RUI: Reductive Activation of Carbon Dioxide by Binuclear Copper Complexes with a Copper-Copper Unit

University Of Central Arkansas, Conway AR

Investigators

Abstract

Dr. Lei Yang at the University of Central Arkansas is leading a program aimed at converting carbon dioxide into useful chemicals. This theme is attractive because carbon dioxide is abundant. To accelerate the reactions of carbon dioxide, metal-based catalysts are often used. The way by which these catalysts operate is still not well understood, which slows commercial applications. To address this gap, detailed studies are required for known catalysts to understand how they operation. This will help in the design of new catalysts. Dr. Yang's project emphasizes both directions - building understanding and new design. In this project, Dr. Yang's group is making special ligands that hold pairs of copper atoms together. Preliminary tests show that these di-copper catalysts are promising for conversions of carbon dioxide. These activities are well suited for training students. Under the guidance of Dr. Yang, undergraduate students gain hands-on experience in both organic and inorganic chemistry. Additionally, students receive training with state-of-the-art instrumentation. This training is designed to spark their interest in technology careers. This project is jointly funded by CHE and the Established Program to Stimulate Competitive Research (EPSCoR). To convert carbon dioxide (CO2) to value-added chemicals for industry, Dr. Lei Yang's group at the University of Central Arkansas is focusing on the development of new binuclear copper catalysts featuring pairs of CuI centers. The metals are held in close proximity by special binucleating ligands that enforce close Cu-Cu interaction. The functions of the Cu-Cu unit are to reduce CO2 in a cooperative fashion through one electron transfer process and to stabilize the reduction intermediates and products. The distinctive ligand design promises high catalytic efficiency and product selectivity. The structures of the catalysts are characterized by X-ray crystallography. Additional spectroscopic characterization is provided by ultraviolet-visible (UV-vis), Fourier-transform infrared (FT-IR), electron paramagnetic resonance (EPR), and X-ray photoelectron (XPS) spectroscopies. The goal is to obtain fundamental insights into the mechanisms of CO2 reduction. Density functional theory (DFT) computational studies are conducted to predict intermediate structures and interpret spectroscopic data. Dr. Yang supervises undergraduate students in this research program to enhance their understanding of chemical sciences and improve their experimental and teamwork skills. This project serves as a way to inspire and prepare students for successful careers in STEM fields. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.