Fundamental studies in the field of electrochemistry at the level of single nanoparticles using synchrotron-based techniques

• Grant number: 21/02678-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): August 01, 2021
• Effective date (End): July 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Pablo Sebastián Fernández
• Grantee: Rafael Alcides Vicente
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Host Company: Universidade Estadual de Campinas (UNICAMP). Instituto de Química (IQ)
• Associated research grant: 17/11986-5 - Research Division 1 - Dense Energy Carriers, AP.PCPE

Abstract

Electrochemistry is an extremely impactful field, which affects several segments in Economy, Science, and Technology. Electrocatalysis is particularly relevant due to its presence in industrial and environmental applications, energy storage and production. In this context, nanomaterials represent a major class of electrode materials employed in electrocatalysis. Thus, the development of several important electrocatalytic systems relies on understanding the mechanisms of reactions catalyzed by nanoparticles. The measured electrocatalytic response of an electrode made by nanoparticles is a consequence of the signals coming from the many particles that compose the electrode. Since the electrochemical performance is dependent on the composition and morphology of the particles, and a real electrode contains particles with a range of compositions and morphology, it is difficult to connect these parameters with performance using conventional techniques. Thus, we propose to develop instrumentation to perform in situ electrochemistry measurements of single nanoparticles, exploiting a fourth-generation synchrotron radiation facility (SIRIUS) and then use these tools to revisit some "well-known" systems previously studied in the conventional way, i.e., not investigated at the single nanoparticle level. The oxidation state and local structure will be determined by X-ray absorption measurements. In addition, BCDI (Bragg Coherent Diffraction Imaging) will be used to image changes in the nanoparticle morphology and observe the strain map (in 3D), a parameter that can strongly influence the electrocatalytic behavior of materials.We will prepare shape-controlled Pt, Pd and Au nanoparticles and follow the parameters mentioned before during: I) the electrochemical cycling (stability study); II) the adsorption and electrooxidation of CO; III) the adsorption and absorption (in Pd) of hydrogen and VI) the deposition of Cu and Pb on the noble metals.It is worth noting that this complex set of synchrotron techniques, and the specific instrumentation to be developed, will be available in the Carnaúba beamline to be applied in any study in the field of electrochemistry for future external users. Thus, the achievements of this project will contribute to the large community of future users of this beamline. (AU)