scholarly journals Studies of the Acidity and Ionic Conductivity of Silica-Supported Heteropoly Compounds. II. Acidity and Catalytic Activity of Supported Heteropoly Compound Catalysts

1990 ◽  
Vol 63 (7) ◽  
pp. 2071-2075 ◽  
Author(s):  
Reiji Ohtsuka ◽  
Yoshio Morioka ◽  
Jun-ichi Kobayashi
Keyword(s):  
Catalytic Activity ◽  
Ionic Conductivity ◽  
Heteropoly Compound ◽  
Heteropoly Compounds

scholarly journals Efficiency of using heteropoly compounds of the type (NH4)2[Co(H2O)4]2[Mo8O27]∙6H2O as catalysts for the production of ethylene

2019 ◽  
Vol 60 (11) ◽  
pp. 85-92
Author(s):  
Nikita A. Panurin ◽  
◽  
Natalya Yu. Isaeva ◽  
Ekaterina B. Markova ◽  
Tatiana F. Sheshko ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Catalyst Deactivation ◽  
Coke Formation ◽  
Fluorescence Analysis ◽  
Heteropoly Compound ◽  
Cascade Reactions ◽  
Environmental Benefits ◽  
Heteropoly Compounds ◽  
X Ray ◽  
Cell Parameters

Carrying out heterogeneous acid catalysis with the use of heteropoly compounds has received considerable attention due to the great economic and environmental benefits. In spite of this, its industrial application is limited as there are difficulties in catalyst regeneration (settling) caused by its relatively low thermal stability. The aim of present work was to search and select catalysts related to the class of heteropoly compounds for propane cracking, to test the selectivity of the prosses as well as to discuss possible approaches for solving the problem of catalyst deactivation, that can contribute to achieve stable characteristics of solid heteropoly catalysts. Among these approaches are: the development of new catalysts with high thermal stability, the modification of catalysts to promote coke combustion, the inhibition of coke formation on heteropoly compound catalysts during the process, carrying out the reactions in supercritical media and also the cascade reactions using a multifunctional heteropoly catalyst. The obtained catalyst was also studied by physicochemical methods to get deep knowledge about which features of these compounds influence on the catalytic activity. A highly active and selective catalyst for ammonium octomolybdenocobaltate(II) ammonium (NH4)2[Co(H2O)4]2[Mo8O27]∙6H2O was synthesized for cracking associated petroleum gases. The qualitative, quantitative, and structural composition as well as the specific surface area of the obtained catalyst was established by the methods of X-ray diffraction, X-ray phase and fluorescence analysis. It was revealed that ammonium octomolybdenocobaltate(II) crystallizes in a triclinic syngony with cell parameters: а = 8.6292(9) Å b = 9.4795(10) Å c = 12.2071(13) Å α = 104.326(2)° β = 109.910(2)° γ = 100.820(2)°.

scholarly journals Oxidative Desulfurization of Dibenzothiophene Using Dawson Type Heteropoly Compounds/Tantalum as Catalyst

2018 ◽  
Vol 16 (1) ◽  
pp. 105 ◽  
Author(s):  
Risfidian Mohadi ◽  
Lusi Teresia ◽  
Najma Annuria Fithri ◽  
Aldes Lesbani ◽  
Nurlisa Hidayati
Keyword(s):  
Catalytic Activity ◽  
Vibration Spectrum ◽  
Oxidative Desulfurization ◽  
Heteropoly Compounds ◽  
Atmospheric Conditions ◽  
N2 Adsorption ◽  
Fresh Catalyst ◽  
Wet Impregnation ◽  
Percent Conversion ◽  
Adsorption Desorption

Catalyst (NH4)6[b-P2W18O62]/Ta has been synthesized by simple wet impregnation at 30-40 °C under atmospheric conditions using Dawson type polyoxometalate (NH4)6[b-P2W18O62] and tantalum. The catalyst was characterized by FTIR spectrophotometer, XRD, SEM, and N2 adsorption desorption methods. FTIR spectrum of (NH4)6[b-P2W18O62]/Ta showed that Dawson type polyoxometalate (NH4)6[b-P2W18O62] and Ta was successfully impregnated which was indicated by vibration spectrum at wavenumber of 900-1100 cm-1 for polyoxometalate and 550 cm-1 for Ta. The surface area of the (NH4)6[b-P2W18O62]/Ta after impregnation was higher than (NH4)6[b-P2W18O62]•nH2O and its morphology was found to be uniform. The catalytic activity of (NH4)6[b-P2W18O62]/Ta toward desulfurization of dibenzothiophene was three times higher than the original catalyst of (NH4)6[b-P2W18O62]•nH2O without impregnation. The catalytic regeneration test of catalyst (NH4)6[b-P2W18O62]/Ta showed that the catalytic activity for first regeneration of catalyst has similar catalytic activity with the fresh catalyst without loss of catalytic activity indicated by almost similar percent conversion.

Thermally reversible solidification of novel ionic liquid [im]HSO4 by self-nucleated rapid crystallization: investigations of ionic conductivity, thermal properties, and catalytic activity

RSC Advances ◽  
2016 ◽  
Vol 6 (110) ◽  
pp. 108896-108907 ◽  
Author(s):  
Michał Bielejewski ◽  
Mahdi Ghorbani ◽  
Mohammad Ali Zolfigol ◽  
Jadwiga Tritt-Goc ◽  
Soheila Noura ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Catalytic Activity ◽  
Thermal Properties ◽  
Solid State ◽  
Ionic Conductivity ◽  
Chemical Processes ◽  
Efficient Catalyst ◽  
Solid State Electrolyte ◽  
Rapid Crystallization ◽  
Acid Catalyzed

A new, multifunctional [im]HSO4 ionic liquid: a thermally reversible solid-state electrolyte and an efficient catalyst for acid-catalyzed chemical processes.

Remarkable ionic conductivity and catalytic activity in ceramic nanocomposite fuel cells

2018 ◽  
Vol 43 (28) ◽  
pp. 12892-12899 ◽  
Author(s):  
M.I. Asghar ◽  
S. Jouttijärvi ◽  
R. Jokiranta ◽  
P.D. Lund
Keyword(s):  
Catalytic Activity ◽  
Fuel Cells ◽  
Ionic Conductivity ◽  
Ceramic Nanocomposite

Transformations of Supported Heteropoly Compounds in Oxidative Conversion of Alkanes

2010 ◽  
Vol 1279 ◽  
Author(s):  
Svetlana A. Tungatarova
Keyword(s):  
Water Vapor ◽  
Heteropoly Compound ◽  
Heteropoly Compounds ◽  
Oxidation Reactions ◽  
Oxidative Conversion ◽  
Structural Conversion ◽  
New Findings ◽  
Actual Operation ◽  
Partial Oxidation Reactions ◽  
The Stability

AbstractDynamics of structural transformation of supported heteropoly compound was investigated by IR-spectroscopy, XRD, TPR, and TPO methods. The 15-30 wt.% H3PMo12O40 and H3PV2Mo10O40, supported on SiO2 catalysts were investigated in process under various conditions by interaction with O2 (air) in the presence of water vapor, H2, alkane in TPR regime, O2 in TPO regime (298-1273K) and H2O (298, 923K). The rank of reversible structural conversion of supported heteropoly compounds was established under influence of temperatureand medium. These new findings of reversible structural cycle explains the stability of the 12th series Mo heteropoly compounds supported on Si-containing carrier at high temperatures (873-1073K) which is close to the actual operation temperatures of the partial oxidation reactions and oxidative dehydrogenation of alkanes.

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