Abstract:
The solid-liquid interfacial reactions play a crucial role in controlling the performance and stability of electrocatalysts and battery materials [1-6]. In situ spectroscopy techniques such as X-ray absorption spectroscopy (XAS) and surface-enhanced infrared absorption spectroscopy (SEIRAS) are the powerful tools for examining the surface-adsorbed intermediates on the solid-liquid interfaces. In this talk, we report on our use of in situ SEIRAS, Raman, and XAS to investigate the electrochemical CO2 reduction mechanism over the Cu-based electrocatalysts and the reaction mechanism of Li-rich layered oxide cathode in Li-ion/Li metal batteries [4-5]. For instance, Cu-based electrodes with different oxidation states result in the formation of various CO intermediates such as COatop and CObridge during electrochemical CO2 reduction reaction. The co-existence of COatop and CObridge corresponds to the selectivity of CO2-to-C2H4 reaction. Also, the bimetallic electrocatalysts are developed for efficient CO2-to-HCOOH and CO2-to-CO conversion processes. We found that the surface-adsorbed COO species with different binding structures play crucial role in the reduction process. The electronic structures of Cu-based electrocatalysts are associated with the formation of surface-adsorbed intermediates and electrocatalytic properties. The formation of surface-adsorbed intermediates and reaction mechanism associated with CO2-to-HCOOH and CO2-to-CO reactions over the bimetallic electrocatalysts will be discussed in detail.
References
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Keywords – solid-liquid interfacial reactions, infrared absorption spectroscopy, X-ray absorption spectroscopy, electrocatalysts, battery materials