Selective glycerol-to-glycerate electro-oxidation on Cerium-modified Pt/C nanocatalyst in an Alkaline Direct Alcohol Fuel Cell: cogeneration of energy and value-added products

Glycerol electro-oxidation reaction was performed in an alkaline environment with an anion exchange membrane fuel cell (AEMFC) operating in bath mode at low Pt-loadings. BAE-synthesized Pt/C and PtCe/C nanostructured catalysts were used as anode materials during 4-hour operation to selectively obtain 65 % and 41 % of glycerate as main product, respectively. The modification of Pt with Ce improved the catalytic activity of the Pt/C catalyst generating 30 % more energy density after 4-hour operation by achieving a higher degree of glycerol oxidation in cogeneration with added-value products confirmed by spectroelectrochemical (in situ FTIR) and liquid chromatography coupled with mass spectrometry (LC-MS) analyses. The bifunctional mechanism generated by the presence of Ce is used to explain the improvement in the catalytic activity of Pt/C, due to the properties of this rare earth element to adsorb oxygenated species (OH-) and promote oxidation. The cathode material was a polyol-synthesized PdFe/C electro-catalyst for ORR that presented impressive stability and tolerance to glycerol. The glycerol oxidation in a cogeneration process leads to value added products (VAP) on Pt/C or provides more energy on PtCeO2/C in a direct glycerol fuel cell (DGFC).image