Polyols electro-oxidation on controlled Pt surfaces

• Grant number: 14/24029-0
• Support Opportunities: Scholarships abroad - Research
• Start date: July 20, 2015
• End date: February 27, 2016
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Pablo Sebastián Fernández
• Grantee: Pablo Sebastián Fernández
• Host Investigator: Marc Koper
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: Universiteit Leiden, Netherlands

Abstract

The depletion of energy resources and the necessity for efficient and green technologies for the utilization of renewable resources such as biomass has become a hot topic in recent years. Thus, biomass derived polyols such as Glycerol (GlOH), Sorbitol, Arabitol and Xylitol were chosen from the twelve strategic chemicals to be used as building blocks for the fine chemicals production. In this context, the electrochemical applications arise as interesting options for obtaining energy and fine chemicals through these polyols oxidation.The polyols electrooxidation mechanisms (PEOM) have been studied by using electrochemical and spectroscopic techniques. However, there is a lack of knowledge about the oxidation mechanism for most of the small organic molecules (Ethanol, Ethylene glycol, etc.) and a complete lack of awareness for the case of GlOH or bigger polyols.Therefore, there is a necessity for great effort in synthesizing more efficient catalysts with the following characteristics: 1) Polyols efficient oxidation to CO2 (Fuel Cells technology) and 2) Selective oxidation at low electrode potentials to value added chemicals with co-generation of high purity H2 (Electrolyzers).Taking into account the intrinsic complexity of polycrystalline surfaces, (which have a myriad of non-equivalent reaction sites that interact in a different manner with a given reactant or intermediate) in this work we will perform mechanistic studies on Pt model surfaces (single crystals) with different defects degree. The reaction pathways will be investigated by using in situ Fourier Transform Infra-red Spectroscopy, Differential on line Mass Spectrometry and High-Performance Liquid Chromatography (HPLC). All the cited techniques will monitor the intermediates, products or both, formed during a given electrochemical experiment (Cyclic voltammetry or Cronoamperometry). This kind of research, together with theoretical calculations performed by using the Density Functional Theory, will permit a deeper understanding of how the PEOM depends on both the Pt surface structure and the relative molecular structure of the diastereomers and enantiomers used in this work. Finally this work will render a more general understanding of the electrochemical behavior of these kinds of industrially valuable molecules.Lastly, this interaction with the Koper`s Group will help develop the Campinas Electrochemistry Group, which is intended to be a new multidisciplinary group with a important capacity for the electrochemical reaction mechanism study.