Decoration of copper foam with Ni nanorods and copper oxide nanosheets to produce a high-stability electrocatalyst for the reduction of CO2: Characterization of the electrosynthesis of isonicotinic acid

Publication date: Available online 4 November 2019Source: Comptes Rendus ChimieAuthor(s): Safoora Mohammadzadeh, Hamid R. Zare, Hossein KhoshroAbstractCuO–Cu2O (CuxO) nanosheets were coated on a copper foam substrate by the electrochemical anodization method in an alkaline solution. Constant current coulometry was performed to electrodeposit Ni nanorods on the surface of a Cu/CuxO electrode. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) proved that the copper oxide nanosheets were anchored on the copper foam substrate and modified by Ni nanorods (Cu/CuxO/Ni). The process took place via a facile and inexpensive electrodeposition method. As the results indicate, owing to the synergistic effect of adjacent CuxO and Ni sites, a Cu/CuxO/Ni electrode has a very good and stable electrocatalytic activity to reduce CO2. As tested in this study, the product of the electrocatalytic reduction of CO2 (i.e. activated CO2, or CO2•−) can be used for the electrocarboxylation of pyridine in mild conditions. Once an electron is transferred from CO2•− to pyridine, a pyridine radical anion is formed. Based on the EC'C′CC mechanism, this radical anion reacts with CO2•− and produces isonicotinic acid as the main product. In addition, two pyridine radical anions react together and produce a 4,4′-bipyridine dimer. The high stability of the electrocatalyst during the electrolysis process and the simplicity of the workup make the proposed modified electrode appropriat...
Source: Comptes Rendus Chimie - Category: Chemistry Source Type: research