Change in reduction products during long term operation of electrochemical CO₂ reduction with Cu electrode and the effect of anodize

Abstract To reduce the concentration of CO 2 in the atmosphere, a great deal of research has been carried out into electrochemical CO 2 reduction technology. The electrochemical CO 2 reduction process has the problem of the insufficient selectivity of the reduced products. Cu catalyst is identified as a potential material of industrially useful substances, including C 2 H 4 and CH 4 . However, the majority of these studies are the products generated during the initial stages of the electrochemical reaction. Accordingly, we used our homemade H-shaped cell and Cu electrodes to conduct electrochemical CO 2 reduction over 500 h, with evaluating products. An anodized Cu electrode was also evaluated over 500 h. The surface structure of the electrode and the products changed significantly over time. Consequently, it is believed that the efficacy of electrochemical CO 2 reduction should be evaluated not only in the short term but also over extended periods.