Anodized Zn electrode for formate selectivity during the electrochemical reduction of CO2 at low applied potential

Abstract

It is well known that the main product of the CO2 electrochemical reduction on zinc electrodes is CO. In this study, it was observed that an anodized Zn electrode can produce formate with high selectivity during the electrochemical reduction of CO2 at low applied potentials. The Zn electrode obtained using a simple anodization method produced formate with a Faradaic efficiency of more than 60% via reduction of CO2 at a low potential of −1.19 V vs. the reversible hydrogen electrode (RHE). According to several previous studies, selectivity toward formate production requires a large potential of approximately −2.0 V vs. RHE. X-ray diffraction analysis of this electrode suggests that the surface of this electrode is dominated by the Zn (101) plane and that Zn (101) is highly active in formate formation. This study confirms that an anodized Zn (101) facet can generate formate during CO2 electrochemical reduction at a low applied potential.

Keywords

• CO2 reduction
• Zinc
• Formate
• Production selectivity