Effect of Oxalic Acid on the Structure and Catalytic Performance of Sb-V-O Catalyst for Propane Ammoxidation

2013 ◽  
Vol 33 (7) ◽  
pp. 1203-1208
Author(s):  
Guojun WANG ◽  
Yun GUO ◽  
Guanzhong LU
Keyword(s):  
Oxalic Acid ◽  
Catalytic Performance ◽  
Propane Ammoxidation

scholarly journals Preparation of pod-shaped TiO 2 and Ag@TiO 2 nano burst tubes and their photocatalytic activity

2019 ◽  
Vol 6 (9) ◽  
pp. 191019 ◽  
Author(s):  
Shang Wang ◽  
Zhaolian Han ◽  
Tingting Di ◽  
Rui Li ◽  
Siyuan Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Oxalic Acid ◽  
Ultraviolet Light ◽  
Photoelectron Spectroscopy ◽  
Degradation Process ◽  
Catalytic Performance ◽  
Tetrabutyl Titanate ◽  
Order Kinetic ◽  
X Ray

The pod-shaped TiO 2 nano burst tubes (TiO 2 NBTs) were prepared by the combination of electrospinning and impregnation calcination with oxalic acid (H 2 C 2 O 4 ), polystyrene (PS) and tetrabutyl titanate. The silver nanoparticles (AgNPs) were loaded onto the surface of TiO 2 NBTs by ultraviolet light reduction method to prepare pod-shaped Ag@TiO 2 NBTs. In this work, we analysed the effect of the amount of oxalic acid on the cracking degree of TiO 2 NBTs; the effect of the concentration of AgNO 3 solution on the particle size and loading of AgNPs on the surface of TiO 2 NBTs. Scanning electron microscopy and transmission electron microscopy investigated the surface morphology of samples. X-ray diffraction and X-ray photoelectron spectroscopy characterized the structure and composition of samples. Rhodamine B (RhB) solution was used to evaluate the photocatalytic activity of pod-shaped TiO 2 NBTs and Ag@TiO 2 NBTs. The results showed that TiO 2 NBTs degraded 91.0% of RhB under ultraviolet light, Ag@TiO 2 NBTs degraded 95.5% under visible light for 75 and 60 min, respectively. The degradation process of both samples was consistent with the Langmuir–Hinshelwood first-order kinetic equation. Therefore, the catalytic performance of the sample is: Ag@TiO 2 NBTs > TiO 2 NBTs > TiO 2 nanotubes.

A MAS NMR and DRIFT study of the Ga species in Ga/H-ZSM5 catalysts and their effect on propane ammoxidation

2005 ◽  
Vol 83 (6-7) ◽  
pp. 574-580 ◽  
Author(s):  
Prem Pal ◽  
Juliette Quartararo ◽  
Sharifah B Abd Hamid ◽  
Eric G Derouane ◽  
Jacques C Védrine ◽  
...  
Keyword(s):  
Main Product ◽  
External Surface ◽  
Catalytic Performance ◽  
Mas Nmr ◽  
Propane Ammoxidation ◽  
Bifunctional Mechanism ◽  
Propane Activation ◽  
Cationic Exchange ◽  
Zeolite Crystals

71Ga, 27Al, and 29Si MAS NMR and DRIFT spectroscopies were used to characterize the state of gallium in Ga/H-ZSM5 catalysts tested for their ability to catalyse the ammoxidation of propane. Ga species were observed in two different possible environments: octahedrally coordinated gallium in small Ga2O3 particles at the external surface of the zeolite crystals, octahedrally coordinated gallium in GaO(OH) or related species, and tetrahedrally coordinated gallium in cationic-exchange positions inside the zeolite. Redox (H2–O2) cycles promote the migration of gallium from the GaO(OH) or Ga2O3 species at the external surface of the zeolite crystals to cationic-exchange sites within the zeolite channels. The redox treatment definitely had a beneficial effect on its catalytic performance for the ammoxidation of propane, which is known to occur via a bifunctional mechanism. The main product was acetonitrile at high Ga and Al contents while acrylonitrile was also observed as a side product at high Ga and low Al contents.Key words: ZSM5, MFI, in situ studies, MAS NMR, DRIFT, propane activation, ammoxidation.

Hydroisomerization of Biomass Derived n-Hexadecane Towards Diesel Pool: Effect of Selective Removal External Surface Sites from Pt/ZSM-22

2016 ◽  
Vol 14 (1) ◽  
pp. 155-165 ◽  
Author(s):  
Abhijeet H. Thaker ◽  
Mathew John ◽  
Kishore Kumar ◽  
Mahesh W. Kasture ◽  
Snehalkumar Parmar ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Active Sites ◽  
External Surface ◽  
Space Velocity ◽  
Product Distribution ◽  
Catalytic Performance ◽  
Selective Removal ◽  
Cold Flow ◽  
External Site ◽  
Kinetics Of

AbstractInfluence of dealumination of zeolite ZSM-22 (Si/Al ratio of 45) by treating it with oxalic acid on its catalytic performance in n-hexadecane hydroisomerization reaction was studied. This reaction is an attempt in the direction of green and sustainable source of diesel via improving the cold-flow properties of deoxygenated vegetable oils. Pt (0.5 wt%) on ZSM-22 treated with 1 M oxalic acid afforded highest yields of the mono-branched paraffins. This improved is attributed to selective removal of active sites on external surface of zeolite crystals (responsible for undesired cracking reactions) using the bulkier dealuminating agent, oxalic acid. Thus, pore-mouth key-lock mechanism was brought to play the role to cause high selectivity to mono-branched isomers. Preferential external site deactivation was inferred from mesitylene cracking results. Effects of operating parameters such as temperature, and space velocity on product distribution also were studied. Also, kinetics of the reactions involved too has been in brief reported.

scholarly journals Synthesis, characterization and catalytic testing of MCM-22 derived catalysts for n-hexane cracking

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ali Ahmad ◽  
Salman Raza Naqvi ◽  
Muhammad Rafique ◽  
Habib Nasir ◽  
Ali Sarosh
Keyword(s):  
Oxalic Acid ◽  
Hydrothermal Method ◽  
High Temperatures ◽  
Reaction Temperature ◽  
Catalytic Cracking ◽  
Product Distribution ◽  
Catalytic Performance ◽  
Temperature Range ◽  
Novel Materials ◽  
Diffusion Limitations

AbstractLayered zeolites and their delaminated structures are novel materials that enhance the catalytic performance of catalysts by addressing diffusion limitations of the reactant molecules. n-Hexane catalytic cracking was observed over MCM-22 layered zeolite and its derivative structures over the temperature range of 450–650 °C for the production of olefins. MCM-22, H-MCM-22, and ITQ-2 zeolites were prepared by the hydrothermal method. Oxalic acid was used as a dealuminating reagent to obtain H-MCM-22 with various Si/Al ratios ranging from 09–65. The prepared samples were characterized by XRD, SEM, TGA, and BET. The cracking of n-hexane was carried out by Pyro/GC–MS. It was observed that the selectivity for olefins was improved by increasing the Si/Al ratio. H-MCM-22–10% produced the highest relative olefinic concentration of 68% as compared to other dealuminated structures. Moreover, the product distribution showed that higher reaction temperature is favorable to produce more olefins. Furthermore, a comparison between ITQ-2 and MCM-22 derived structures showed that ITQ-2 is more favorable for olefins production at high temperatures. The concentration of relative olefins was increased up to 80% over ITQ-2 at 650 °C.

Mechanistic evaluation of ferrite AFe2O4 (A = Co, Ni, Cu, and Zn) catalytic performance in oxalic acid ozonation

2017 ◽  
Vol 547 ◽  
pp. 60-68 ◽  
Author(s):  
Fengzhen Zhang ◽  
Chaohai Wei ◽  
Kaiyi Wu ◽  
Hongtao Zhou ◽  
Yun Hu ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Catalytic Performance ◽  
Cu And Zn

scholarly journals The control of catalytic performance of rutile-type Sn/V/Nb/Sb mixed oxides, catalysts for propane ammoxidation to acrylonitrile

2008 ◽  
Vol 138 (1-2) ◽  
pp. 97-103 ◽  
Author(s):  
Elena Arcozzi ◽  
Nicola Ballarini ◽  
Fabrizio Cavani ◽  
Massimo Cimini ◽  
Carlo Lucarelli ◽  
...  
Keyword(s):  
Mixed Oxides ◽  
Catalytic Performance ◽  
Propane Ammoxidation

Enhancement of Catalytic Performance of H-Clinoptilolite in Toluene Abatement from Polluted Air via Controlled Dealumination Method

2018 ◽  
Vol 16 (5) ◽  
Author(s):  
Naser Ghasemian ◽  
Ali Reza Yousefi
Keyword(s):  
Oxalic Acid ◽  
Chemical Modification ◽  
Treatment Period ◽  
Acid Site ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Total Oxidation ◽  
Maximum Conversion ◽  
First Time ◽  
Mild Acid

AbstractIn this study, the effect of clinoptilolite dealumination on the total oxidation of toluene was reported for the first time. To avoid excess decrease of catalyst crystallinity, chemical modification of zeolite was carried out using a mild acid like oxalic acid. The catalysts were characterized by XRD, XRF, SEM, BET and TPD analyses. It was found that dealumination resulted in a significant enhancement of toluene conversion when 0.050 M acid oxalic was used for a treatment period of 2 h. Dealumination substantially changed the distribution of the concentration of acid sites of different strength and increased the surface area and porosity, so that the temperature corresponding to the maximum conversion shifts around 50 °C towards lower temperatures (in case of CLP 050). The effect of dealumination on the activity of the zeolite samples and the total oxidation of toluene was discussed in terms of Si/Al ratio, crystallinity, distribution of acid site strength and textural characteristics of the samples.

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