This study investigates Cu(II) complexes of cyclam, propylene cross-bridged cyclam (PCB-cyclam), and propylene crossbridged cyclam diacetate (PCB-TE2A) as homogeneous electrocatalysts for CO 2 reduction in comparison with Ni(II)-cyclam. It is found that Cu(II)-cyclam can catalyze CO 2 reduction at the potential close to its thermodynamic value (0.75 V vs. Ag/AgCl) in tris-HCl buffer (pH 8.45) on a glassy carbon electrode. Cu(II)-cyclam, however, suffers from severe demetalation due to the insufficient stability of Cu(I)-cyclam. Cu(II)-PCB-cyclam and Cu(II)-PCB-TE2A are revealed to exhibit much less demetalation behavior, but poor CO 2 reduction activities as well. The inferior electrocatalytic ability of Cu(II)-PCB-cyclam is ascribed to its redox potential that is too high for CO 2 reduction, and that of Cu(II)-PCB-TE2A to the steric hindrance preventing facile contact with CO 2 molecules. This study suggests that in addition to the redox potential and chemical stability, the stereochemical aspect has to be considered in designing efficient electrocatalysts for CO 2 reduction.