Copper complexes with water-insoluble ligands as electrocatalysts for carbon dioxide reduction: characterization of the active sites

• Grant number: 23/11453-8
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: December 11, 2023
• End date: June 20, 2024
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Fabio Henrique Barros de Lima
• Grantee: Rafael Luiz Romano
• Supervisor: Kotaro Sasaki
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Institution abroad: Brookhaven National Laboratory, United States
• Associated to the scholarship: 21/03263-9 - Electrochemical CO2 reduction to C1 and C2 products on catalysts made up of copper complexes with potential dynamic behavior between Cu2-ligand and metallic Cu, BP.DR

Abstract

The electrochemical reduction of carbon dioxide (CO2R) constitutes a promising process that can both contribute to reduce net CO2 emissions and be an alternative/sustainable method to produce valuable chemicals. However, the use of CO2R in large scale is hampered by the high required overpotentials and poor selectivity. Thus, efforts have been made towards the development of more active, selective and stable electrocatalysts for CO2R. Due to the unique ability of copper to promote the electrochemical reduction of CO2 to hydrocarbons and alcohols, several copper-based electrocatalysts have been studied during the past few decades. It was shown that many copper complexes undergo restructuring processes during CO2R, affecting activity and selectivity during operation. Besides, there are some important evidences concerning reversible restructuring, which can be an interesting approach to reach higher stability. In this context, in-situ characterization techniques were shown to be extremely important to investigate the restructuring behavior of the electrocatalysts and to identify the real active sites for CO2R. In this project, the objective is to characterize the active sites of copper-based electrocatalysts (copper complexes) used for CO2R by in-situ X-ray Absorption Spectroscopy and ex-situ High Resolution Transmission Electron Microscopy. Particularly, we aim to investigate the dynamic behavior of copper complexes by identifying and characterizing the active sites formed in-situ under different electrochemical conditions and then correlate the obtained structures to the observed catalytic performance. (AU)