Biomass Derived Carbon as Electrocatalyst Support for Ethanol Oxidation Reaction in Alkaline Medium: Electrochemical and Spectroelectrochemical Characterization

Abstract

In the present work, an activated biocarbon (aBC) was studied as a support in Pd electrocatalyst for ethanol oxidation reaction (EOR) in alkaline medium. Pd/aBC sample was compared with a commercial Vulcan carbon supported Pd electrocatalyst. The Pd particles morphology were influenced by the high content of oxygenated surface functional groups of aBC support, which can be relevant for the synthesis of Pd based electrocatalysts, because the Pd particles formation mechanism involves the adsorption of Pd2+ on negative charged sites of aBC support. This adsorption occurs preferentially on electron donor sites such as oxygenated functional groups. Therefore, the higher concentration of these groups in aBC surface can determine a higher concentration of initial nuclei sites for Pd particles formation contributing to the particles agglomeration on aBC support, compromising the Pd/aBC electrocatalytic performance. For both prepared electrocatalysts, the spectroelectrochemical analysis demonstrates that the acetate ion is the main product of the EOR in the alkaline medium.