scholarly journals Formation and selected catalytic properties of ruthenium, rhodium, osmium and iridium nanoparticles

RSC Advances ◽  
2022 ◽  
Vol 12 (4) ◽  
pp. 2123-2144
Author(s):  
Jan Krajczewski ◽  
Robert Ambroziak ◽  
Andrzej Kudelski
Keyword(s):  
Catalytic Properties ◽  
Iridium Nanoparticles

The synthesis and applications in catalysis of nanoparticles formed from ruthenium, rhodium, osmium and iridium have been reviewed.

Nanostructures in ionic liquids: correlation of iridium nanoparticles’ size and shape with imidazolium salts’ structural organization and catalytic properties

2010 ◽  
Vol 12 (25) ◽  
pp. 6826 ◽  
Author(s):  
Pedro Migowski ◽  
Daniela Zanchet ◽  
Giovanna Machado ◽  
Marcos A. Gelesky ◽  
Sérgio R. Teixeira ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Structural Organization ◽  
Catalytic Properties ◽  
Imidazolium Salts ◽  
Size And Shape ◽  
Iridium Nanoparticles

ChemInform Abstract: Catalytic Properties of Soluble Iridium Nanoparticles

ChemInform ◽  
2010 ◽  
Vol 41 (2) ◽  
Author(s):  
Jackson D. Scholten ◽  
Jairton Dupont
Keyword(s):  
Catalytic Properties ◽  
Iridium Nanoparticles

Poly(Vinylpyrrolidone)-Anchored Iridium Nanoparticles Supported on Al2O3 as Ultra-Selective Catalyst for the Hydrogenation of p-Chloronitrobenzene

2013 ◽  
Vol 726-731 ◽  
pp. 683-686 ◽  
Author(s):  
Guang Yin Fan
Keyword(s):  
Great Improvement ◽  
Selective Hydrogenation ◽  
Catalytic Properties ◽  
Halogen Bond ◽  
Side Reaction ◽  
Colloidal Nanoparticles ◽  
Complete Conversion ◽  
Selective Catalyst ◽  
Iridium Nanoparticles ◽  
Lower Temperature

Poly (vinylpyrrolidone)-anchored iridium nanoparticles (PVP-Ir) were prepared via the reduction of H2IrCl6·nH2O in ethanol/water mixtures. The catalytic properties of the colloidal nanoparticles that dispersed on Al2O3(PVP-Ir/Al2O3) were investigated in the selective hydrogenation ofp-chloronitrobenzene (p-CNB) top-chloroaniline (p-CAN). The results indicated that the selectivity top-CAN remained on the level of 100 % at complete conversion ofp-CNB at lower temperature of 288 K. Moreover, the side reaction of hydrogenolysis of the carbon-halogen bond was completely inhibited in the absence of promoters and inhibitors. The great improvement on activity and selectivity of PVP-Ir/Al2O3was attributed to the highly and homogeneously dispersion of the iridium nanoparticles on the support Al2O3and the addition of appropriate amount of water in organic solvents

Microstructure and reactivity of small metal particles: The role of Ce additives

1992 ◽  
Vol 50 (1) ◽  
pp. 318-319
Author(s):  
L.D. Schmidt ◽  
K. R. Krause ◽  
J. M. Schwartz ◽  
X. Chu
Keyword(s):  
Atmospheric Pressure ◽  
Noble Metals ◽  
Mixed Oxides ◽  
Catalytic Properties ◽  
Chemical Shifts ◽  
Catalytic Converter ◽  
Structural Evolution ◽  
Single Particles ◽  
Small Metal Particles

The evolution of microstructures of 10- to 100-Å diameter particles of Rh and Pt on SiO2 and Al2O3 following treatment in reducing, oxidizing, and reacting conditions have been characterized by TEM. We are able to transfer particles repeatedly between microscope and a reactor furnace so that the structural evolution of single particles can be examined following treatments in gases at atmospheric pressure. We are especially interested in the role of Ce additives on noble metals such as Pt and Rh. These systems are crucial in the automotive catalytic converter, and rare earths can significantly modify catalytic properties in many reactions. In particular, we are concerned with the oxidation state of Ce and its role in formation of mixed oxides with metals or with the support. For this we employ EELS in TEM, a technique uniquely suited to detect chemical shifts with ∼30Å resolution.

Electron distribution change of small nickel particles encaged in X zeolite in presence of Ce3+ ions, related to their catalytic properties

1986 ◽  
Vol 83 ◽  
pp. 619-621 ◽  
Author(s):  
F. Vergand ◽  
B. Iraqi ◽  
C. Bonnelle ◽  
E. Ramaroson ◽  
M.F. Guilleux ◽  
...  
Keyword(s):  
Electron Distribution ◽  
Catalytic Properties ◽  
Distribution Change ◽  
Nickel Particles ◽  
X Zeolite

On the Preparation of Bovine α-Thrombin

1978 ◽  
Vol 39 (01) ◽  
pp. 193-200 ◽  
Author(s):  
Erwin F Workman ◽  
Roger L Lundblad
Keyword(s):  
Immobilized Enzyme ◽  
Catalytic Properties ◽  
Specific Activity ◽  
Guanidine Hydrochloride ◽  
Low Molecular Weight ◽  
Reversible Process ◽  
Gel Beads ◽  
Tissue Thromboplastin ◽  
C 50 ◽  
Hydrolysis Of

SummaryAn improved method for the preparation of bovine α-thrombin is described. The procedure involves the activation of partially purified prothrombin with tissue thromboplastin followed by chromatography on Sulfopropyl-Sephadex C-50. The purified enzyme is homogeneous on polyacrylamide discontinuous gel electrophoresis and has a specific activity toward fibrinogen of 2,200–2,700 N.I.H. U/mg. Its stability on storage in liquid media is dependent on both ionic strenght and temperature. Increasing ionic strength and decreasing temperature result in optimal stability. The denaturation of α-thrombin by guanidine hydrochloride was found to be a partially reversible process with the renatured species possessing properties similar to “aged” thrombin. In addition, the catalytic properties of a-thrombin covalently attached to agarose gel beads were also examined. The activity of the immobilized enzyme toward fibrinogen was affected to a much greater extent than was the hydrolysis of low molecular weight, synthetic substrates.

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