Fabrication of 2-dimensional platinum nanocatalyst arrays by electron beam lithography: ethylene hydrogenation and CO-poisoning reaction studies

Contreras, A. M.; Grunes, Jeff; Yan, Xiaoming; Liddle, A.; Somorjai, Gábor A.

doi:10.1007/s11244-006-0047-0

Cited by 26 publications

(21 citation statements)

References 35 publications

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“…In this context, we have for several years been developing the synthesis of nanoparticles using an organometallic approach. [5] Pioneering 13 C MAS (magic angle spinning) NMR spectroscopy has shown the coordination of CO on ruthenium nanoparticles (Ru NPs) to occur in three different modes: terminal, bridging and multicarbonyl. It also allows the tuning of their surface chemistry through addition of ligands.…”

Section: Introductionmentioning

confidence: 99%

Surface Chemistry on Small Ruthenium Nanoparticles: Evidence for Site Selective Reactions and Influence of Ligands

Novio

Monahan

Coppel

et al. 2014

Chemistry A European J

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The reactivity of two classes of ruthenium nanoparticles (Ru NPs) of small size, either sterically stabilized by a polymer (polyvinylpyrrolidone, PVP) or electronically stabilized by a ligand (bisdiphenylphosphinobutane, dppb) was tested towards standard reactions, namely CO oxidation, CO2 reduction and styrene hydrogenation. The aim of the work was to identify the sites of reactivity on the nanoparticles and to study how the presence of ancillary ligands can influence the course of these catalytic reactions by using NMR and IR spectroscopies. It was found that CO oxidation proceeds at room temperature (RT) on Ru NPs but that the system deactivates rapidly in the absence of ligands because of the formation of RuO2. In the presence of ligands, the reaction involves exclusively the bridging CO groups and no bulk oxidation is observed at RT under catalytic conditions. The reverse reaction, CO2 reduction, is achieved at 120 °C in the presence of H2 and leads to CO, which coordinates exclusively in a bridging mode, hence evidencing the competition between hydrides and CO for coordination on Ru NPs. The effect of ligands localized on the surface is also evidenced in catalytic reactions. Thus, styrene is slowly hydrogenated at RT by the two systems Ru/PVP and Ru/dppb, first into ethylbenzene and then into ethylcyclohexane. Selectively poisoning the nanoparticles with bridging CO groups leads to catalysts that are only able to reduce the vinyl group of styrene whereas a full poisoning with both terminal and bridging CO groups leads to inactive catalysts. These results are interpreted in terms of location of the ligands on the particles surface, and evidence site selectivity for both CO oxidation and arene hydrogenation.

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Section: Introductionmentioning

confidence: 99%

Surface Chemistry on Small Ruthenium Nanoparticles: Evidence for Site Selective Reactions and Influence of Ligands

Novio

Monahan

Coppel

et al. 2014

Chemistry A European J

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“…Recent HP-XPS studies [16] utilizing such approaches have proven illuminating in investigating the effects of ambient reaction conditions on the surface composition and catalysis of alloy nanoparticles with carefully prepared core-shell structures. Additionally, investigators have employed lithography-based approaches [17][18][19][20][21] to generate surfaces containing arrays of well-defined nanoparticles, allowing a level of control over factors such as nanoparticle size and even interparticle distance. Investigations have demonstrated these surfaces can effectively simulate reaction kinetics observed on single crystal and supported catalyst surfaces [17,20,21] and have been employed to study catalysis in different types of reaction environments (e.g.…”

Section: Introductionmentioning

confidence: 99%

Simulating the Complexities of Heterogeneous Catalysis with Model Systems: Case studies of SiO2 Supported Pt-Group Metals

McClure

Goodman

2011

Top Catal

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Model catalyst surfaces, consisting of vapordeposited metal nanoparticles supported on a planar oxide support, can help to link reactivity studies on well-defined single crystal surfaces with those conducted on high-surface area supported catalysts. When coupled with near atmospheric pressure kinetic and spectroscopic techniques, these well-defined model catalyst surfaces represent a useful approach to combine the power of surface analytical techniques with reactivity studies under relevant reaction conditions. Here, we review recent results of our investigations characterizing the physical and catalytic properties of Pt/SiO 2 and Rh/SiO 2 model catalyst surfaces. As will be discussed, the model catalyst approach can help simulate the complexities of catalytic reactions on supported catalysts, helping to provide insights into the role of particle size, particle morphology, and surface adsorbates in dictating the observed structure-sensitivity (activity and selectivity) during reactions at near atmospheric pressures.

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“…Previous reports have demonstrated the fabrication of noble metal ͑Ag, Au, Pt͒ NPs and nanowires by EBL. 13,[15][16][17] The optical properties, especially LSPR, of EBL-derived Ag NPs have been widely characterized using optical microscopy and spectroscopy at micrometer and submicrometer resolution. Corrigan et al 13 studied the fluorescence enhancement on periodic Ag NP arrays and reported greater relative enhancement for triangular-shaped NPs compared to square-shaped ones.…”

Section: Introductionmentioning

confidence: 99%

Localized surface plasmon resonance of single silver nanoparticles studied by dark-field optical microscopy and spectroscopy

Cao

Huang

et al. 2011

Journal of Applied Physics

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Localized surface plasmon resonance (LSPR) of Ag nanoparticles (NPs) with different shapes and disk-shaped Ag NP pairs with varying interparticle distance is studied using dark-field optical microscopy and spectroscopy (DFOMS). Disk-, square-, and triangular-shaped Ag NPs were fabricated on indium tin oxide-coated glass substrates by electron beam lithography. The LSPR spectra collected from single Ag NPs within 5×5 arrays using DFOMS exhibited pronounced redshifts as the NP shape changed from disk to square and to triangular. The shape-dependent experimental LSPR spectra are in good agreement with simulations using the discrete dipole approximation model, although there are small deviations in the peak wavelengths for square- and triangular-shaped NPs. The LSPR spectra of disk-shaped Ag NP pairs with varying interparticle distances were acquired from five different locations across the pair axis. It was clearly observed that the LSPR wavelength redshifts as the interparticle distance decreases, indicating a strong interaction when two Ag NPs are close to each other.

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Fabrication of 2-dimensional platinum nanocatalyst arrays by electron beam lithography: ethylene hydrogenation and CO-poisoning reaction studies

Cited by 26 publications

References 35 publications

Surface Chemistry on Small Ruthenium Nanoparticles: Evidence for Site Selective Reactions and Influence of Ligands

Surface Chemistry on Small Ruthenium Nanoparticles: Evidence for Site Selective Reactions and Influence of Ligands

Simulating the Complexities of Heterogeneous Catalysis with Model Systems: Case studies of SiO2 Supported Pt-Group Metals

Localized surface plasmon resonance of single silver nanoparticles studied by dark-field optical microscopy and spectroscopy

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