Nanoscale characterization of bimetallic electrodes by in situ electrochemical Tip-enhanced Raman spectroscopy (EC-TERS)

• Grant number: 22/16286-0
• Support Opportunities: Scholarships abroad - Research
• Start date: March 27, 2023
• End date: December 11, 2023
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Ana Maria Gómez Marín
• Grantee: Ana Maria Gómez Marín
• Host Investigator: Katrin F. Domke
• Host Institution: Divisão de Ciências Fundamentais (IEF). Instituto Tecnológico de Aeronáutica (ITA). Ministério da Defesa (Brasil). São José dos Campos , SP, Brazil
• Institution abroad: Max Planck Society, Mainz, Germany

Abstract

The quest for identification of surface intermediate species and active sites, or composition and structure of actives centers for a given reaction is among the most challenging issues in heterogeneous catalysis. In electrochemical environments this point is even more intricate to tackle because of the additional phenomena at electrified interfaces. This information is keystone for a rational approach in the design of novel catalytic materials that would allow tailoring specific active sites or architectures from fundamental principles. One of the main obstacles to achieving this goal is partially due to the lack of appropriate methodologies to acquire in-situ atomic scale information. Tip-enhanced Raman spectroscopy (TERS), a combination of Scanning Probe Microscopy and enhanced Raman scattering, has emerged as a powerful alternative to correlate activity and specific surface structures of heterogeneous catalysts, as it simultaneously provides spatial resolution and Raman fingerprint information. This project aims to assess the suitability of using TERS under the electrochemical environment (EC-TERS) to characterize the interfacial properties and reactivity of hydrogen and CO adlayers toward hydrogen evolution and CO oxidation under operando conditions on catalytically relevant bimetallic systems, topographically close to practical catalytic materials, such as Pd/Au and Pt/Au. Understanding the electronic properties of specific atomic surface sites in these systems is particularly important in the field of electrochemical systems for clean energy conversion/storage. (AU)