Towards a general understanding of the effect of p-block adatoms on the electrooxidation of polyols on platinum in alkaline media

Abstract

The depletion of fossil fuels and environmental concerns are speeding up the transition to a bio-based economy. Thus, several polyols were pointed out as alternative for the generation of value-added molecules and energy. Glycerol is a biofuel that can be used as a feedstock for several value-added products. Besides, this is the simplest polyol containing a primary and secondary carbon turning this molecule an interesting candidate to be used as a model for the study of the electrooxidation of polyols (EOP). The EOP has been studied mainly in acid media and in Pt-based electrodes. The modification of Pt with p-block adatoms is an interesting strategy to tune both, the electrode activity and reaction selectivity.Pt electrodes are one order of magnitude more active in alkaline media, however the EOP has been less studied in this condition and the details of the reactions are not well-understood. Recently submitted results have shown that Bi and Pb adatoms also promotes the electrooxidation of glycerol (EOG) and that the activity enhancement is higher than in acid media.Thus, in this project, we aim to understand the effect of p-block adatoms on the EOG on Pt in alkaline media at the atomic-level. We will modify Pt electrodes with several p-block atoms, study the reaction selectivity and catalyst activity as a function of the electrode coverage and finally identify the key parameters influencing the reaction.FTIR and RAMAN in situ, Fraction collection on line (coupled to HPLC and NMR), X-rays absorption (using synchrotron radiation) and Mass Spectrometry on line will permit to investigate electronic and structural changes on the surface of the modified Pt catalyst and at the same time to monitor the generation of intermediates and products of the EOG. Besides, Density Functional Theory experiments will help us to understand the electrochemical results in terms of atomic properties (intermediates structure, adsorption energies, etc.). (AU)