Mono- or binuclear copper homogeneous catalysts with similar coordination environments were used for benzene hydroxylation. The effect of multiple active sites on phenol formation was investigated. The structures of the synthesized mono- and binuclear copper catalysts were confirmed by FT-IR and EXAFS. Molecular oxygen was used as the oxidant and it was found that the binuclear copper catalyst showed better phenols formation than the mononuclear catalyst.