In turn, PXRD patterns of Cu@SiO2-12, Cu@SiO2-15, and Cu@SiO2-16 contained the peaks which could be assigned to Cu2O (2θ = 36.4, 42.3) in addition to the peaks of metallic Cu. These composites were prepared by pyrolysis of complexes obtained from Cu(Ac)2 and Phen with Phen:Cu ratio equal to 2. The same Phen:Cu ratio was used for synthesis of other composites, which did not contain Cu2O. In contrast to the composites, made from CuCl2, in the case of Cu(Ac)2-Phen system there is apparently no relation between "completeess" of Cu II reduction and ligand-to-copper ratio, because different products formed at the same Phen:Cu ratio.