KSEA events Operando X-ray absorption spectroscopy studies on CO electroreduction reaction (200124 KSEA Berkeley Chapter Seminar)
TITLE: Operando X-ray absorption spectroscopy studies on CO electroreduction reaction
SPEAKER: Dr. Soo Hong Lee
ABSTRACT: The rational design of high-performance electrocatalysts requires a detailed understanding of structural features under realistic working conditions. Oxide-derived Cu catalysts exhibit a remarkable selectivity towards multi-carbon products for the electrochemical CO reduction reaction (CORR), but the exact role of oxide remains elusive for explaining the performance enhancements. Here, we used operando X-ray absorption spectroscopy coupled with gas chromatography and electrochemical double-layer capacitance (EDLC) measurements to show that the ethylene (C2H4) production is not correlated with oxidation state or electrochemical surface area of the catalyst under high current densities. In the gas-diffusion electrodes, the increased C2H4 activity and selectivity were related to the morphological transformation that originates from the in-situ electroreduction of the oxide structure at the early stage of the reaction. These results give rise to an electrochemical regeneration method that restores the original catalyst performances without cell disassembly. Our study establishes a basis for the rational design of highly active electrocatalysts for broad-range reactions in the gas-fed device.
BIO: Dr. Soo Hong Lee is a PostDoc working with Dr. Walter S. Drisdell in Joint center for artificial photosynthesis (JCAP), Chemical Science Division of LBNL. He received Ph.D. and B.S. in Chemical engineering at Seoul National University, South Korea. He is now working on operando X-ray studies for CO2 and CO electroreduction reaction.