Electrodeposition of iron(II) on platinum in chloride melts at 700–750°C

Electrochemical Behaviour of Dissolved Iron Chloride in KCl+LiCl+NaCl Melt at 550ºC

“…However, it showed to be not very stable and was difficult to detect it [6,7,10]. But in some other studies iron (III) chloride was not detected at all [12,13,15,16]. Its absence has been attributed to instability/volatility of this compound [6].…”

“…In many studies, Fe (II) ions were generated by anodic dissolution of metallic iron at constant current (coulometry) [14,10]. On the other hand, it has been reported that the addition of anhydrous FeCl 3 leads to generation of stable Fe (III) ions [18] while other papers have shown that FeCl 3 .6H 2 O can serve as a source of bivalent iron [12][13]. In those two cases, where FeCl 3 was added to the melt [11,18], the reduction occurred in one single reversible step; Fe (III)/Fe (0).…”

“…Platinum has shown high reactivity towards iron ions; when it is used as substrate, alloying occurs and the Fe (II) reduction is far from reversible [6,12,16]. Other substrates such as tungsten, glassy carbon and molybdenum have shown inertness towards iron ions [6,11,[13][14][15][16][17] with one exception for tungsten [18].…”

“…This reaction may be catalysed by the electrode surface [6]. In addition, the electrode itself may participate in electrochemical reactions by alloying with iron and complicating reactions [12] or through oxidation and chemically reducing Fe (III) ions; the latter conceals electrochemical oxidation of Fe (II) to Fe (III) [20]. Composition of the melt also has an important effect [21].…”

“…These studies have been performed using different salt mixtures and substrate materials at different temperatures. Some of these electrolytes include KCl+LiCl [6][7][8][9][10], NaCl+KCl [11][12][13], ZnCl 2 +2NaCl [14,15], MgCl 2 +NaCl+KCl [16], AlCl 3 +NaCl [17], and NaCl [18].…”