Evaluation of the Catalytic Activity of Metal Phosphates and Related Oxides in the Ketonization of Propionic Acid

Abstract

In recent years, the upgrading of lignocellulose bio-oils from fast-pyrolysis by means of ketonization has emerged as a frontier research domain to produce a new generation of biofuels. Propionic acid (PA) ketonization is extensively investigated as a model reaction over metal oxides, but the activity of other materials, such as metal phosphates, is mostly unknown. Therefore, PA ketonization was preliminarily investigated in the gas phase over both phosphates and oxides of Al, Zr, and La. Their catalytic activity was correlated to the physicochemical properties of the materials characterized by means of XRD, XRF, BET N2 porosimetry, and CO2- and NH3-TPD. Noteworthy, monoclinic ZrO2 proved to be the most promising candidate for the target reaction, leading to a 3-pentanone productivity as high as 5.6 h−1 in the optimized conditions. This value is higher than most of those reported for the same reaction in both the academic and patent literature.

Gas-phase oxidative dehydrogenation of long chain alkenols for the production of key fragrance ingredients: from Rosalva isomers to Costenal analogues

“…The presence of DA among the reaction products was explained by the consecutive oxidation of OPA (Scheme 3, reaction c), which was fostered by harsher reaction conditions. Then, the resulting DA underwent a ketonization reaction 80 forming the symmetric C 19 ketone NDD (Scheme 3, reaction e); in agreement with previous results 43,80 the ketonization was particularly favoured at 350 °C and DA were quantitatively transformed into NDD. Finally, the C 20 aldehyde ODT was formed by the aldol condensation of OPA with itself (Scheme 3, reaction d), which was fostered by an increase of the contact time ( e.g.…”

An innovative catalytic pathway for the synthesis of acyl furans: the cross-ketonization of methyl 2-furoate with carboxylic acids

“…Ceria (CeO 2 ) is a commercial reference material (Rhodia Actalys HAS 5) and was calcined in air at a heating rate of 5 °C min −1 up to 400 °C for 3 hours before use. Zirconia (ZrO 2 ) was synthesized by means of precipitation, adapting a method reported elsewhere; 6 ceria–zirconia (Ce/Zr/O) was synthesized adapting the method used for the synthesis of ZrO 2 . A more detailed description of catalysts’ preparation can be found in the ESI †…”

Supported rhenium catalysts for the hydrogenation of levulinic acid derivatives: limits and potential

“…2,3 For instance, the pyrolysis of LCB can yield a bio oil containing carboxylic acids that can be upgraded to gasoline by means of a ketonization/hydrotreating process. 4 Alternatively, LCB can be used to produce several signicant building blocks such as syngas (by means of gasication), methanol (from syngas), ethanol (by glucose fermentation), and ethylene (by ethanol dehydration). These molecules can be further combined to produce valuable bio-based chemicals, such as methyl methacrylate.…”