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Investigation on the application of platinum anode towards direct electrochemical reduction of solid metal oxides in CaCl2–CaO melt

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Abstract

Molten CaCl2–CaO system is a suitable electrolyte medium for reducing metal oxides to metal by in-situ electro-generated calcium metal. The graphite anode, which acts as a reactive anode in this melt, leads to several parasitic reactions and decreases the current efficiency. The present study investigates the usage of platinum anode towards the direct oxide electrochemical reduction of ThO2 and NiO by electro-generated calcium in CaCl2–1 wt % CaO melt at 900 °C. Primarily, the anodic behavior of platinum electrode was investigated using electrochemical techniques such as linear sweep voltammetry, potentiodynamic polarization, electrochemical impedance spectroscopy, cyclic voltammetry and potentiostatic electrolysis in CaCl2–CaO melt. Platinum exhibited the most anodic polarization potential, positive corrosion potential, and highest oxidation resistance compared to nickel and gold. It also showed a clearly demarcated potential window for oxygen evolution and much better physico-chemical stability compared to gold electrode. Electro-calciothermic reduction experiments conducted with ThO2 and NiO cathodes using platinum anode demonstrated the feasibility of metallization, and platinum's mass loss rate in these experiments was found to be much less (in the order of ~ 0.016 g cm−2 h−1). The study showed that platinum could be used as an anode in the electrochemical reduction of solid metal oxides in CaCl2–1 wt % CaO melt with minimal mass loss.

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References

  1. Chen GZ, Fray DJ, Farthing TW (2000) Direct electrochemical reduction of titanium dioxide to titanium in molten calcium chloride. Nature 407:361–364. https://doi.org/10.1038/35030069

    Article  ADS  CAS  PubMed  Google Scholar 

  2. Ono K, Suzuki RO (2002) A new concept for producing Ti sponge: calciothermic reduction. JOM 54:59–61. https://doi.org/10.1007/BF02701078

    Article  CAS  Google Scholar 

  3. Abdelkader AM, Kilby KT, Cox A, Fray DJ (2013) DC voltammetry of electro-deoxidation of solid oxides. Chem Rev 113:2863–2886. https://doi.org/10.1021/cr200305x

    Article  CAS  PubMed  Google Scholar 

  4. Xiao W, Wang D (2014) The electrochemical reduction processes of solid compounds in high temperature molten salts. Chem Soc Rev 43:3215–3228. https://doi.org/10.1039/C3CS60327J

    Article  MathSciNet  CAS  PubMed  Google Scholar 

  5. Chen GZ, Fray DJ (2020) Invention and fundamentals of the FFC Cambridge process. Extr Metall Titan Conv Recent Adv Extr Prod Titan Met. https://doi.org/10.1016/B978-0-12-817200-1.00011-9

    Article  Google Scholar 

  6. Suzuki RO, Noguchi H, Haraguchi Y, Natsui S, Kikuchi T (2018) (Invited) Metal production in CaCl2-based melts. ECS Trans 86:45. https://doi.org/10.1149/08614.0045ECST

    Article  CAS  Google Scholar 

  7. Suzuki RO, Natsui S, Kikuchi T (2020) OS process: calciothermic reduction of TiO2 via CaO electrolysis in molten CaCl2. Extr Metall Titan Conv Recent Adv Extr Prod Titan Met. https://doi.org/10.1016/B978-0-12-817200-1.00012-0

    Article  Google Scholar 

  8. Osaki S, Sakai H, Suzuki RO (2010) Direct production of Ti–29Nb–13Ta–4.6Zr biomedical alloy from oxide mixture in molten CaCl2. J Electrochem Soc 157:117. https://doi.org/10.1149/1.3435302/XML

    Article  Google Scholar 

  9. Enmei R, Kikuchi T, Suzuki RO (2013) Production of Nb–Ti–Ni alloy in molten CaCl2. Electrochim Acta 100:257–260. https://doi.org/10.1016/J.ELECTACTA.2012.11.044

    Article  CAS  Google Scholar 

  10. Suzuki RO, Teranuma K, Ono K (2003) Calciothermic reduction of titanium oxide and in-situ electrolysis in molten CaCl2. Metall Mater Trans B 34:287–295. https://doi.org/10.1007/S11663-003-0074-1/METRICS

