High stability of thiol-protected colloidal platinum nanoparticles with reduced ligand coverages in the hydrogenation of 3-hexyne

Wand, Patricia; Kratzer, Eva; Cokoja, Mirza; Tschurl, Martin

doi:10.1016/j.catcom.2017.06.040

Cited by 10 publications

(2 citation statements)

References 28 publications

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“…In recent years, the unprotected platinum group metal and their alloy nanoclusters prepared by using the alkaline EG method have been widely used as building blocks for fabricating excellent organic ligands-modified metal or alloy nanocluster catalysts for the hydrogenation of aromatic chloronitro compounds, asymmetric hydrogenation of keto esters or hydrogenation of 3-hexyne, etc. [ 119 , 120 , 121 , 122 , 123 ], and the effect of the ligands on the catalytic properties of metal or alloy nanocluster catalysts were studied [ 35 , 38 , 95 , 124 , 125 , 126 , 127 , 128 , 129 , 130 ].…”

Section: Applications Of “Unprotected” Metal Nanoclustersmentioning

confidence: 99%

Metal Nanoclusters Synthesized in Alkaline Ethylene Glycol: Mechanism and Application

Wang

Hao

2023

Nanomaterials

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The “unprotected” metal and alloy nanoclusters (UMCs) prepared by the alkaline ethylene glycol method, which are stabilized with simple ions and solvent molecules, have the advantages of a small particle size, a narrow size distribution, good stability, highly efficient preparation, easy separation, surface modification and transfer between different phases. They can be composited with diverse materials to prepare catalytic systems with controllable structures, providing an effective means of studying the different factors’ effects on the catalytic properties separately. UMCs have been widely used in the development of high-performance catalysts for a variety of functional systems. This paper will review the research progress on the formation mechanism of the unprotected metal nanoclusters, exploring the structure–function relationship of metal nanocluster catalysts and the preparation of excellent metal catalysts using the unprotected metal nanoclusters as building blocks or starting materials. A principle of the influence of carriers, ligands and modifiers in metal nanocluster catalysts on the catalytic properties is proposed.

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Section: Applications Of “Unprotected” Metal Nanoclustersmentioning

confidence: 99%

Metal Nanoclusters Synthesized in Alkaline Ethylene Glycol: Mechanism and Application

Wang

Hao

2023

Nanomaterials

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“…However, a common disadvantage of these chemical methods is the presence of residual impurities, coming from the anion group of the metal salts not fully burned off in the calcination process or from capping ligands, as used purposely to reduce cluster aggregation. Some researchers report that capping ligands can either decrease the cluster activity by hindering reagent access to the catalyst or can increase the activity via electron donation . The existence of these impurities complicates the explanation of the original catalytic activity of the cluster, and can sometimes lead to misinterpretations.…”

Section: Introductionmentioning

confidence: 99%

Performance of Preformed Au/Cu Nanoclusters Deposited on MgO Powders in the Catalytic Reduction of 4‐Nitrophenol in Solution

Cai

Ellis

Yin

et al. 2018

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clusters (nanoparticles) of tunable size typically below 10 nm are pre-assembled into a beam and then deposited in a vacuum chamber onto the catalyst support. [1][2][3][4] Potential advantages of the approach include the absence of solvent and effluent in the catalyst synthesis; control of cluster size, composition, and morphology; and the absence of ligands compared with colloidal routes. [5][6][7][8] However, the technique is at an early stage, [9] most especially where catalytic behavior under realistic reaction conditions is concerned. Thus, there is an urgent need to validate the performance of this new class of nanomaterials in a series of model chemical transformations, and compare their behavior with catalysts prepared by more traditional and well-established routes. In this work, we report a first investigation of a solution phase transformation performed by nanoalloy catalysts prepared by cluster beam deposition.The discovery of the catalytic activity of gold (Au) nanoparticles for low-temperature oxidation of carbon monooxide (CO) provoked an explosion of interest in gold catalysis. [10,11] Au clusters can catalyze a range of reactions, for example, the water-gas shift reaction [12][13][14] and selective oxidation of carbon-carbon double bonds [15,16] and carbon-oxygen bonds. [17,18] The 4-nitrophenol The deposition of preformed nanocluster beams onto suitable supports represents a new paradigm for the precise preparation of heterogeneous catalysts. The performance of the new materials must be validated in model catalytic reactions. It is shown that gold/copper (Au/Cu) nanoalloy clusters (nanoparticles) of variable composition, created by sputtering and gas phase condensation before deposition onto magnesium oxide powders, are highly active for the catalytic reduction of 4-nitrophenol in solution at room temperature. Au/Cu bimetallic clusters offer decreased catalyst cost compared with pure Au and the prospect of beneficial synergistic effects. Energy-dispersive X-ray spectroscopy coupled with aberration-corrected scanning transmission electron microscopy imaging confirms that the Au/Cu bimetallic clusters have an alloy structure with Au and Cu atoms randomly located. Reaction rate analysis shows that catalysts with approximately equal amounts of Au and Cu are much more active than Au-rich or Cu-rich clusters. Thus, the interplay between the Au and Cu atoms at the cluster surface appears to enhance the catalytic activity substantially, consistent with model density functional theory calculations of molecular binding energies. Moreover, the physically deposited clusters with Au/Cu ratio close to 1 show a 25-fold higher activity than an Au/Cu reference sample made by chemical impregnation.Heterogeneous Catalysts

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Steric and Electronic Effects of Phosphane Additives on the Catalytic Performance of Colloidal Palladium Nanoparticles in the Semi‐Hydrogenation of Alkynes

et al. 2020

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We report on the influence of phosphanes on the catalytic activity and selectivity of colloidal, tetraoctylammonium bromide (TOAB) stabilised palladium nanoparticles (NPs) in the semi‐hydrogenation of alkynes to olefins. Full characterisation of the catalytic system (HRTEM, EDX, XPS, IR, NMR) confirmed the formation of spherical particles with a narrow size distribution (1.9±0.5 nm). The catalytic performance of the Pd NPs in the semi‐hydrogenation of 1‐octyne, 2‐octyne and phenylacetylene to the respective olefins and the influences on the selectivity was investigated. The system shows high activities and selectivities at mild conditions (0 °C and 1.0 bar H2 pressure). It was shown that generally, phosphanes lead to an increase of both the reaction rate and selectivity towards the olefin where both steric and electronic effects of the ligand play a crucial role for the catalyst performance. A moderate steric demand of the ligand with a rather weak σ‐donating ability turned out to give the highest catalytic performance.

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High stability of thiol-protected colloidal platinum nanoparticles with reduced ligand coverages in the hydrogenation of 3-hexyne

Cited by 10 publications

References 28 publications

Metal Nanoclusters Synthesized in Alkaline Ethylene Glycol: Mechanism and Application

Metal Nanoclusters Synthesized in Alkaline Ethylene Glycol: Mechanism and Application

Performance of Preformed Au/Cu Nanoclusters Deposited on MgO Powders in the Catalytic Reduction of 4‐Nitrophenol in Solution

Steric and Electronic Effects of Phosphane Additives on the Catalytic Performance of Colloidal Palladium Nanoparticles in the Semi‐Hydrogenation of Alkynes

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