Hydroisomerization of long-chain n-alkanes on bifunctional Pt/zeolite catalysts: Effect of the zeolite structure on the product selectivity and on the reaction mechanism

2008 ◽  
Vol 336 (1-2) ◽  
pp. 23-28 ◽  
Author(s):  
A. Soualah ◽  
J.L. Lemberton ◽  
L. Pinard ◽  
M. Chater ◽  
P. Magnoux ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Zeolite Catalysts ◽  
Product Selectivity ◽  
Zeolite Structure ◽  
Long Chain

scholarly journals CuZnZr-Zeolite Hybrid Grains for DME Synthesis: New Evidence on the Role of Metal-Acidic Features on the Methanol Conversion Step

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 671
Author(s):  
Massimo Migliori ◽  
Antonio Condello ◽  
Francesco Dalena ◽  
Enrico Catizzone ◽  
Girolamo Giordano
Keyword(s):  
Acid Catalyst ◽  
Methanol Conversion ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Zeolite Catalysts ◽  
Hybrid Catalyst ◽  
Zeolite Structure ◽  
Precipitation Medium ◽  
Co Precipitation ◽  
New Evidence

The assessment of the catalytic performance of “hybrid” metal/zeolite catalysts (based on FER or MFI structure and CuZnZr metal complexes) in the methanol dehydration step to DME has been studied in this work. The results clearly show that there is an important effect of the interaction between metal and acid sites affecting the acid catalyst performances. Additionally, deactivation, studied by means of a Timo-on-Stream (TOS) test, was affected by the type of zeolite structure used for hybrid catalyst preparation. The decrease in DME selectivity can be attributed to the cooperation of metal and acid sites in the production of different compounds (mainly methyl formate and dimethoxy methane) converting methanol and DME. The presence of these compounds (indicating different reaction pathways active) was found to be dependent on the zeolite structure and on the type of co-precipitation medium (water or ethanol) used to prepare the hybrid catalyst.

scholarly journals The Influence of Process Conditions on the Chemical Composition of Pine Wood Catalytic Pyrolysis Oils

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
J. Pereira ◽  
F. A. Agblevor ◽  
S. H. Beis
Keyword(s):  
Sodium Hydroxide ◽  
Catalytic Pyrolysis ◽  
Zeolite Catalysts ◽  
Process Conditions ◽  
Pyrolysis Products ◽  
Pine Wood ◽  
Aldehydes And Ketones ◽  
Pyrolysis Oils ◽  
Long Chain ◽  
Sodium Hydroxide Treatment

Pine wood samples were used as model feedstock to study the properties of catalytic fast pyrolysis oils. The influence of two commercial zeolite catalysts (BASF and SudChem) and pretreatment of the pine wood with sodium hydroxide on pyrolysis products were investigated. The pyrolysis oils were first fractionated using column chromatography and characterized using GC-MS. Long chain aliphatic hydrocarbons, levoglucosan, aldehydes and ketones, guaiacols/syringols, and benzenediols were the major compounds identified in the pyrolysis oils. The catalytic pyrolysis increased the polycyclic hydrocarbons fraction. Significant decreases in phthalate derivatives using SudChem and long chain aliphatics using BASF catalyst were observed. Significant amounts of aromatic heterocyclic hydrocarbons and benzene derivatives were formed, respectively, using BASF and SudChem catalysts. Guaiacyl/syringyl and benzenediols derivatives were partly suppressed by the zeolite catalysts, while the sodium hydroxide treatment enriched phenolic derivatives. Zeolite catalyst and sodium hydroxide were employed together; they showed different results for each catalyst.

Role of zeolite structure on NO reduction with diesel fuel over Pt supported zeolite catalysts

2008 ◽  
Vol 111 (1-3) ◽  
pp. 488-492 ◽  
Author(s):  
Asima Sultana ◽  
Masaaki Haneda ◽  
Tadahiro Fujitani ◽  
Hideaki Hamada
Keyword(s):  
Diesel Fuel ◽  
No Reduction ◽  
Zeolite Catalysts ◽  
Zeolite Structure

ChemInform Abstract: Cracking of Long-Chain Alkyl Aromatics on USY Zeolite Catalysts.

ChemInform ◽  
2010 ◽  
Vol 23 (31) ◽  
pp. no-no
Author(s):  
A. CORMA ◽  
P. J. MIGUEL ◽  
A. V. ORCHILLES ◽  
G. S. KOERMER
Keyword(s):  
Zeolite Catalysts ◽  
Usy Zeolite ◽  
Long Chain

scholarly journals Dehydroaromatization of methane over noble metal loaded Mo/H-ZSM-5 zeolite catalysts

2021 ◽  
Author(s):  
Themba E. Tshabalala ◽  
Neil J. Coville ◽  
James A. Anderson ◽  
Michael S. Scurrell
Keyword(s):  
Comparative Study ◽  
Noble Metal ◽  
Methane Conversion ◽  
Catalytic Performance ◽  
Zeolite Catalysts ◽  
Product Selectivity ◽  
Total Reduction

AbstractDehydroaromatization of methane (MDA) reaction was investigated over platinum modified Mo/H-ZSM-5 catalysts which were pre-carbided at 750 °C. The influence of platinum on the catalytic performance and product selectivity of Mo/H-ZSM-5 catalysts for the MDA reaction at 700 °C were studied. The presence of platinum led to a slight decrease in methane conversion from 7.5 to 4.2%. Aromatic selectivities above 90% were obtained with catalysts containing low platinum loadings (0.5 and 1.0 wt.%), with benzene being the most prominent product. A decrease in coke selectivity and coke deposits was noted with the platinum modified Mo/H-ZSM-5 zeolite catalysts. A comparative study was performed to compare platinum, palladium and ruthenium promoted Mo/H-ZSM-5 zeolite catalysts with un-promoted Mo/H-ZSM-5. The ruthenium promoted catalyst proved to be superior in catalytic performance, with a higher methane conversion obtained than that found for platinum promoted and palladium promoted Mo/H-ZSM-5 catalysts. Benzene selectivity of about 60% was obtained for ruthenium and palladium promoted Mo/H- ZSM-5 catalysts and the total aromatic selectivity was maintained at 90%. TGA results showed a total reduction of 50% by weight of carbon deposited on the promoted Mo/H-ZSM-5 catalyst. Graphic abstract

Influence of the parent zeolite structure on chromium speciation and catalytic properties of Cr-zeolite catalysts in the ethylene ammoxidation

2012 ◽  
Vol 439-440 ◽  
pp. 88-100 ◽  
Author(s):  
F. Ayari ◽  
M. Mhamdi ◽  
T. Hammedi ◽  
J. Álvarez-Rodríguez ◽  
A.R. Guerrero-Ruiz ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Zeolite Catalysts ◽  
Chromium Speciation ◽  
Zeolite Structure
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