122nd General Meeting of the KCS

Type Poster Presentation
Area Electrochemistry
Room No. Grand Ballroom
Time 10월 19일 (금요일) 11:00~12:30
Code ELEC.P-470
Subject Electrocatalytic CO2 Conversion to CO on Gold Nanoclusters in a Flow Electrolyzer
Authors Hoeun Seong, Yongjin Lee, Dongil Lee*
Department of Chemistry, Yonsei University, Korea
Abstract Electrochemical reduction of CO2 is a promising technology to mitigate CO2 emissions and store intermittent renewable energy. Among the electrocatalysts for CO2 reduction, Au based materials are reported to show the highest activity and selectivity, but polycrystalline Au electrodes still suffer from discontented selectivity, catalytic rates, and rather high overpotential. In this poster, we present that atomically precise ligand protected gold nanoclusters, such as Au25(SR)18, where SR is thiolate ligand, can effectively and selectively convert CO2 to CO. The CO2 electroreduction was studied with Au25(SR)18 nanoclusters immobilized on carbon-based gas diffusion electrode under various pH conditions in a flow electrolyzer. We found that Au25(SR)18 nanoclusters can convert CO2 to CO with high selectivity (>90%) with high current density over 300mA cm-2 under 3M KOH. In terms of cell potential, we achieve ~1.6V of cell onset potential (lηcelll = ~0.3V), with Au25 nanoclusters as cathode catalysts and IrO2 as anode catalysts. Additionally, we found that electrolyte plays a key role in catalytic activity of Au nanoclusters. Electrocatalytic rates of Au nanoclusters were higher under KOH solution rather than under KCl solution that has same molarity. Moreover, with increase of KOH concentration, higher jCO (CO partial current densities) values are observed, maintaining selectivity for CO over 90%.
E-mail she6023@gmail.com