Operando High-Energy-Resolution X-ray Spectroscopy of Evolving Cu Nanoparticle Electrocatalysts for CO 2 Reduction.

Autor:	Feijóo J; Department of Chemistry, University of California, Berkeley, California 94720, United States.; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States., Yang Y; Department of Chemistry, University of California, Berkeley, California 94720, United States.; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.; Miller Institute for Basic Research in Science, University of California, Berkeley, California 94720, United States., Fonseca Guzman MV; Department of Chemistry, University of California, Berkeley, California 94720, United States.; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States., Vargas A; Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States., Chen C; Department of Chemistry, University of California, Berkeley, California 94720, United States.; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States., Pollock CJ; Cornell High Energy Synchrotron Source, Cornell University, Ithaca, New York 14853, United States., Yang P; Department of Chemistry, University of California, Berkeley, California 94720, United States.; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.; Department of Materials Science and Engineering, University of California, Berkeley, California 94720, United States.; Kavli Energy NanoScience Institute, Berkeley, California 94720, United States.
Jazyk:	angličtina
Zdroj:	Journal of the American Chemical Society [J Am Chem Soc] 2023 Sep 20; Vol. 145 (37), pp. 20208-20213. Date of Electronic Publication: 2023 Sep 07.
DOI:	10.1021/jacs.3c08182
Abstrakt:	Advances in electrocatalysis research rely heavily on building a thorough mechanistic understanding of catalyst active sites under realistic operating conditions. Only recently have techniques emerged that enable sensitive spectroscopic data collection to distinguish catalytically relevant surface sites from the underlying bulk material under applied potential in the presence of an electrolyte layer. Here, we demonstrate that operando high-energy-resolution fluorescence detected X-ray absorption spectroscopy (HERFD-XAS) is a powerful spectroscopic method which offers critical surface chemistry insights in CO 2 electroreduction with sub-electronvolt energy resolution using hard X-rays. Combined with the high surface area-to-volume ratio of 5 nm copper nanoparticles, operando HERFD-XAS allows us to observe with clear evidence the breaking of chemical bonds between the ligands and the Cu surface as part of the ligand desorption process occurring under electrochemical potentials relevant for the CO 2 reduction reaction (CO 2 RR). In addition, the dynamic evolution of oxidation state and coordination number throughout the operation of the nanocatalyst was continuously tracked. With these results in hand, undercoordinated metallic copper nanograins are proposed to be the real active sites in the CO 2 RR. This work emphasizes the importance of HERFD-XAS compared to routine XAS in catalyst characterization and mechanism exploration, especially in the complicated electrochemical CO 2 RR.
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu