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Structure of the catalytically active copper–ceria interfacial perimeter

Chen, Aling; Yu, Xiaojuan; Zhou, Yan; Miao, Shu; Li, Yong; Kuld, Sebastian; Sehested, Jens; Liu, Jingyue; Aoki, Toshihiro; Hong, Song; Camellone, Matteo Farnesi; Fabris, Stefano; Ning, Jing; Jin, Chuanchuan; Yang, Chengwu; Nefedov, Alexei; Wöll, Christof; Wang, Yuemin; Shen, Wenjie

Abstract (englisch):
Cu/CeO2 catalysts are highly active for the low-temperature water–gas shift—a core reaction in syngas chemistry for tuning the H2/CO/CO2 proportions in feed streams—but the direct identification and quantitative description of the active sites remain challenging. Here we report that the active copper clusters consist of a bottom layer of mainly Cu+ atoms bonded on the oxygen vacancies (Ov) of ceria, in a form of Cu+–Ov–Ce3+, and a top layer of Cu0 atoms coordinated with the underlying Cu+ atoms. This atomic structure model is based on directly observing copper clusters dispersed on ceria by a combination of scanning transmission electron microscopy and electron energy loss spectroscopy, in situ probing of the interfacial copper–ceria bonding environment by infrared spectroscopy and rationalization by density functional theory calculations. These results, together with reaction kinetics, reveal that the reaction occurs at the copper–ceria interfacial perimeter via a site cooperation mechanism: the Cu+ site chemically adsorbs CO whereas the neighbouring Ov–Ce3+ site dissociatively activates H2O.

DOI: 10.1038/s41929-019-0226-6
Zitationen: 2
Zugehörige Institution(en) am KIT Institut für Funktionelle Grenzflächen (IFG)
Publikationstyp Zeitschriftenaufsatz
Jahr 2019
Sprache Englisch
Identifikator ISSN: 2520-1158
KITopen-ID: 1000091647
HGF-Programm 43.22.01 (POF III, LK 01)
Erschienen in Nature catalysis
Vorab online veröffentlicht am 18.02.2019
Schlagworte Characterization and analytical techniques; heterogeneous catalysis; nanoparticles
Nachgewiesen in Scopus
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