion mediated by an ionic liquid. Chem Eng Process 85:48-56
10. Rosen BA, Salehi-Khojin A, Thorson MR et al (2011) Ionic liquid-mediated selective conversion of CO2 to CO at low overpotentials. Science 334:643-644
11. Snuffin LL, Whaley LW, Yu L (2011) Catalytic electrochemical reduction of CO2 in ionic liquid EMIMBF3Cl. J Electrochem Soc 158:F155-F158
12. Barrosse-Antle LE, Compton RG (2009) Reduction of carbon dioxide in 1-butyl-3-methylimidazolium acetate. Chem Commun 3744-3746
13. Ingram MD, Baron B, Janz GJ (1966) The electrolytic deposition of carbon from fused carbonates. Electrochim Acta 11:1629-1639
14. Delimarskii YK, Gordis'kii OV, Grishchenko VF (1964) Cathode liberation of carbon from molten carbonates. Dokl Akad Nauk SSSR 156:650-651
15. DelimarskiiI YK, Shapova VI, Vasilenko VA et al (1975) Electrolytic production of pure carbon. Otkrytiya Izobret Prom Obraztsy Tovarnye Znaki 52:176-177
16. Siambun NJ, Mohamed H, Hu D et al (2011) Utilisation of carbon dioxide for electro-carburisation of mild steel in molten carbonate salts. J Electrochem Soc 158:H1117-H1124
17. Siambun NJ (2011) Electrolysis of molten carbonate salts and its applications. Dissertation, University of Nottingham, Nottingham
18. Lawrence RC (2013) Carbon from carbon dioxide via molten carbonate electrolysis: fundamental investigations. Dissertation, University of Nottingham, Nottingham
19. Yin H, Mao X, Tang D et al (2013) Capture and electrochemical conversion of CO2 to value-added carbon and oxygen by molten salt electrolysis. Energy Environ Sci 6:1538-1545
20. Tang D, Yin H, Mao X et al (2013) Effects of applied voltage and temperature on the electrochemical production of carbon powders from CO2 in molten salt with an inert anode. Electrochim Acta 114:567-573
21. Ijije HV, Lawrence RC, Siambun NJ et al (2014) Electro-deposition and re-oxidation of carbon in carbonate-containing molten salts. Faraday Discuss 172:105-116
22. Kawamura H, Ito Y (2000) Electrodeposition of cohesive carbon films on aluminum in a LiCl-KCl-K2CO3 melt. J Appl Electrochem 30:571-574
23. Massot L, Chamelot P, Bouyer F et al (2002) Electrodeposition of carbon films from molten alkaline fluoride media. Electrochim Acta 47:1949-1957
24. Ijije HV, Lawrence RC, Chen GZ (2014) Carbon electrodeposition in molten salts: electrode reactions and applications. RSC Adv 4:35808-35817
25. DelimarskiiI YK, Shapoval VI, Grishchenko VF et al (1970) Electrolysis of fused carbonates of alkali metals under pressure. Zh Prikl Khim 43:2634-2638
26. Dimitrov AT (2009) Study of molten Li2CO3 electrolysis as a method for production of carbon nanotubes. Maced Source 28:111-118
27. Ijije HV, Sun C, Chen GZ (2014) Indirect electrochemical reduction of carbon dioxide to carbon nanopowders in molten alkali carbonates: process variables and product properties. Carbon 73:163-174
28. Le Van K, Groult H, Lantelme F et al (2009) Electrochemical formation of carbon nano-powders with various porosities in molten alkali carbonates. Electrochim Acta 54:4566-4573
29. Mallard WG, Lindstrom PJ (ed) (1969) NIST chemistry webbook, NIST standard reference. NIST chemistry webbook, NIST standard reference database, National Institute of standards and technology, Gaithersburg
30. Novoselova IA, Oliinyk NF, Volkov SV et al (2008) Electrolytic synthesis of carbon nanotubes from carbon dioxide in molten salts and their characterization. Physica E 40:2231-2237
31. Delimarskii YK, Gordis'kii OV, Grishchenko VF (1965) Reactions taking place during electrolysis of fused carbonates. Ukr Khim Zh 31:32-37
32. Bartlett HE, Johnson KE (1967) Electrochemical studies in molten Li2CO3-Na2CO3. J Electrochem Soc 114:457-461
33. Lorenz PK, Janz GJ (1970) Electrolysis of molten carbonates: anodic and cathodic gas evolving reactions. Electrochim Acta 15:1025-1035
34. Lantelme F, Kaplan B, Groult H et al (1999) Mechanism for elemental carbon formation in molecular ionic liquids. J Mol Liq 83:255-269
35. Chen GZ, Kinloch I, Shaffer MSP et al (1998) Electrochemical investigation of the formation of carbon nanotubes in molten salts. High Temp Mater Processes (New York) 2:459-469
36. Bartlett HE, Johnson KE (1967) Electrochemical studies in molten Li2CO3-Na2CO3. J Electrochem Soc 114:457-461
37. Ito Y, Shimada T, Kawamura H (1992) Electrochemical formation of thin carbon film from molten chloride system. Proc Electrochem Soc 16:574-585
38. Wang H, Siambun NJ, Yu L et al (2012) A robust alumina membrane reference electrode for high temperature molten salts. J Electrochem Soc 159(9):H740-H746
39. Chen HL, Jin XB, Yu LP et al (2014) Influences of graphite anode area on electrolysis of solid metal oxides in molten salts. J Solid State Electrochem 18(12):3317-3325
