Enhanced Alcohol Electrochemical Oxidation by Using an Environmentally Friendly Xanthan Gum Binder

A sugar-derived green biopolymer, xanthan gum, can replacethe universal but toxic binder nafion for electrocatalytic alcoholoxidations due to its hydrophilicity and homogeneous adhesion of catalystsonto the electrode. Inelectrocatalytic processes, the intimate contact between thecatalyst and the electrode is of paramount importance as it contributesto enhancing the catalytic activity. Nafion is a binding materialfrequently used to achieve this goal. However, its high price, hightoxicity, and flammability make its application expensive and environmentallyunfriendly. Here we show that xanthan gum (XG), a sugar-derived biopolymer,is a greater alternative and furthermore remarkably improves the electrocatalyticoxidation activity of alcohols and sugars in alkaline electrolytes.The even distribution of the catalyst-XG film on the electrode'ssurface and its better mechanical properties drive an intimate contactbetween the catalyst and the electrode, hence facilitating the electrontransfer. In addition, we found that the good hydrophilicity of XGfilms facilitates the interaction of alcohols and hydroxides withthe catalyst, which was supported by DFT calculations. This findingis of crucial importance for industrial applications and environmentalconsiderations. Indeed, the utilization of XG drastically minimizesthe cost of electrochemical processes by using less catalyst and dueto its nature contributes to protecting the environment.