The Role of Carbon on Copper–Carbon Composites for the Electrooxidation of Alcohols in an Alkaline Medium

Abstract

Copper–carbon composites were prepared following various different synthetic routes and using various carbon precursors (i.e., lignocellulose and graphite oxide), and were used as electrocatalysts for the oxidation of propargyl alcohol (PGA) in an alkaline medium. The electrochemical response of the copper-based catalysts was analyzed in terms of the influence of the metallic species, the carbon matrix incorporated in the composites, and the chemical structure of the ionomers—Nafion and poly (4-vinylpyridine) cross-linked methyl chloride quaternary salt resin (4VP)—used in the fabrication of the electrodes. Data has shown that the incorporation of reduced graphene oxide sheets between the copper metallic particles increased the performance due to the increased conductivity provided by the carbonaceous phase. Catalytic inks with ca. 40 wt.% Nafion and 12 wt.% 4VP as ionomers provided the best electrochemical response and cohesion of the catalysts, minimizing the losses in the electroactivity of the copper species.