SFG Evaluation of Emerging Interfacial Features During Electro-Oxidation of Ethanol in Seawater-Like Electrolytes

• Grant number: 24/12366-4
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: October 01, 2024
• End date: September 30, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Hamilton Brandão Varela de Albuquerque
• Grantee: Thiago Vasconcelos de Barros Ferraz
• Supervisor: Yujin Tong
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Institution abroad: University of Duisburg-Essen, Germany
• Associated to the scholarship: 21/13002-8 - Study of the electrooxidation of small organic molecules in saline solutions for the simultaneous valorization of biomass and CO2 mittigation, BP.DR

Abstract

Recently, the combination of ethanol with seawater has been investigated not only from the bioremediation side but also for its potential in providing eco-friendly and economically beneficial processes. From an electrochemical perspective, ethanol electro-oxidation in natural saline waters may offer solutions to logistical challenges in CO2 mitigation strategies, such as accelerated weathering of limestone. Nevertheless, this approach faces efficiency limitations due to the strong adsorption of chloride ions, naturally present in seawater, on most metallic catalysts. To address these limitations, various strategies have been proposed, such as modifying the bulk and interfacial properties of the catalytic substrate. However, these methods are often lacking in sufficiently explaining how the composition of the reaction medium influences selectivity and energetic efficiency in electrochemical reforming processes. Considering the exposed, the goal of this international internship project is to use in situ sum-frequency generation (SFG), an inherently interface-specific second-order non-linear optical process, in spectroelectrochemical measurements to study interfacial features of interest that arise during ethanol electro-oxidation on a model polycrystalline platinum electrode in seawater-like solutions. By adjusting the pH and composition of the said solutions, we aim to understand the phenomenological causes of these electrode/electrolyte frontier effects, both within and beyond thermodynamic equilibrium. This project combines the complementary expertise of the hosting Campen/Tong Group in nonlinear spectroscopy at the University of Duisburg-Essen (Duisburg, Germany) and the Electrochemistry Group in electrocatalysis and fundamental electrochemistry at the University of São Paulo (São Carlos, Brazil), where the associated doctoral research has been developed.