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

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

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.

Comparison of the properties and catalytic activity of commercially and laboratory prepared Mg/Al mixed oxides in aldol condensation of cyclohexanone with furfural

2018 ◽  
Vol 126 (1) ◽  
pp. 219-235 ◽  
Author(s):  
David Kadlec ◽  
Zdeněk Tišler ◽  
Romana Velvarská ◽  
Lenka Pelíšková ◽  
Uliana Akhmetzyanova
Keyword(s):  
Catalytic Activity ◽  
Mixed Oxides ◽  
Aldol Condensation

The role of ZnO in the catalytic behaviour of Zn-Al mixed oxides in aldol condensation of furfural with acetone

2020 ◽  
Author(s):  
Lada Dubnová ◽  
Lucie Smoláková ◽  
Oleg Kikhtyanin ◽  
Jaroslav Kocík ◽  
David Kubička ◽  
...  
Keyword(s):  
Mixed Oxides ◽  
Aldol Condensation ◽  
Catalytic Behaviour

Aldol condensation of furfural and acetone over MgAl layered double hydroxides and mixed oxides

2014 ◽  
Vol 223 ◽  
pp. 138-147 ◽  
Author(s):  
Lukáš Hora ◽  
Vendula Kelbichová ◽  
Oleg Kikhtyanin ◽  
Oleg Bortnovskiy ◽  
David Kubička
Keyword(s):  
Layered Double Hydroxides ◽  
Mixed Oxides ◽  
Aldol Condensation ◽  
Double Hydroxides

scholarly journals Influences of Magnesium Content in Rehydrated Mixed Oxides on Furfural Conversion

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1484
Author(s):  
Kocík Jaroslav ◽  
Kolena Jiří ◽  
Akhmetzyanova Uliana ◽  
Tišler Zdeněk
Keyword(s):  
Layered Structure ◽  
Atmospheric Pressure ◽  
Mixed Oxides ◽  
Aldol Condensation ◽  
Glass Batch ◽  
Batch Reactor ◽  
Magnesium Content ◽  
Molar Ratio ◽  
High Basicity ◽  
Fe Catalysts

In this study, Mg-Fe catalysts with various molar ratio (Mg/Fe 1:1-10:1), prepared by calcination and subsequent rehydration of hydrotalcite structures, were characterized, tested and evaluated as suitable catalysts for the aldol condensation of furfural with acetone. XRD analyses confirmed that the layered structure was completely restored by rehydration in the catalysts with Mg:Fe molar ratio 3:1 and 4:1. TPD-CO2 showed that the catalysts of this molar ratio had the highest basicity. Rehydrated Mg-Fe catalysts were tested in aldol condensation carried out in a glass batch reactor at 60 °C, atmospheric pressure, 2 wt% of catalyst and acetone/furfural molar ratio 10:1. The catalysts with Mg/Fe molar ratio of 3:1 and 4:1 showed total furfural conversion. As high basicity causes a high activity of the catalyst, our results suggest that the rehydrated mixed oxides with molar ratio 3 to 4:1 were promising new catalysts for the aldol condensation of furfural with acetone.

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