    Article  Google Scholar 

  11. Suzuki RO, Fukui S (2004) Reduction of TiO2 in molten CaCl2 by Ca deposited during CaO electrolysis. Mater Trans 45:1665–1671

    Article  CAS  Google Scholar 

  12. Chen GZ (2020) Interactions of molten salts with cathode products in the FFC Cambridge process. Int J Miner Metall Mater 27:1572–1587. https://doi.org/10.1007/s12613-020-2202-1

    Article  CAS  Google Scholar 

  13. Sri Maha Vishnu D, Sure J, Mohandas KS (2015) Corrosion of high density graphite anodes during direct electrochemical de-oxidation of solid oxides in molten CaCl2 medium. Carbon 93:782–792. https://doi.org/10.1016/j.carbon.2015.05.093

    Article  CAS  Google Scholar 

  14. Ueda I, Baba M, Kikuchi T, Suzuki RO (2013) Formation of niobium powder by electrolysis in molten salt. Electrochim Acta 100:269–274. https://doi.org/10.1016/J.ELECTACTA.2013.01.054

    Article  CAS  Google Scholar 

  15. Jones AH, Watson R, Paget T, Campbell-Kelly R, Caldwell T, Fray DJ (2015) Electrochemical reduction of plutonium oxide in molten CaCl2-CaO. J Nucl Fuel Cycle Waste Technol 13:1–5. https://doi.org/10.7733/jnfcwt.2015.13.s.1

    Article  CAS  Google Scholar 

  16. Mukherjee A, Kumaresan R, Joseph K (2021) Studies on direct electrochemical de-oxidation of solid ThO2 in calcium chloride based melts. J Electrochem Soc 168:72502. https://doi.org/10.1149/1945-7111/ac0ec8

    Article  CAS  Google Scholar 

  17. McGregor K, Frazer E, Urban A, Pownceby M, Deutscher R (2006) Development of inert anode materials for electrowinning in calcium chloride melts. ECS Trans 2:369–380. https://doi.org/10.1149/1.2196026

    Article  CAS  Google Scholar 

  18. Ge J, Zou X, Almassi S, Ji L, Chaplin BP, Bard AJ (2019) Electrochemical production of Si without generation of CO2 based on the use of a dimensionally stable anode in molten CaCl2. Angew Chem Int Ed 58:16223–16228. https://doi.org/10.1002/anie.201905991

    Article  CAS  Google Scholar 

  19. Barnett R, Kilby KT, Fray DJ (2009) Reduction of tantalum pentoxide using graphite and tin-oxide-based anodes via the FFC-Cambridge process. Metall Mater Trans B 40:150–157. https://doi.org/10.1007/s11663-008-9219-6

    Article  CAS  Google Scholar 

  20. Kilby KT, Jiao S, Fray DJ (2010) Current efficiency studies for graphite and SnO2-based anodes for the electro-deoxidation of metal oxides. Electrochim Acta 55:7126–7133. https://doi.org/10.1016/j.electacta.2010.06.049

    Article  CAS  Google Scholar 

  21. Jiao S, Fray DJ (2009) Development of an inert anode for electrowinning in calcium chloride-calcium oxide melts. Metall Mater Trans B 41:74–79. https://doi.org/10.1007/s11663-009-9281-8

    Article  CAS  Google Scholar 

  22. Jiao S, Zhang L, Zhu H, Fray DJ (2010) Production of NiTi shape memory alloys via electro-deoxidation utilizing an inert anode. Electrochim Acta 55:7016–7020. https://doi.org/10.1016/j.electacta.2010.06.033

    Article  CAS  Google Scholar 

  23. Hu L, Song Y, Ge J, Jiao S, Cheng J (2016) Electrochemical metallurgy in CaCl2 -CaO melts on the basis of TiO2-RuO2 inert anode. J Electrochem Soc 163:E33–E38. https://doi.org/10.1149/2.0131603jes

