Highly active alumina for aldol condensation of acetone

1987 ◽  
Vol 34 (2) ◽  
pp. 255-259 ◽  
Author(s):  
Geng Zhang ◽  
Hideshi Hattori ◽  
Kozo Tanabe
Keyword(s):  
Aldol Condensation ◽  
Highly Active ◽  
Active Alumina

scholarly journals Chemoselective Reduction of Nitroarenes with Hydrazine over a Highly Active Alumina-Supported Cobalt Nanocatalyst

2019 ◽  
Vol 66 (3) ◽  
pp. 740-744
Author(s):  
Jalal Albadi ◽  
Heshmat Allah Samimi ◽  
Mehdi Jalali
Keyword(s):  
Highly Active ◽  
Active Alumina

scholarly journals Hydrotalcite-Supported Ag/Pd Bimetallic Nanoclusters Catalyzed Oxidation and One-Pot Aldol Reaction in Water

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1120
Author(s):  
Sangita Karanjit ◽  
Ayumu Tamura ◽  
Masaya Kashihara ◽  
Kazuki Ushiyama ◽  
Lok Kumar Shrestha ◽  
...  
Keyword(s):  
Aldol Condensation ◽  
Chemical Reduction ◽  
Recovery Process ◽  
Alcohol Oxidation ◽  
Significant Loss ◽  
One Pot ◽  
Unsaturated Ketones ◽  
Highly Active ◽  
Bimetallic Nanoclusters ◽  
Transmission Electron

A highly active hydrotalcite-supported Ag/Pd bimetallic nanocluster catalyst has been developed by a simple, easy and safe chemical reduction method. The catalyst was characterized by high-resolution transmission electron microscopy (HR-TEM), which revealed very small (3.2 ± 0.7 nm) nanoclusters with a narrow size distribution. The bimetallic Ag/Pd catalyst showed strong cooperation between Ag and Pd for the alcohol oxidation reaction. The developed catalyst provided an efficient and environmentally friendly method for alcohol oxidation and one-pot cross-aldol condensation in water. A broad scope of α,β-unsaturated ketones with good to excellent yields were obtained under very mild conditions. This catalytic system offers an easy preparation method with a simple recovery process, good activity and reusability of up to five cycles without significant loss in the catalytic activity.

XAFS Characterization of Highly Active Alumina-Supported Molybdenum Phosphide Catalysts (MoP/Al2O3) for Hydrotreating

2001 ◽  
Vol 105 (21) ◽  
pp. 4961-4966 ◽  
Author(s):  
S. T. Oyama ◽  
P. Clark ◽  
V. L. S. Teixeira da Silva ◽  
E. J. Lede ◽  
F. G. Requejo
Keyword(s):  
Highly Active ◽  
Active Alumina ◽  
Molybdenum Phosphide

scholarly journals Preparation of Highly Active Alumina-Pillared Clay Montmorillonite-Supported Platinum Catalyst for Hydrodesulfurization

2009 ◽  
Vol 52 (6-7) ◽  
pp. 765-771 ◽  
Author(s):  
Yasuharu Kanda ◽  
Hiroyuki Iwamoto ◽  
Takao Kobayashi ◽  
Yoshio Uemichi ◽  
Masatoshi Sugioka
Keyword(s):  
Platinum Catalyst ◽  
Pillared Clay ◽  
Highly Active ◽  
Active Alumina ◽  
Supported Platinum ◽  
Supported Platinum Catalyst

scholarly journals Waste Seashells as a Highly Active Catalyst for Cyclopentanone Self-Aldol Condensation

Catalysts ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 661 ◽  
Author(s):  
Sheng ◽  
Xu ◽  
Wang ◽  
Li ◽  
Jia ◽  
...  
Keyword(s):  
High Performance ◽  
Aldol Condensation ◽  
Solid Base ◽  
X Ray Diffraction ◽  
Solid Base Catalysts ◽  
Base Catalysts ◽  
Highly Active ◽  
Activity Sequence ◽  
Waste Shell ◽  
Temperature Programmed

For the first time, waste-seashell-derived CaO catalysts were used as high-performance solid base catalysts for cyclopentanone self-condensation, which is an important reaction in bio-jet fuel or perfume precursor synthesis. Among the investigated seashell-derived catalysts, Scapharca Broughtonii-derived CaO catalyst (S-shell-750) exhibited the highest dimer yield (92.1%), which was comparable with commercial CaO (88.2%). The activity sequence of different catalysts was consistent with the CaO purity sequence and contact angle sequence. X-ray diffraction (XRD) results showed that CaCO3 in waste shell were completely converted to CaO after calcination at 750 °C or above for 4 h. CO2 temperature-programmed desorption (CO2-TPD) results indicate that both the amount and strength of base sites increase significantly when the calcination temperature climbs to 750 °C. Therefore, we can attribute the excellent performance of S-shell-750/850/950 catalysts to the higher CaO content, relatively low hydrophilicity, and stronger acidity and basicity of this catalyst. This study developed a new route for waste shell utilization in bio-derived ketone aldol condensation.

Preparation of Ga2O3 Doped Sulfonated Tin Oxides as a Highly Active and Recyclable Heterogeneous Solid Acid Catalyst for Aldol Reactions

2019 ◽  
Vol 19 (6) ◽  
pp. 3658-3662
Author(s):  
Dewei Zhai ◽  
Changyan Cao ◽  
Bin Shao ◽  
Dong Liu ◽  
Weiguo Song
Keyword(s):  
Tin Oxide ◽  
Aldol Condensation ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Acid Sites ◽  
Oxide Catalysts ◽  
Aldol Reactions ◽  
Solid Catalyst ◽  
Gravimetric Analysis ◽  
Highly Active

Ga2O3 doped sulfonated tin oxide catalysts were prepared via co-condensation method in ethanol solvent, followed by sulfonation and calcination. The samples were characterized by isothermal nitrogen adsorption/desorption, powder X-ray diffraction (XRD), thermal gravimetric analysis (TG), Raman spectra and DRIFT spectra. The number of acid sites on the catalysts was measured with the potentiometric titration of butyl amine. The results showed that the addition of small amounts of Ga2O3 to sulfonated tin oxide resulted in an enhanced acid site density, which makes Ga2O3 doped sulfonated tin oxide catalysts highly active for aldol reactions. The catalyst containing 1.5% Ga2O3 exhibited much higher activity than those of SO42−/SnO2, SO42−/ZrO2 and H3PO4 in aldol condensation of prenal and prenol for citral precursor, which is a important in fragrance industry. Besides the high activity, the catalyst also exhibited good recyclability, making 1.5% GST an efficient and promising solid catalyst for aldol reactions.

Characterization of Chemical Impurities in Glutaraldehyde

1975 ◽  
Vol 33 ◽  
pp. 620-621
Author(s):  
B. J. Grenon ◽  
A. J. Tousimis
Keyword(s):  
Glutaric Acid ◽  
Spectroscopic Analysis ◽  
Aldol Condensation ◽  
Condensation Product ◽  
Amorphous Solid ◽  
Water Soluble ◽  
Impurity Component ◽  
Chemical Impurities ◽  
Soluble Liquid

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.

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