XAS of Transition Metal Chalcogenides as CO2 Reduction Catalysts and Battery Cathode Materials

Various negative emissions and storage technologies are at the forefront of research in combating climate change. Catalysts and battery materials are pivotal components of these technologies, utilizing electrochemical processes to facilitate energy conversion and storage; In that respect, transition metal chalcogenides (TMCs) have emerged as a promising class of materials with broad applications in catalysis and energy storage. However, understanding the underlying chemical and electronic states responsible for their activity is still lacking. These key states can be probed at both metals and ligand centers using synchrotron-based X-ray absorption spectroscopy (XAS). This thesis focuses on our recent studies using in-situ/operando XAS approaches to understand electrocatalytic CO2 reduction in TMC electrocatalyst, and insights from ligand K-edge and development of in-situ/operando cell for high-throughput measurements. Through ex-situ XAS, we explored mechanisms governing the anionic redox in TMC cathode materials by correlating the changes in the spectra with the structural and electrochemical properties.