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.

scholarly journals Supported hydrotalcites as highly active solid base catalysts

2005 ◽  
pp. 3977 ◽  
Author(s):  
Ferry Winter ◽  
A. Jos van Dillen ◽  
Krijn P. de Jong
Keyword(s):  
Solid Base ◽  
Solid Base Catalysts ◽  
Base Catalysts ◽  
Highly Active

scholarly journals Solid base catalysts derived from Ca–Al–X (X = F−, Cl− and Br−) layered double hydroxides for methanolysis of propylene carbonate

RSC Advances ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. 785-791 ◽  
Author(s):  
Yunhui Liao ◽  
Feng Li ◽  
Yanfeng Pu ◽  
Feng Wang ◽  
Xin Dai ◽  
...  
Keyword(s):  
Propylene Carbonate ◽  
Layered Double Hydroxides ◽  
Dimethyl Carbonate ◽  
Solid Base ◽  
Solid Base Catalysts ◽  
Base Catalysts ◽  
Highly Active ◽  
Double Hydroxides

The CA-F− catalyst modified with Al3+ and F− was highly active and recyclable for dimethyl carbonate synthesis.

Greener Methodology: An Aldol Condensation of an Unprotected C-Glycoside with Solid Base Catalysts

2018 ◽  
Vol 6 (6) ◽  
pp. 7810-7817 ◽  
Author(s):  
Tamara M. de Winter ◽  
Laurène Petitjean ◽  
Hanno C. Erythropel ◽  
Magali Moreau ◽  
Julien Hitce ◽  
...  
Keyword(s):  
Aldol Condensation ◽  
Solid Base ◽  
Solid Base Catalysts ◽  
Base Catalysts

Formation of Methyl Acrylate from Methyl Acetate and Formaldehyde Condensation over Solid Base Catalysts

2012 ◽  
Vol 629 ◽  
pp. 376-380 ◽  
Author(s):  
Ya Nan Wang ◽  
Qun Long Wang ◽  
Huan Hui Chen ◽  
Jia Lei Zhang ◽  
Zhi Rong Zhu
Keyword(s):  
Acrylic Acid ◽  
Vapor Phase ◽  
Methyl Acrylate ◽  
Methyl Acetate ◽  
Aldol Condensation ◽  
Solid Base ◽  
Base Property ◽  
Support Materials ◽  
Solid Base Catalysts ◽  
Base Catalysts

The vapor-phase aldol condensation of methyl acetate (MeOAC) with formaldehyde (HCHO) to form methyl acrylate was investigated over solid base catalysts. A variety of solid base catalysts were prepared by loading Cs2O over SiO2 or Al2O3 as the support materials. The properties of the solid base catalysts were characterized by XRD, BET and CO2-TPD. The results of the vapor-phase aldol condensation indicated that SiO2 and Al2O3 modified with Cs2O showed high conversation of methyl acetate and high selectivity of methyl acrylate. 22.6% conversation of methyl acetate and 16.5% yield of acrylic acid and methyl acrylate were obtained over Cs-Al2O3. In addition, Cs-SiO2 exhibited about 42% selectivity to methyl acetate. The high yield of acrylic acid and methyl acrylate is attributed to the high base property of catalysts.

scholarly journals Supported Hydrotalcites as Highly Active Solid Base Catalysts.

ChemInform ◽  
2005 ◽  
Vol 36 (51) ◽  
Author(s):  
Ferry Winter ◽  
A. Jos van Dillen ◽  
Krijn P. de Jong
Keyword(s):  
Solid Base ◽  
Solid Base Catalysts ◽  
Base Catalysts ◽  
Highly Active

Preparation of MgAlY-LDO Solid Base Catalysts and their Catalytic Performance on the Synthesis of Isophorone via Acetone Condensation

2012 ◽  
Vol 550-553 ◽  
pp. 424-428 ◽  
Author(s):  
Jian Jie Zhang ◽  
Zi Li Liu ◽  
Zu Zeng Qin ◽  
Yan Liu ◽  
Qi Ying Wang ◽  
...  
Keyword(s):  
Layer Structure ◽  
Catalytic Performance ◽  
Solid Base ◽  
Doping Amount ◽  
Strong Base ◽  
Solid Base Catalysts ◽  
Base Catalysts ◽  
Al Composite ◽  
Temperature Programmed ◽  
Acetone Condensation

Mg-Al composite oxide (MgAlY-LDO) solid base catalysts were prepared via the coprecipitation method, followed by calcinations at high temperatures. Isophorone synthesis from acetone condensation was also investigated. The catalysts were characterized via X-ray diffraction analysis, Fourier transform infrared spectroscopy, CO2 temperature-programmed desorption, and Brunauer-Emmett-Teller analysis. After doping with Y, the MgAl-LDO showed higher catalytic activity at a reaction temperature of 300 °C, 100 kPa and WHSV 6.3 h-1. Furthermore, the conversion of acetone and the selectivity of isophorone increased from 17.8% and 11.0% to 37.5% and 58.7%, respectively. These results indicate that the basicity of MgAlY-LDO as well as the number of its strong base centers increased after Y doping. The pore volume and size of MgAlY-LDO increased because of the increased hydrotalcite layer space caused by the big Y3+ ion. However, the crystal structure of hydrotalcite was remained. Y2O3 was evenly dispersed in MgAlY-LDO at low Y doping amounts. As the doping amount increased, the layer structure of hydrotalcite became distorted, thereby affecting the crystallinity of the hydrotalcite. Some Y3+ ions emerged from the Mg2+ lattice after doping with a high Y3+ concentration.

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