CoPt Nanowires with Low Pt Content for the Catalytic Methanol Oxidation Reaction (MOR)

CoPt nanowires with low Pt content and optimized catalytic properties for the methanol oxidation reaction (MOR) are synthetized by electrodeposition, and their morphology and composition are investigated. By controlling the synthesis conditions, an increase in the Co concentration from 7% up to 90% is achieved, thus leading to a reduced Pt content. Saccharine was used to control the crystalline structure of the CoPt nanowires. X-ray diffraction investigations revealed that the face-centered cubic crystalline structure transforms into the hcp crystalline structure when saccharine is added into the electrochemical bath. The electrocatalytic performance of CoPt nanowires increases even though the Pt content in the samples decreases due to the change in the crystalline structure. A dramatic increase in the catalytic activity is obtained, from 10 to 85 mA cm⁻² (almost two times higher than the best value reported in the literature on CoPt nanoparticles), making these nanowires the best catalyst candidates for the MOR.