Generation of a supported iridium catalyst of extremely high dispersion

Anderson, John R.; Howe, Russell F.

doi:10.1038/268129a0

Cited by 33 publications

(8 citation statements)

References 4 publications

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“…This and the absence of any evidence for disintegration of the cluster suggest a reaction in which an oxygenated cluster reacts with CO as in Eqn (4). 6Rh(C0)2X+7CO + 3Hz0-Rh6(C0)16+3C02 + 6HX (3) This scheme still achieves the 1.3 ratio of COad, to COz produced even when starting from a fully oxygenated sample.…”

Section: Discussionmentioning

confidence: 89%

Studies of oxide supported metal clusters

Watters

1981

Surface & Interface Analysis

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The metal cluster carbonyl compounds, Rh,(CO),, and [Pt3(CO),];t-( n = 5 , 6 ) have been deposited from solution onto alumina and silica supports. Exposure to air results in decarbonylation of the surface supported compounds in each case. Gas adsorption and IR measurements for the alumina supported rhodium material indicate a unique and interesting chemistry in which CO and oxygen react with a surface species to form CO, and the surface rhodium material is reversibly converted from a fully carbonylated form [apparently Rh,(CO),,] to a fully oxygenated (decarbonylated) form which may retain the Rh6 cluster integrity.The supported platinum complexes displayed a more conventional chemistry. After deposition on alumina or silica they could be decarbonylated in air. Exposure to CO failed to regenerate the starting material, but behavior consistent with that reported for conventional reduced Pt on alumina or silica was observed.

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Section: Discussionmentioning

confidence: 89%

Studies of oxide supported metal clusters

Watters

1981

Surface & Interface Analysis

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“…Due to the diversity and the relatively easy removal of CO, metallic cluster carbonyl had become the preferred precursor. In the 1970s and 1980s, scientists used metal cluster carbonyls as the precursor to prepare surface-supported metal clusters by decarbonylation at elevated temperatures 26,[76][77][78][79][80][81][82] . Without atomic-resolution technologies, Infrared spectroscopy was a powerful characterization method to identify the structure of atomic clusters in these early studies.…”

Section: Vs Atomic Clusters Catalystsmentioning

confidence: 99%

“…Then, new strategies that can afford large-scale metal clusters were proposed. These synthetic methods include precursor-preselected strategy 18,26,27 , host-guest strategy 19,28,29 , wet chemical reduction 30,31 , dendrimerbased 32,33 , and atomic layer deposition method 34 . Considerable scientists have focused on the support effects and dynamic behavior of supported atomic clusters during heterogeneous catalytic processes via in situ techniques and theoretical calculations [35][36][37][38] .…”

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confidence: 99%

Synthetic strategies of supported atomic clusters for heterogeneous catalysis

et al. 2020

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Supported atomic clusters with uniform metal sites and definite low-nuclearity are intermediate states between single-atom catalysts (SACs) and nanoparticles in size. Benefiting from the presence of metal–metal bonds, supported atomic clusters can trigger synergistic effects among every metal atom, which contributes to achieving unique catalytic properties different from SACs and nanoparticles. However, the scalable and precise synthesis and atomic-level insights into the structure–properties relationship of supported atomic clusters is a great challenge. This perspective presents the latest progress of the synthesis of supported atomic clusters, highlights how the structure affects catalytic properties, and discusses the limitations as well as prospects.

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“…1982) remains of great interest in the field of homogeneous and heterogeneous catalysis. Among the various reasons for such an interest there are the 'cluster-surface analogy' Muetterties et al 1979;Johnson 1981;Ugo 1975;Muetterties 1975a, Basset & Ugo 1977Primet et al 1975), the availability of an increasing number of new clusters of increasing nuclearity (Lady et al 1975;Jackson et al 1980;Chini 1980), and the increasing number of molecular cluster carbonyls used as precursor (or effective) (Chini 1980;Pruett & Walker 1974;Robertson & Webb 1974;Anderson & Howe 1977) catalysts in 'CO catalysis' or related reactions. Consider also the great variety of catalytic reactions that can be carried out on metal surfaces and that are not yet known for mononuclear complexes.…”

Section: Introductionmentioning

confidence: 99%

“…Initially, the immobilisation of a cluster onto a support, followed by a thermal or photo chemical decarbonylation, appeared to be a way to transform a molecular cluster carbonyl ' poisoned ' by its carbonyl ligands into a very small particle of metal (Robertson & Webb 1974;Smith et al 1975Smith et al , 1978Ichikawa 1976;Anderson & Howe 1977;Kuznetzov et al 1980;Knozinger & Rumps 1978;Lieto & Gates 1980a, In fact such an approach proved to be much more complicated than expected (Smith et al 1979;Bilhou al. 1978;Besson al.…”

Section: Introductionmentioning

confidence: 99%

Catalysis by supported clusters: two examples of catalytic reactions that involve a molecular cluster frame

1982

Phil. Trans. R. Soc. Lond. A

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Two examples of catalysis by supported clusters are given that involve a molecular cluster frame during the catalytic cycle. (H)Os 3 (CO) 10 (OSi^) is able to hydrogenate ethylene between 343 and 373 K. The mechanism of this reaction, which involves the molecular cluster frame, requires the opening of the bridging three-electron oxygen ligand as the key step of the catalytic process. Rh 6 (CO) 16 adsorbed on alumina is a catalyst for the water-gas shift reaction carried out between 293 and 393 K. The mechanism of this reaction involves three steps: (i) electrophilic attack by surface protons on the metallic frame with formation of Rh I (CO) 2 and Rh III (H) (H) species; (ii) reductive elimination of H 2 favoured by CO coordination to the Rh III (H) (H) species; (iii) nucleophilic attack by molecular water on CO coordinated to Rh I with regeneration of the starting cluster, release of CO 2 and surface protons.

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Generation of a supported iridium catalyst of extremely high dispersion

Cited by 33 publications

References 4 publications

Studies of oxide supported metal clusters

Studies of oxide supported metal clusters

Synthetic strategies of supported atomic clusters for heterogeneous catalysis

Catalysis by supported clusters: two examples of catalytic reactions that involve a molecular cluster frame

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