Identification of single-atom active sites in CO oxidation over oxide-supported Au catalysts

Schilling, Christian; Ziemba, Marc; Heß, Christian; Ganduglia‐Pirovano, M. V.

doi:10.1016/j.jcat.2020.01.022

Cited by 39 publications

(52 citation statements)

References 60 publications

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“…showed recently that isolated Au single sites, identified as O lattice ‐Au 1+ −CO species, are monitored during reaction and can be assumed as active Au species during CO oxidation. [71] Particle growth during reaction was also reported as a possible reason for the deactivation of Au/CeO 2 catalysts, [35] similarly to Au/TiO 2 . [72] …”

Section: Au Particle Size Distribution During Pre‐treatments and Reactionmentioning

confidence: 99%

Fundamental Aspects of Ceria Supported Au Catalysts Probed by In Situ/Operando Spectroscopy and TAP Reactor Studies

et al. 2021

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The discovery of the activity of dispersed gold nanoparticles three decades ago paved the way for a new era in catalysis. The unusual behavior of these catalysts sparked many questions about their working mechanism. In particular, Au/CeO2 proved to be an efficient catalyst in several reactions such as CO oxidation, water gas shift, and CO2 reduction. Here, by employing findings from operando X‐ray absorption spectroscopy at the near and extended Au and Ce LIII energy edges, we focus on the fundamental aspects of highly active Au/CeO2 catalysts, mainly in the CO oxidation for understanding their complex structure‐reactivity relationship. These results were combined with findings from in situ diffuse reflectance FTIR and Raman spectroscopy, highlighting the changes of adlayer and ceria defects. For a comprehensive understanding, the spectroscopic findings will be supplemented by results of the dynamics of O2 activation obtained from Temporal Analysis of Products (TAP). Merging these results illuminates the complex relationship among the oxidation state, size of the Au nanoparticles, the redox properties of CeO2 support, and the dynamics of O2 activation.

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Section: Au Particle Size Distribution During Pre‐treatments and Reactionmentioning

confidence: 99%

Fundamental Aspects of Ceria Supported Au Catalysts Probed by In Situ/Operando Spectroscopy and TAP Reactor Studies

et al. 2021

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“…The step‐site‐anchored Au + adsorbs CO strongly, and high CO oxidation activity (10 orders of magnitude higher than that of Au single atom on a CeO 2 terrace at 700 K) and thermal stability was reported on the Au 1 + (CO) structure (Figure 9b) [84] . The active structure of O lattice ‐Au + −CO on Au 1 /CeO 2 was further confirmed by a combined vibrational spectroscopic and theoretical study [86] . A combined scanning tunneling microscopy (STM) and X‐ray photoelectron spectroscopy (XPS) study on Au 1 /CuO further illustrated that CO oxidation reactivity can be determined by the charge transfer between Au and the support [87] .…”

Section: Sacs For Co Oxidationmentioning

confidence: 63%

“…[84] The active structure of O lattice -Au + À CO on Au 1 / CeO 2 was further confirmed by a combined vibrational spectroscopic and theoretical study. [86] A combined scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS) study on Au 1 /CuO further illustrated that CO oxidation reactivity can be determined by the charge transfer between Au and the support. [87] When a lattice O atom transfers a partial negative charge (δÀ ) to a Au single atom, the lattice O is activated and reacts with a CO (Figure 9c).…”

Section: Au Sacsmentioning

confidence: 99%

Single‐atom Automobile Exhaust Catalysts

Zhang

Fan

et al. 2020

ChemNanoMat

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Single-atom catalysts (SACs) with isolated metal centers are attracting great research interest because of their maximized metal utilization rates and unique structures. In the last decade, significant efforts have been made to design highly efficient and cost-effective SACs with applications in automobile exhaust aftertreatment. SACs have not only demonstrated their high potential for improving the catalytic performance of current automobile exhaust catalysts but also provided an ideal platform for understanding the origins of catalyst reactivity. In this review, we summarize the general strategies for promoting the reactivity of metal SACs while maintaining their thermal stability during exhaust-abatement-related reactions. Highlights are provided on wellperformed SACs for CO oxidation, unburnt hydrocarbon (HC) oxidation, and the selective catalytic reduction of NO x. The reaction mechanism and structure-performance relationship of SAC during these reactions are also discussed. Finally, perspectives are given on the trending research fields for designing more efficient single-atom automobile exhaust catalysts in the future.

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“…In our previous works, we observed, using (S)TEM technique, such Au clusters in Au/ CeO 2 (NC) annealed at 300 °C [32,33]. The second possible explanation is the presence of pseudo-single sites, i.e., gold ions slightly abstracted from a gold clusters, which exhibit lower activation energy in the rate-determining step of COoxidation [34]. However, these hypotheses require HR-(S) TEM + DRIFTS + DFT verification, which we are going to do in further study.…”

Section: Co-oxidationmentioning

confidence: 89%

The Sintering of Au Nanoparticles on Flat {100}, {111} and Zigzagged {111}-Nanofacetted Structures of Ceria and Its Influence on Catalytic Activity in CO Oxidation and CO PROX

et al. 2020

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The thermal stability of Au nanoparticles on ceria support of various morphology (nanocubes, nanooctahedra, and {111}-nanofacetted nanocubes) in oxidizing and reducing atmospheres was investigated by electron microscopy. A beneficial effect of the reconstruction of edges of ceria nanocubes into zigzagged {111}-nanofacetted structures on the inhibition of sintering of Au nanoparticles was shown. The influence of different morphology of Au particles on various ceria supports on the reducibility and catalytic activity in CO oxidation, and CO PROX of Au/ceria catalysts was also investigated and discussed. It was shown, that ceria nanocubes with flat {110} terminated edges are more suitable as a support for Au nanoparticles, used to catalyze CO oxidation, than zigzagged {111}- nanofacetted structures. Graphic Abstract

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Identification of single-atom active sites in CO oxidation over oxide-supported Au catalysts

Cited by 39 publications

References 60 publications

Fundamental Aspects of Ceria Supported Au Catalysts Probed by In Situ/Operando Spectroscopy and TAP Reactor Studies

Fundamental Aspects of Ceria Supported Au Catalysts Probed by In Situ/Operando Spectroscopy and TAP Reactor Studies

Single‐atom Automobile Exhaust Catalysts

The Sintering of Au Nanoparticles on Flat {100}, {111} and Zigzagged {111}-Nanofacetted Structures of Ceria and Its Influence on Catalytic Activity in CO Oxidation and CO PROX

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