The thermochemical copper-chlorine (Cu-Cl) cycle is a promising method for the production of hydrogen and oxygen. It consists of four steps: chlorination, disproportionation, oxychlorination, and decomposition. In this study, we focused on the last two steps. A novel dispersion of CuCl2 nanoparticles (similar to 90 nm) in activated carbon rnicrofibers (ACFs) was prepared and used for the production of oxygen through the oxychlorination of CuCl2 with steam, which was followed by the decomposition of the oxychlorinated product. The CuCl2-ACFs were prepared using the wet incipience impregnation method. After calcination of the impregnated ACF, CuCl2 nanoparticles were produced in situ on the ACF. The production rate of O-2 was found to be 2.7 x 10(-6) mol/g.s, which is significantly higher than the data reported in the literature. The CuCl2-ACFs prepared in this study are a potential candidate for the O-2 production step of the thermochemical Cu-Cl cycle.