Table 3.

Reaction characteristics of Cu–Cl cycle [11,85].

Reaction name	Reactions	Temperature (K)
Electrolysis of CuCl and HCl	2CuCl(aq) + 2HCl(aq) $\to$ H2(g) + 2CuCl2(aq)	298
Hydrolysis of CuCl2	2CuCl2(s) + H2O(g) $\to$ Cu2OCl2(s) + 2HCl(g)	298–648
Thermolysis of Cu2OCl2	Cu2Ocl2(s) $\to$ 2CuCl(l) + ½ O2(g)	648–803

(aq: aqueous; g: gaseous; s: solid; l: liquid; while aqueous solution appears in liquid form, the liquid subscript represents a molten state of the salt instead of aqueous; drying process: CuCl₂(aq) $\to$ CuCl₂(s) T = 308–353 K.).