Title: Electrochemical Behavior of Fe3O4 in NaCl-CaCl2 Melts
Abstract: Abstract The reduction and dissolution mechanism of Fe 3 O 4 in NaCl-CaCl 2 melts system are analyzed by thermodynamics. The electrochemical methods of Fe 3 O 4 in NaCl-CaCl 2 melts are studied by cyclic voltammetry, square wave voltammetry and open-circuit chronopotentiometry. The effects of temperature on reduction potential and peak current are investigated. The diffusion coefficients of Fe 3+ and Fe 2+ at different temperatures are calculated, and the activation energy E is obtained. Electrolytic products are obtained after 10 min of potentiostatic electrolysis in the melts of NaCl-CaCl 2 -Fe 3 O 4 at 1073 K and 1.9 V. The results of XRD show that no other compounds are formed in the melts, indicating that Fe 3 O 4 do not react chemically in the NaCl-CaCl 2 melts system at 973 K, which is consistent with the theoretical analysis. Fe 3 O 4 is reduced by two-step quasi-reversible reaction in the melts of NaCl-CaCl 2 at 973 K to obtain iron: Fe 3+ → Fe 2+ → Fe. The two-step reaction is controlled by diffusion. The diffusion coefficients are 4.53 × 10 –6 cm 2 ·s –1 and 1.17 × 10 –6 cm 2 ·s –1 , respectively. Fe 3 O 4 is reduced in two steps. The potential shifts with temperature and decreases with the increase of the proportion of Fe 3 O 4 . The activation energies of the two-step reaction are 62.38 kJ·mol –1 and 77.52 kJ·mol –1 . A deposited layer of uniform distribution, high coverage and dense iron is prepared.
Publication Year: 2019
Publication Date: 2019-08-06
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 6
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