scholarly journals Catalytic Properties of BF3-treated Aluminas. IV. The Effect of BF3Adsorption on the Acidic Properties of Aluminum Oxides

1972 ◽  
Vol 45 (7) ◽  
pp. 2079-2083 ◽  
Author(s):  
Kanjiro Matsuura ◽  
Akira Suzuki ◽  
Mitsuomi Itoh
Keyword(s):  
Catalytic Properties ◽  
Acidic Properties ◽  
Aluminum Oxides

A study of the catalytic properties of the nitrile hydratase immobilized on aluminum oxides and carbon-containing adsorbents

2010 ◽  
Vol 46 (4) ◽  
pp. 379-384 ◽  
Author(s):  
Yu. G. Maksimova ◽  
V. A. Demakov ◽  
A. Yu. Maksimov ◽  
G. V. Ovechkina ◽  
G. A. Kovalenko
Keyword(s):  
Nitrile Hydratase ◽  
Catalytic Properties ◽  
Aluminum Oxides

scholarly journals Effect of Acid Treatment on the Properties of Zeolite Catalyst for Straight-Run Gasoline Upgrading

2021 ◽  
Vol 1 (4) ◽  
pp. 1-1
Author(s):  
Ludmila Velichkina ◽  
◽  
Yakov Barbashin ◽  
Alexander Vosmerikov ◽  
◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Acid Treatment ◽  
Catalytic Properties ◽  
Fixed Bed ◽  
Acid Sites ◽  
Gasoline Fraction ◽  
Zeolite Catalysts ◽  
Acidic Properties

The objective of this research was to analyze the effect of different concentrations of nitric and hydrochloric acids on the structural, acidic, and catalytic properties of a post-synthetic treated ZSM-5 type zeolite at various temperatures. The properties of zeolite catalysts were determined using different methods, such as the Brunauer-Emmett-Teller (BET) method for specific surface area, temperature-programmed desorption (TPD) of ammonia method for acidic properties, and a flow-through unit with fixed bed catalyst (with upgrading straight-run gasoline fraction of oil) for catalytic activities of initial zeolite and acid-treated samples. The structural and acidic properties of both untreated and treated zeolites were investigated, and the effect of acid treatment on the catalytic properties of the samples in the course of upgrading the straight-run gasoline fraction of oil was determined. The post-synthetic treatment with aqueous nitric acid increased the specific surface area and volume of micropores of ZSM-5 zeolite, while the treatment with aqueous hydrochloric acid led to the formation of mesopores. Acid treatments of zeolite decreased the number of acid sites, mainly due to diminished concentration of low-temperature sites. The yield of liquid products in the conversion of straight-run gasoline fraction of oil, i.e., generation of high-octane gasolines with improved environmental features, was increased using acid-treated zeolites, which was due to the decrease in arene content.

Facet-dependent acidic and catalytic properties of sulfated titania solid superacids

2015 ◽  
Vol 51 (75) ◽  
pp. 14219-14222 ◽  
Author(s):  
Yichen Hu ◽  
Bin Guo ◽  
Yingyi Fu ◽  
Yuanhang Ren ◽  
Gangfeng Tang ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Acidic Properties ◽  
Sulfated Titania ◽  
Solid Superacids

Sulfated titania solid superacids with different dominant facets were prepared and dominant {001} facets facilitated the enhancement of acidic properties.

scholarly journals Physicochemical and Catalytic Properties of Vanadia/Titania Catalysts. III. Acidic Properties

2001 ◽  
Vol 19 (9) ◽  
pp. 691-700 ◽  
Author(s):  
Th. El-Nabarawy ◽  
M.N. Alaya ◽  
S.A. Sayed Ahmed ◽  
A.M. Youssef
Keyword(s):  
Catalytic Properties ◽  
Acidic Properties

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.

Sign in / Sign up

Export Citation Format

Share Document