Electrochemical reduction modeling of copper oxides obtained during in situ and ex situ conditions in the presence of acetic acid

We used the potentiodynamic reduction technique to study the mechanism of copper oxide formation in the presence of acetic acid. We performed all reductions under neutral conditions (0.1 M KCl) until hydrogen evolution. We produced the copper oxides in an environment containing 0, 500, and 800 ppb acetic acid at high relative humidity. We then compared experimental results between electrochemically produced oxide films obtained by imposing anodic potentials to copper specimens in several concentrations of pure acetic acid (1, 0.1, 0.01 and 0.001 M). We found that, as the concentration of the acid decreases, the formation of the copper oxide (I) increases. We also found the same peaks in samples produced under the synthetic environment. We modeled the curves, taking into account the electrochemical reduction of copper (II) oxide (CuO), amorphous cuprite (Cu2O)(am), intermediate cuprite (Cu2O)(in), crystalline cuprite (Cu2O)(cr), and hydrogen. These oxides have been previously detected in similar conditions. We found no evidence of copper carboxylate founding samples produced by the electrochemical method. (C) 2009 Elsevier Ltd. All rights reserved.