Performance of basic mixed oxides for aqueous-phase 5-hydroxymethylfurfural-acetone aldol condensation

2017 ◽  
Vol 201 ◽  
pp. 221-231 ◽  
Author(s):  
Jennifer Cueto ◽  
Laura Faba ◽  
Eva Díaz ◽  
Salvador Ordóñez
Keyword(s):  
Aqueous Phase ◽  
Mixed Oxides ◽  
Aldol Condensation

Aqueous-phase furfural-acetone aldol condensation over basic mixed oxides

2012 ◽  
Vol 113-114 ◽  
pp. 201-211 ◽  
Author(s):  
Laura Faba ◽  
Eva Díaz ◽  
Salvador Ordóñez
Keyword(s):  
Aqueous Phase ◽  
Mixed Oxides ◽  
Aldol Condensation

Controllable self-aldol condensation of cyclopentanone over MgO-ZrO2 mixed oxides: Origin of activity & selectivity

2016 ◽  
Vol 81 ◽  
pp. 33-36 ◽  
Author(s):  
Decheng Liang ◽  
Guozhu Li ◽  
Yanhong Liu ◽  
Jinmeng Wu ◽  
Xiangwen Zhang
Keyword(s):  
Mixed Oxides ◽  
Aldol Condensation

scholarly journals Aldol Condensation of Cyclohexanone and Furfural in Fixed-Bed Reactor

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1068
Author(s):  
Zdeněk Tišler ◽  
Pavla Vondrová ◽  
Kateřina Hrachovcová ◽  
Kamil Štěpánek ◽  
Romana Velvarská ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Heterogeneous Catalysts ◽  
Mixed Oxides ◽  
Aldol Condensation ◽  
Condensation Reaction ◽  
Catalyst Activity ◽  
Fixed Bed ◽  
Chemical Properties ◽  
Fixed Bed Reactor ◽  
Molar Ratio

Aldol condensation reaction is usually catalysed using homogeneous catalysts. However, the heterogeneous catalysis offers interesting advantages and the possibility of cleaner biofuels production. Nowadays, one of the most used kinds of heterogeneous catalysts are hydrotalcites, which belong to a group of layered double hydroxides. This paper describes the aldol condensation of cyclohexanone (CH) and furfural (F) using Mg/Al mixed oxides and rehydrated mixed oxides in order to compare the catalyst activity after calcination and rehydration, as well as the possibility of its regeneration. The catalysts were synthesized by calcination and subsequent rehydration of the laboratory-prepared and commercial hydrotalcites, with Mg:Al molar ratio of 3:1. Their structural and chemical properties were determined by several analytical methods (inductively coupled plasma analysis (ICP), X-ray diffraction (XRD), diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), specific surface area (BET), thermogravimetric analysis (TGA), temperature programmed desorption (TPD)). F-CH aldol condensation was performed in a continuous fixed-bed reactor at 80 °C, CH:F = 5:1, WHSV 2 h−1. The rehydrated laboratory-prepared catalysts showed a 100% furfural conversion for more than 55 h, in contrast to the calcined ones (only 24 h). The yield of condensation products FCH and F2CH was up to 68% and 10%, respectively. Obtained results suggest that Mg/Al mixed oxides-based heterogeneous catalyst is suitable for use in the aldol condensation reaction of furfural and cyclohexanone in a fixed-bed reactor, which is an interesting alternative way to obtain biofuels from renewable sources.

scholarly journals Robust Ruthenium Catalysts Supported on Mesoporous Cyclodextrin-Templated TiO2-SiO2 Mixed Oxides for the Hydrogenation of Levulinic Acid to γ-Valerolactone

2021 ◽  
Vol 22 (4) ◽  
pp. 1721
Author(s):  
Cédric Decarpigny ◽  
Sébastien Noël ◽  
Ahmed Addad ◽  
Anne Ponchel ◽  
Eric Monflier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aqueous Phase ◽  
Levulinic Acid ◽  
Mixed Oxides ◽  
Building Blocks ◽  
Strong Impact ◽  
Pore Characteristics ◽  
Assembly Method ◽  
Transmission Electron

In this paper, we present a versatile template-directed colloidal self-assembly method for the fabrication in aqueous phase of composition-tuned mesoporous RuO2@TiO2-SiO2 catalysts. Randomly methylated β-cyclodextrin/Pluronic F127 supramolecular assemblies were used as soft templates, TiO2 colloids as building blocks, and tetraethyl orthosilicate as a silica source. Catalysts were characterized at different stages of their synthesis using dynamic light scattering, N2-adsorption analysis, powder X-ray diffraction, temperature programmed reduction, high-resolution transmission electron microscopy, high-angle annular bright-field and dark-field scanning transmission electron microscopy, together with EDS elemental mapping. Results revealed that both the supramolecular template and the silica loading had a strong impact on the pore characteristics and crystalline structure of the mixed oxides, as well as on the morphology of the RuO2 nanocrystals. Their catalytic performance was then evaluated in the aqueous phase hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) under mild conditions (50 °C, 50 bar H2). Results showed that the cyclodextrin-derived catalyst displayed almost quantitative LA conversion and 99% GVL yield in less than one hour. Moreover, this catalyst could be reused at least five times without loss of activity. This work offers an effective approach to the utilization of cyclodextrins for engineering the surface morphology of Ru nanocrystals and pore characteristics of TiO2-based materials for catalytic applications in hydrogenation reactions.

scholarly journals Aqueous-phase ketonization of acetic acid over Zr/Mn mixed oxides

AIChE Journal ◽  
2017 ◽  
Vol 63 (7) ◽  
pp. 2958-2967 ◽  
Author(s):  
Kejing Wu ◽  
Mingde Yang ◽  
Yu Chen ◽  
Weihua Pu ◽  
Husheng Hu ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Aqueous Phase ◽  
Mixed Oxides

scholarly journals In situ ATR-IR studies in aqueous phase reforming of hydroxyacetone on Pt/ZrO2 and Pt/AlO(OH) catalysts: The role of aldol condensation

2018 ◽  
Vol 232 ◽  
pp. 454-463 ◽  
Author(s):  
Kamila Koichumanova ◽  
Anna Kaisa K. Vikla ◽  
Remedios Cortese ◽  
Francesco Ferrante ◽  
K. Seshan ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Aldol Condensation ◽  
Aqueous Phase Reforming ◽  
Ir Studies

Aqueous Phase Aldol Condensation of Formaldehyde and Acetone on Anatase TiO 2 (101) Surface: A Theoretical Investigation

ChemCatChem ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1220-1229 ◽  
Author(s):  
Yuntao Zhao ◽  
Xinli Zhu ◽  
Hua Wang ◽  
Jinyu Han ◽  
Donghai Mei ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Theoretical Investigation ◽  
Aldol Condensation
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