scholarly journals Preparation of Alumina Pillared Montmorillonite Clays Employing Ultrasonics and Their Catalytic Properties

2016 ◽  
Vol 2 (1) ◽  
pp. 53 ◽  
Author(s):  
Suhas P. Katdare ◽  
Veda Ramaswamy ◽  
A.V. Ramaswamy
Keyword(s):  
Catalytic Properties ◽  
Pillared Clay ◽  
Ultrasonic Technique ◽  
Cumene Cracking ◽  
Montmorillonite Clays ◽  
Alkylation Of Benzene ◽  
Acid Centers ◽  
Catalytic Applications ◽  
Clay Catalysts

<p>An accelerated diffusion of alumina precursor species in-between the gallery region of montmorillonite clays by the use of ultrasonic technique is described. This method offers a faster, efficient and attractive route for the synthesis of alumina-pillared clay catalysts. Out of the several preparative parameters studied, the role of pre-exchanged cations influenced the optimum duration of ultrasonic agitation and treatment for the pillaring process. By comparing ultrasonic route and conventional preparation procedure, it is revealed that uniform spacing of alumina pillars in the clay means homogeneously distributed acid centers. The influence of calcination temperature on the acidity and hence the catalytic activity is described. The choice of three different montmorillonite clays with different cation exchange capacities enables one to tune the pore dimensions of the pillared clays. The catalytic applications include studies on cumene cracking, dehydration of propan-2-ol and alkylation of benzene with linear olefins. </p>

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.

scholarly journals Phosphofructokinase from bumblebee flight muscle. Molecular and catalytic properties and role of the enzyme in regulation of the fructose 6-phosphate/fructose 1,6-bisphosphate cycle.

1988 ◽  
Vol 263 (33) ◽  
pp. 17527-17533
Author(s):  
A Leite ◽  
J A Neto ◽  
J F Leyton ◽  
O Crivellaro ◽  
H A el-Dorry
Keyword(s):  
Flight Muscle ◽  
Catalytic Properties ◽  
Fructose 1,6 Bisphosphate

Pt-porous ZnO nanoribbon hybrid materials with enhanced catalytic performances

CrystEngComm ◽  
2015 ◽  
Vol 17 (8) ◽  
pp. 1765-1768 ◽  
Author(s):  
Zhiqiang Cheng ◽  
Mingyue Yu ◽  
Guixia Yang ◽  
Lijuan Kang
Keyword(s):  
Photocatalytic Degradation ◽  
Co Oxidation ◽  
Hybrid Materials ◽  
Catalytic Properties ◽  
Seeded Growth ◽  
Hybrid Nanomaterial ◽  
Growth Method ◽  
Catalytic Applications ◽  
Catalytic Performances

With the help of bio-molecule l-lysine, a seeded growth method has been developed and Pt–ZnO porous nanoribbons have been successfully obtained. For the catalytic applications of CO oxidation and the photocatalytic degradation of MO, the hybrid nanomaterial exhibits remarkably enhanced catalytic properties.

Catalytic Properties of a MnIII-Salen Complex Immobilised in a Pillared Clay by Simultaneous Pillaring/Encapsulation Procedures

2005 ◽  
Vol 2005 (5) ◽  
pp. 837-844 ◽  
Author(s):  
Beatriz Cardoso ◽  
Jo�o Pires ◽  
Ana P. Carvalho ◽  
Manuela B. Carvalho ◽  
Iwona Ku?niarska-Biernacka ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Pillared Clay ◽  
Salen Complex

scholarly journals Enhancement of aromatase activity by D-aspartic acid in the ovary of the lizard Podarcis s. sicula

Reproduction ◽  
2001 ◽  
pp. 803-808 ◽  
Author(s):  
L Assisi ◽  
V Botte ◽  
A D'Aniello ◽  
MM Di Fiore
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Reproductive Cycle ◽  
Catalytic Properties ◽  
Ovarian Tissue ◽  
Experimental Treatment ◽  
Tissue Homogenate ◽  
Aromatase Activity

The present study investigated the role of D-aspartic acid (D-Asp) in ovarian steroidogenesis and its effect on aromatase activity in the lizard, Podarcis s. sicula. It was determined that D-Asp concentrations vary significantly during phases of the reproductive cycle: they vary inversely with testosterone concentrations and directly with oestradiol concentrations in the ovary and plasma. Experimental treatment showed that administration of D-Asp induces a decrease in testosterone and an increase in oestradiol, and that treatment with other amino acids (L-Asp, D-Glu and D-Ala) instead of D-Asp has no effects. Experiments in vitro confirmed these results. Furthermore, these experiments showed an increase in aromatase activity, as the addition of D-Asp either to fresh ovarian tissue homogenate or to acetonic powder of ovarian follicles induced a significant increase in the conversion of testosterone to oestradiol. Aromatase activity is four times greater in the presence of D-Asp than in its absence. However, almost equivalent values of the two K(m) values (both approximately 25 nmol l(-1)) indicate that aromatase has the same catalytic properties in both cases.

ChemInform Abstract: Propene Alkylation of Liquid Phase Biphenyl Catalyzed by Alumina Pillared Clay Catalysts

ChemInform ◽  
2010 ◽  
Vol 23 (36) ◽  
pp. no-no
Author(s):  
J.-R. BUTRUILLE ◽  
T. J. PINNAVAIA
Keyword(s):  
Liquid Phase ◽  
Pillared Clay ◽  
Clay Catalysts

Role of Citric Acid/Glycine-Reinforced Nanometal Oxide for the Enhancement of Physio-chemical Specifications in Catalytic Properties

2020 ◽  
Vol 33 (12) ◽  
pp. 3893-3901
Author(s):  
S. Mangala Devi ◽  
A. Nivetha ◽  
I. Prabha
Keyword(s):  
Citric Acid ◽  
Catalytic Properties
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