Synthesis and decarbonylation of platinum carbonyl cluster anions in zeolite NaY made basic by treatment with CsOH

Chang, J.-R.; Xu, Zhongxing; Purnell, S. K.; Gates, B. C.

doi:10.1016/0304-5102(93)87109-l

Cited by 18 publications

(5 citation statements)

References 22 publications

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“…1) react with metal oxide surfaces, including, for example Ru 3 (CO) 12 , [8][9][10][11][12] Rh 6 (CO) 16 , [13][14][15][16][17][18] Ir 4 (CO) 12 , 13,[19][20][21] Os 3 (CO) 12 , [22][23][24] and the Chini clusters [Pt 3 (CO) 6 ] n 2À , n = 2-10. 25,26 In many cases, metal carbonyl clusters adsorb intact without removal of ligands. The metal frames in these precursors are typically quite stable.…”

Section: Iia1 Synthesis From Metal Carbonyl Cluster Precursorsmentioning

confidence: 99%

Metal clusters on supports: synthesis, structure, reactivity, and catalytic properties

2010

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This review of structurally simple and essentially molecular metal clusters on solid supports addresses synthesis, characterization, reactivity, and catalysis. Examples of supported clusters made in high yields are Os(3), Ir(4), Ir(6), and Rh(6), and typical supports are MgO, gamma-Al(2)O(3), and zeolites. Supported clusters are synthesized by adsorption of ligated molecular metal clusters, deposition of bare size-selected metal clusters from the gas phase, and adsorption of metal complexes followed by treatment to form clusters. Some metal clusters on supports have been imaged with atomic resolution. Reactions of supported metal clusters include ligand modifications, oxidative fragmentation, and migration leading to aggregation. Reactivities and catalytic properties of the clusters (e.g., for alkene hydrogenation and epoxidation) depend on the cluster size and the support (which acts as a ligand) and are distinct from those of supported particles that resemble bulk metals. Opportunities for deeper understanding of the chemistry of supported metal clusters hinge on improvements in characterization techniques such as X-ray absorption spectroscopy and high-resolution transmission electron microscopy.

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Section: Iia1 Synthesis From Metal Carbonyl Cluster Precursorsmentioning

confidence: 99%

Metal clusters on supports: synthesis, structure, reactivity, and catalytic properties

2010

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“…In that study, they suggested that CO induces the formation of new, neutral platinum−carbonyl clusters inside the zeolite. While anionic platinum clusters can be synthesized from precursor complexes as [Pt(NH 3 ) 4 ] 2+ and CO, − these complexes have not been prepared from reduced platinum metal particles. EXAFS and FTIR studies have shown the reconstruction of reduced rhodium particles supported on Al 2 O 3 or TiO 2 after admission of CO, , resulting in monorhodium−carbonyl clusters.…”

Section: Introductionmentioning

confidence: 99%

The Effect of CO Adsorption at Room Temperature on the Structure of Supported Pt Particles

1999

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To improve the understanding of the applicability of CO-FTIR spectroscopy for probing the electronic properties of catalysts, the effect of CO adsorption on the geometry of small metal particles in Pt/LTL and Pt/SiO 2 catalysts with varying support acidities was determined by comparison of X-ray absorption spectra before and after CO adsorption. At room temperature, the platinum particles (first shell coordination number N > 5) supported on SiO 2 were stable under CO atmosphere. By contrast, the smaller platinum particles (N < 5) in zeolite LTL reconstructed with the formation of very small platinum-CO aggregates upon admission of CO at room temperature. For both Pt/SiO 2 and Pt/LTL the linear-to-bridge ratio (L/B) of the CO infrared bands is a function of the support acidity/alkalinity. In the case of Pt/SiO 2 , the L/B ratio directly reflects the electronic properties of the catalytically active metal, since the metal particles do not reconstruct. The results show that the structure of the platinum particles in LTL zeolite, which participate in catalytic reactions is not the same as the Pt-CO aggregate analyzed by FTIR. Nevertheless, both the catalytic activity and L/B ratio are a function of support acidity.

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“…Also this type of cluster is formed by reduction of Pt-salts (e.g. Pt(NH 3 ) 4 ] 2+ ) with CO in zeolites of mainly basic properties. − Catalytic activity was reported for clusters with n = 3, 4 entrapped in zeolites in the reduction of NO by CO as well as for the water gas shift reaction …”

Section: Introductionmentioning

confidence: 99%

“…Pt(NH 3 ) 4 ] 2+ ) with CO in zeolites of mainly basic properties. [12][13][14] was reported for clusters with n ) 3, 4 entrapped in zeolites in the reduction of NO by CO 15 as well as for the water gas shift reaction. 16 Bradley et al reported on the formation of Chini clusters when CO was added to a Pt-colloid consisting of very small particles (<0.8 nm) in wet methylcyclohexane.…”

Section: Introductionmentioning

confidence: 99%

Formation of a Pt-Carbonyl Colloid by Reaction of Colloidal Pt with CO

Henglein

1997

J. Phys. Chem. B

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The formation of Pt-carbonyls upon the action of carbon monoxide on colloidal Pt in aqueous media made by the citrate method is investigated. The formation of carbonyls as well as their subsequent reactions are monitored with UV/vis absorption spectroscopy. The Pt-carbonyls formed are aggregates of the well-known Pt-carbonyl family [Pt3(CO)6] n 2- with n = 1 to ∼10. The aggregation occurs either with the carbonyl molecules or with small clusters of Pt. A very similar product is formed if H2PtCl6 is treated with CO in aqueous media. The formation of carbonyls from the Pt-colloid does not proceed if the colloid was treated with hydrogen before the action of carbon monoxide. It seems that a prerequisite for the formation of carbonyls is the presence of unreduced Pt-ions adsorbed on the particle surface. The conversion of Pt-colloid into carbonyls proceeds with about 80−90% yield. If the Pt-carbonyl colloid is treated with KOH, formation of isolated [Pt9(CO)18]2- clusters is observed. The kinetics of this reaction is strongly dependent on the amount of added KOH.

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Synthesis and decarbonylation of platinum carbonyl cluster anions in zeolite NaY made basic by treatment with CsOH

Cited by 18 publications

References 22 publications

Metal clusters on supports: synthesis, structure, reactivity, and catalytic properties

Metal clusters on supports: synthesis, structure, reactivity, and catalytic properties

The Effect of CO Adsorption at Room Temperature on the Structure of Supported Pt Particles

Formation of a Pt-Carbonyl Colloid by Reaction of Colloidal Pt with CO

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