    Article  CAS  Google Scholar 

  24. Du Y, Kou M, Tu J, Wang M, Jiao S (2021) An investigation into the anodic behavior of TiB2 in a CaCl2-based molten salt. Corros Sci 178:1–7. https://doi.org/10.1016/j.corsci.2020.109089

    Article  CAS  Google Scholar 

  25. Kvalheim E, Haarberg GM, Martinez AM, Jahren HM (2009) Inert anodes for oxygen evolution in molten salts. ECS Trans 16:367–374. https://doi.org/10.1149/1.3159341

    Article  CAS  Google Scholar 

  26. Burheim O, Haarberg GM (2010) Effects of inert anodes in the FFC Cambridge reduction of hematite. Trans Inst Miner Metall Sect C. https://doi.org/10.1179/037195510X12665949176454

    Article  Google Scholar 

  27. Yin H, Gao L, Zhu H, Mao X, Gan F, Wang D (2011) On the development of metallic inert anode for molten CaCl2-CaO System. Electrochim Acta 56:3296–3302. https://doi.org/10.1016/j.electacta.2011.01.026

    Article  CAS  Google Scholar 

  28. Snook GA, McGregor K, Urban AJ, Lanyon MR, Donelson R, Pownceby MI (2016) Development of a niobium-doped titania inert anode for titanium electrowinning in molten chloride salts. Faraday Discuss 190:35–52. https://doi.org/10.1039/c5fd00235d

    Article  ADS  CAS  PubMed  Google Scholar 

  29. Alzamani M, Jafarzadeh K, Fattah-Alhosseini A (2019) EIS study of oxidation heat-treatment effects on corrosion behavior of Ni10Cu11Fe6Al metallic inert anode inside molten calcium chloride salt. Mater Corros 70:605–611. https://doi.org/10.1002/maco.201810417

    Article  CAS  Google Scholar 

  30. Alzamani M, Jafarzadeh K, Fattah-alhosseini A (2021) Development of lanthanum doped Ni10Cu11Fe6Al as a new inert anode in molten salt calcium chloride for titanium oxide electrolysis. J Alloys Compd 876:159997. https://doi.org/10.1016/j.jallcom.2021.159997

    Article  CAS  Google Scholar 

  31. Choi EY, Lee JW, Park JJ, Hur JM, Kim JK, Jung KY, Jeong SM (2012) Electrochemical reduction behavior of a highly porous SIMFUEL particle in a LiCl molten salt. Chem Eng J 207–208:514–520. https://doi.org/10.1016/J.CEJ.2012.06.161

    Article  Google Scholar 

  32. Choi EY, Jeong SM (2015) Electrochemical processing of spent nuclear fuels: an overview of oxide reduction in pyroprocessing technology. Prog Natl Sci Mater Int 25:572–582. https://doi.org/10.1016/j.pnsc.2015.11.001

    Article  CAS  Google Scholar 

  33. Choi E-Y, Lee J, Heo DH, Lee SK, Jeon MK, Hong SS, Kim S-W, Kang HW, Jeon S-C, Hur J-M (2017) Electrolytic reduction runs of 0.6 kg scale-simulated oxide fuel in a Li2O-LiCl molten salt using metal anode shrouds. J Nucl Mater 489:1–8. https://doi.org/10.1016/j.jnucmat.2017.03.035

    Article  ADS  CAS  Google Scholar 

  34. Iizuka M, Inoue T, Ougier M, Glatz J-P (2007) Electrochemical reduction of (U, Pu)O2 in molten LiCl and CaCl2 electrolytes. J Nucl Sci Technol 44:801–813. https://doi.org/10.1080/18811248.2007.9711869

    Article  CAS  Google Scholar 

  35. Jeong SM, Shin H-S, Cho S-H, Hur J-M, Lee HS (2009) Electrochemical behavior of a platinum anode for reduction of uranium oxide in a LiCl molten salt. Electrochim Acta 54:6335–6340. https://doi.org/10.1016/j.electacta.2009.05.080

    Article  CAS  Google Scholar 

  36. Joseph TB, Sanil N, Shakila L, Mohandas KS, Nagarajan K (2014) A cyclic voltammetry study of the electrochemical behavior of platinum in oxide-ion rich LiCl melts. Electrochim Acta 139:394–400. https://doi.org/10.1016/j.electacta.2014.07.025

