Catalytic properties of catechol 1,2-dioxygenase from Acinetobacter radioresistens S13 immobilized on nanosponges

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.

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Influence of the reaction time on the physical–chemical and catalytic properties of vanadium phosphate catalysts prepared by a eutectic mixture

Micro & Nano Letters ◽

10.1049/mnl.2019.0048 ◽

2019 ◽

Vol 14 (11) ◽

pp. 1126-1130

Author(s):

Qi Zhang ◽

Weiguo Fang ◽

Qian Li

Keyword(s):

Reaction Time ◽

Catalytic Properties ◽

Eutectic Mixture ◽

Vanadium Phosphate ◽

Physical Chemical

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

Journal de Chimie Physique ◽

10.1051/jcp/1986830619 ◽

1986 ◽

Vol 83 ◽

pp. 619-621 ◽

Cited By ~ 6

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

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Countercation effects on surface and catalytic properties of 12-tungstophosphates

Journal de Chimie Physique ◽

10.1051/jcp/1992890681 ◽

1992 ◽

Vol 89 ◽

pp. 681-693

Author(s):

A Anwar ◽

AA Abdel-Ghaffar

Keyword(s):

Catalytic Properties

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On the Preparation of Bovine α-Thrombin

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646669 ◽

1978 ◽

Vol 39 (01) ◽

pp. 193-200 ◽

Cited By ~ 7

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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