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O: Fachverband Oberflächenphysik
O 18: Solid-Liquid Interfaces I: Structure and Spectroscopy
O 18.2: Vortrag
Montag, 18. März 2024, 15:15–15:30, H 1012
Interfacial water structure effects during CO2 electroreduction — •Ya-Wei Zhou1,2, Beatriz Roldan Cuenya2, and Christopher Seiji Kley1,2 — 1Helmholtz Young Investigator Group Nanoscale Operando CO2 Photo-Electrocatalysis, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germany — 2Department of Interface Science, Fritz Haber Institute of the Max Planck Society, 14195 Berlin, Germany
We combine on-line differential electrochemcial mass spectroscopy (DEMS), in situ attenuated total reflection surface enhanced Infrared spectroscopy (ATR-SEIRAS), operando shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) and density functional theory (DFT) to investigate the structure and dynamic process of interfacial water on Au and Cu surfaces during CO2 electroreduction reaction (CO2RR). Direct ATR-SEIRAS evidence and D2O labelling DEMS data reveals that H2O is the proton donor of CO2RR and HER, while bicarbonate is solely involved in the Heyrovsky step. We reveal that hydrated CO32- increases the ordering of the hydration water network, with shorter H-bond leading to rapid delivery of electrons and protons at the electrode-electrolyte interface. This, in turn, suppresses the CO2RR due to promoted H* formation through the increased connectivity of the CO32- induced interfacial water network in the high current density region. We observe a carbonate anion radical (CO3.-) on both Au and Cu surfaces that we propose to originate from hydrated CO32-, acting as additional carbon source under reducing condition.
Keywords: CO2 electroreduction mechanism; In situ ATR-SEIRAS; On line DEMS; Operando SHINERS; Isotopic labelling experiment