The effect of single pd atoms on the energetics of recombinative O2 desorption from Au(111)

Lucci, Felicia R.; Zhang, Liang; Thuening, Theodore; Uhlman, Matthew B.; Schilling, Alex C.; Henkelman, Graeme; Sykes, E. Charles H.

doi:10.1016/j.susc.2018.08.001

Cited by 20 publications

(19 citation statements)

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“…For some other reactions, clusters of the catalytically active metal atom are needed to activate chemical bonds and obtain the desired products. For example, contiguous Pd sites are necessary for O 2 activation in the CO oxidation reaction, whereas single Pd atoms in Au are inactive for this reaction 16 , 17 . Also, Pd nanoparticles (NPs) are needed for the methane oxidation reaction, and the decomposition of the NPs into single Pd atoms at high temperatures leads to a drop in reactivity 18 .…”

Section: Introductionmentioning

confidence: 99%

Directing reaction pathways via in situ control of active site geometries in PdAu single-atom alloy catalysts

et al. 2021

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The atomic scale structure of the active sites in heterogeneous catalysts is central to their reactivity and selectivity. Therefore, understanding active site stability and evolution under different reaction conditions is key to the design of efficient and robust catalysts. Herein we describe theoretical calculations which predict that carbon monoxide can be used to stabilize different active site geometries in bimetallic alloys and then demonstrate experimentally that the same PdAu bimetallic catalyst can be transitioned between a single-atom alloy and a Pd cluster phase. Each state of the catalyst exhibits distinct selectivity for the dehydrogenation of ethanol reaction with the single-atom alloy phase exhibiting high selectivity to acetaldehyde and hydrogen versus a range of products from Pd clusters. First-principles based Monte Carlo calculations explain the origin of this active site ensemble size tuning effect, and this work serves as a demonstration of what should be a general phenomenon that enables in situ control over catalyst selectivity.

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Section: Introductionmentioning

confidence: 99%

Directing reaction pathways via in situ control of active site geometries in PdAu single-atom alloy catalysts

et al. 2021

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“…Many recent studies of SAAs have reported adsorption energies and reactivity at the active dopant site (see, e.g., refs − ), with most studies on SAAs reporting adsorption energies on the most stable site, which is usually the dopant site. ,, Different sites, in the vicinity of the dopant on the host surface of the SAA, are rarely considered and compared. Exceptions are works by Hu and co-workers, who studied the adsorption of oxygen on different sites of dilute Pt-based alloys, from which formulas for predicting adsorption energies at different sites were developed. , Recent machine learning approaches by Reuter and co-workers can also predict adsorption energies on various sites on a wide range of alloys, including SAAs.…”

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confidence: 99%

Periodic Trends in Adsorption Energies around Single-Atom Alloy Active Sites

Schumann

Bao

Hannagan

et al. 2021

J. Phys. Chem. Lett.

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Single-atom alloys (SAAs) make up a special class of alloy surface catalysts that offer well-defined, isolated active sites in a more inert metal host. The dopant sites are generally assumed to have little or no influence on the properties of the host metal, and transport of chemical reactants and products to and from the dopant sites is generally assumed to be facile. Here, by performing density functional theory calculations and surface science experiments, we identify a new physical effect on SAA surfaces, whereby adsorption is destabilized by ≤300 meV on host sites within the perimeter of the reactive dopant site. We identify periodic trends for this behavior and demonstrate a zone of exclusion around the reactive sites for a range of adsorbates and combinations of host and dopant metals. Experiments confirm an increased barrier for diffusion of CO toward the dopant on a RhCu SAA. This effect offers new possibilities for understanding and designing active sites with tunable energetic landscapes surrounding them.

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“…In addition, the herringbone profile changes as the bright clusters appear and island shape changes, which is highlighted by pink dashed lines in Figure c,d. After the oxidation, regions with darker apparent height are formed at the edge of the island (Figure f,g), which can be ascribed to attached manganese oxide domains . The oxidation process completes when O 2 pressure increases to ∼10 –6 mbar (Figure e).…”

Section: Resultsmentioning

confidence: 96%

“…After the oxidation, regions with darker apparent height are formed at the edge of the island (Figure 2f,g), which can be ascribed to attached manganese oxide domains. 51 The oxidation process completes when O 2 pressure increases to ∼10 −6 mbar (Figure 2e). However, there is a possibility that such oxidation can be achieved at 10 −7 mbar of O 2 with a longer time, since the Mn/Au(111) surface can be further oxidized when exposed to (2−3.5) × 10 −7 mbar of O 2 for 21 min (Figure S4).…”

Section: Resultsmentioning

confidence: 99%

Dynamic Structural Evolution of Mn–Au Alloy and MnO_x Nanostructures on Au(111) under Different Atmospheres

et al. 2021

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Construction of inverse oxide/metal model catalyst with specific chemical composition and interfacial structure is essential for clarifying their structure−performance relationship. This work describes the structural evolution of Mn−Au surface alloy and two-dimensional manganese oxide (MnO x ) islands on Au(111) surface under different treatment conditions. By employing near-ambient pressure scanning tunneling microscopy and Xray photoelectron spectroscopy, we can obtain four different MnO x structures. Among them, double-layer square lattice Mn 3 O 4 (001) and monolayer parallelogram-shaped Mn 3 O 4 are prepared by postannealing Mn−Au surface alloy in "oxygen-poor" and "oxygenrich" regimes, respectively. Annealing the monolayer parallelogram-shaped Mn 3 O 4 in vacuum to 700 K produces a double-layer structure consisting of Mn 3 O 4 top layer and MnO(111) bottom layer, while double-layer MnO(111) is formed after annealing in vacuum to 800 K. Our study lays the foundation for exploring the catalytic properties of inverse manganese oxide/metal model catalysts.

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The effect of single pd atoms on the energetics of recombinative O2 desorption from Au(111)

Cited by 20 publications

References 62 publications

Directing reaction pathways via in situ control of active site geometries in PdAu single-atom alloy catalysts

Directing reaction pathways via in situ control of active site geometries in PdAu single-atom alloy catalysts

Periodic Trends in Adsorption Energies around Single-Atom Alloy Active Sites

Dynamic Structural Evolution of Mn–Au Alloy and MnO_x Nanostructures on Au(111) under Different Atmospheres

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The effect of single pd atoms on the energetics of recombinative O2 desorption from Au(111)

Cited by 20 publications

References 62 publications

Directing reaction pathways via in situ control of active site geometries in PdAu single-atom alloy catalysts

Directing reaction pathways via in situ control of active site geometries in PdAu single-atom alloy catalysts

Periodic Trends in Adsorption Energies around Single-Atom Alloy Active Sites

Dynamic Structural Evolution of Mn–Au Alloy and MnOx Nanostructures on Au(111) under Different Atmospheres

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Dynamic Structural Evolution of Mn–Au Alloy and MnO_x Nanostructures on Au(111) under Different Atmospheres