    Article  CAS  Google Scholar 

  37. Sakamura Y, Kurata M, Inoue T (2006) Electrochemical reduction of UO2 in molten CaCl2 or LiCl. J Electrochem Soc 153:D31–D31. https://doi.org/10.1149/1.2160430

    Article  CAS  Google Scholar 

  38. Pertuiset J, Gibilaro M, Lemoine O, Chamelot P, Bourges G, Massot L (2023) Electrochemical behavior of gold, palladium and platinum as inert anode materials for molten chloride electrolysis. Electrochim Acta 439:141598. https://doi.org/10.1016/J.ELECTACTA.2022.141598

    Article  CAS  Google Scholar 

  39. Mukherjee A, Kumaresan R, Ghosh S (2021) Redox behaviour of CaCl2 melts in presence of moisture as impurity. Part I: cyclic voltammetry. J Electroanal Chem 902:5778. https://doi.org/10.1016/j.jelechem.2021.115778

    Article  CAS  Google Scholar 

  40. Mukherjee A, Kumaresan R, Ghosh S (2021) Redox behaviour of CaCl2 melts in presence of moisture as impurity. Part II: electrochemical impedance spectroscopy. J Electroanal Chem 901:5710. https://doi.org/10.1016/j.jelechem.2021.115710

    Article  CAS  Google Scholar 

  41. Roine A (2008) HSC Chemistry (Version 5.11), Outokumpu Research Oy, Finland

  42. Bale CW, Bélisle E, Chartrand P, Decterov SA, Eriksson G, Gheribi AE, Hack K, Jung IH, Kang YB, Melançon J, Pelton AD, Petersen S, Robelin C, Sangster J, Spencer P, Van Ende MA (2016) Reprint of: FactSage thermochemical software and databases, 2010–2016. Calphad 55:1–19. https://doi.org/10.1016/J.CALPHAD.2016.07.004

    Article  CAS  Google Scholar 

  43. Sauzet H, Collet R, Héau C, Pupier C, Rodrigues D, Cannes C, Delpech S (2022) Redox properties of the carbonate molten salt Li2CO3-Na2CO3-K2CO3. Electrochim Acta 405:139765. https://doi.org/10.1016/J.ELECTACTA.2021.139765

    Article  CAS  Google Scholar 

  44. Yao B, Xiao Y, Jia Y, Wu S, Yang M, He H (2022) Diffusion behavior of oxygen in the electro-deoxidation of uranium oxide in LiCl-rich melt. J Nucl Mater 562:153582. https://doi.org/10.1016/J.JNUCMAT.2022.153582

    Article  CAS  Google Scholar 

  45. Descallar-Arriesgado RF, Kobayashi N, Kikuchi T, Suzuki RO (2011) Calciothermic reduction of NiO by molten salt electrolysis of CaO in CaCl2 melt. Electrochim Acta 56:8422–8429. https://doi.org/10.1016/j.electacta.2011.07.027

    Article  CAS  Google Scholar 

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Acknowledgements

The authors wish to thank Dr. R. Raja Madhavan for carrying out the XRD analyses and Dr. Pradyumna Kumar Parida and Dr. S. Amirthapandian for recording the SEM images. The authors acknowledge Mrs. Shakila Logu, Mr. V. Arun Kumar and Mr. Mohd. Sufiyan Khan for their help in conducting some of the molten salt experiments.

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Authors and Affiliations

  1. Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu, 603102, India

    Anwesha Mukherjee & R. Kumaresan

  2. Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai, 400094, India

    Anwesha Mukherjee & R. Kumaresan

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  1. Anwesha Mukherjee
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  2. R. Kumaresan
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AM: conceptualization, methodology, formal analysis and investigation, writing–original draft preparation; RK: methodology, formal analysis, supervision, writing—review and editing.

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Correspondence to R. Kumaresan.

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Mukherjee, A., Kumaresan, R. Investigation on the application of platinum anode towards direct electrochemical reduction of solid metal oxides in CaCl2–CaO melt. J Appl Electrochem (2024). https://doi.org/10.1007/s10800-024-02096-x

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