Mg−Al Mixed Oxides as Highly Active Acid−Base Catalysts for Cycloaddition of Carbon Dioxide to Epoxides

1999 ◽  
Vol 121 (18) ◽  
pp. 4526-4527 ◽  
Author(s):  
Kazuya Yamaguchi ◽  
Kohki Ebitani ◽  
Tomoko Yoshida ◽  
Hisao Yoshida ◽  
Kiyotomi Kaneda
Keyword(s):  
Carbon Dioxide ◽  
Mixed Oxides ◽  
Acid Base ◽  
Base Catalysts ◽  
Highly Active

ChemInform Abstract: Mg-Al Mixed Oxides as Highly Active Acid-Base Catalysts for Cycloaddition of Carbon Dioxide to Epoxides.

ChemInform ◽  
2010 ◽  
Vol 30 (36) ◽  
pp. no-no
Author(s):  
Kazuya Yamaguchi ◽  
Kohki Ebitani ◽  
Tomoko Yoshida ◽  
Hisao Yoshida ◽  
Kiyotomi Kaneda
Keyword(s):  
Carbon Dioxide ◽  
Mixed Oxides ◽  
Acid Base ◽  
Base Catalysts ◽  
Highly Active

Fabrication of Amine and Zirconia on MCM-41 as Acid-Base Catalysts for the Fixation of Carbon Dioxide

ChemCatChem ◽  
2017 ◽  
Vol 9 (21) ◽  
pp. 4105-4111 ◽  
Author(s):  
Vitthal B. Saptal ◽  
Binita Nanda ◽  
Kulamani M. Parida ◽  
Bhalchandra M. Bhanage
Keyword(s):  
Carbon Dioxide ◽  
Acid Base ◽  
Base Catalysts ◽  
Fixation Of Carbon Dioxide ◽  
Mcm 41

scholarly journals Synthesis of Chalcone Using LDH/Graphene Nanocatalysts of Different Compositions

2019 ◽  
Vol 3 (1) ◽  
pp. 29 ◽  
Author(s):  
Mayra Álvarez ◽  
Dana Crivoi ◽  
Francesc Medina ◽  
Didier Tichit
Keyword(s):  
Active Sites ◽  
Mixed Oxides ◽  
Catalytic Properties ◽  
Condensation Reaction ◽  
Nanocomposite Materials ◽  
Acid Base ◽  
Basic Sites ◽  
Base Catalysts ◽  
Reduced Graphene ◽  
Double Hydroxides

Layered double hydroxides (LDH) or their derived mixed oxides present marked acid-base properties useful in catalysis, but they are generally agglomerated, inducing weak accessibility to the active sites. In the search for improving dispersion and accessibility of the active sites and for controlling the hydrophilic/hydrophobic balance in the catalysts, nanocomposite materials appear among the most attractive. In this study, a series of nanocomposites composed of LDH and reduced graphene oxide (rGO), were successfully obtained by direct coprecipitation and investigated as base catalysts for the Claisen–Schmidt condensation reaction between acetophenone and benzaldehyde. After activation, the LDH-rGO nanocomposites exhibited improved catalytic properties compared to bare LDH. Moreover, they reveal great versatility to tune the selectivity through their composition and the nature or the absence of solvent. This is due to the enhanced basicity of the nanocomposites as the LDH content increases which is assigned to the higher dispersion of the nanoplatelets in comparison to bulk LDH. Lewis-type basic sites of higher strength and accessibility are thus created. The nature of the solvent mainly acts through its acidity able to poison the basic sites of the nanocatalysts.

scholarly journals On the Effect of the M3+ Origin on the Properties and Aldol Condensation Performance of MgM3+ Hydrotalcites and Mixed Oxides

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 992
Author(s):  
Valeriia Korolova ◽  
Oleg Kikhtyanin ◽  
Martin Veselý ◽  
Dan Vrtiška ◽  
Iva Paterová ◽  
...  
Keyword(s):  
Mixed Oxides ◽  
Aldol Condensation ◽  
Catalytic Performance ◽  
Atomic Weight ◽  
Solid Base ◽  
Acid Base ◽  
Advanced Biofuels ◽  
Solid Base Catalysts ◽  
Base Catalysts ◽  
The Relationship

Hydrotalcites (HTCs) are promising solid base catalysts to produce advanced biofuels by aldol condensation. Their main potential lies in the tunability of their acid-base properties by varying their composition. However, the relationship between the composition of hydrotalcites, their basicity, and their catalytic performance has not yet been fully revealed. Here, we investigate systematically the preparation of HTCs with the general formula of Mg6M3+2(OH)16CO3·4H2O, where M3+ stands for Al, Ga, Fe, and In, while keeping the Mg/M3+ equal to 3. We use an array of analytical methods including XRD, N2 physisorption, CO2-TPD, TGA-MS, FTIR-ATR, and SEM to assess changes in the properties and concluded that the nature of M3+ affected the HTC crystallinity. We show that the basicity of the HTC-derived mixed oxides decreased with the increase in atomic weight of M3+, which was reflected by decreased furfural conversion in its aldol condensation with acetone. We demonstrate that all MgM3+ mixed oxides can be fully rehydrated, which boosted their activity in aldol condensation. Taking all characterization results together, we conclude that the catalytic performance of the rehydrated HTCs is determined by the “host” MgO component, rather than the nature of M3+.

Effect of lanthanide ion doping on Mg−Al mixed oxides as active acid−base catalysts for fatty acid ethyl ester synthesis

2019 ◽  
Vol 133 ◽  
pp. 367-372 ◽  
Author(s):  
Jessika de Souza Rossi ◽  
Olavo Micali Perrone ◽  
Marcos Rechi Siqueira ◽  
Diogo Paschoalini Volanti ◽  
Eleni Gomes ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Ethyl Ester ◽  
Mixed Oxides ◽  
Acid Ethyl Ester ◽  
Fatty Acid Ethyl Ester ◽  
Ester Synthesis ◽  
Acid Base ◽  
Lanthanide Ion ◽  
Base Catalysts ◽  
Ion Doping
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