Ketone Formation via Decarboxylation Reactions of Fatty Acids Using Solid Hydroxide/Oxide Catalysts

Benjamin Smith,Diego Perera-Solis,Philip Dyer,Vladimir Zholobenko,Louise Gildea,H Greenwell,Li Li

doi:10.3390/inorganics6040121

Benjamin Smith, Diego Perera-Solis + Show 5 more

Open Access

https://doi.org/10.3390/inorganics6040121

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Journal: Inorganics	Publication Date: Nov 8, 2018
Citations: 7	License type: CC BY 4.0

Affiliation: Durham University, Keele University

Abstract

A sustainable route to ketones is described where stearone is produced via ketonic decarboxylation of stearic acid mediated by solid base catalysts in yields of up to 97%, at 250 °C. A range of Mg/Al layered double hydroxide (LDH) and mixed metal oxide (MMO) solid base catalysts were prepared with Mg/Al ratios of between 2 and 6 via two synthetic routes, co-precipitation and co-hydration, with each material tested for their catalytic performance. For a given Mg/Al ratio, the LDH and MMO materials showed similar reactivity, with no correlation to the method of preparation. The presence of co-produced oxide phases in the co-hydration catalysts had negligible impact on reactivity.

Highlights

Crude oil is a finite feedstock and attempts are being made to extend the shelf life of infrastructure and chemical processes that rely on its use by producing sustainable bio-derived fuels and chemicals [1,2]
Often when comparing catalytic reactions mediated by layered double hydroxide (LDH)/mixed metal oxide (MMO) it can be difficult to separate the effect of differing variables between studies
It was found that the validation curves showed higher significance for stearone than for stearic acid, and so these were used for reaction conversion values. Independent of their composition (R-values = 1–6) and method of preparation, cheap, non-toxic, Al/Mg LDHs and MMOs all mediate the ketonic decarboxylation of stearic acid to stearone at moderate temperatures (250 ◦ C) with excellent conversion (~90%)

Summary

Introduction

Crude oil is a finite feedstock and attempts are being made to extend the shelf life of infrastructure and chemical processes that rely on its use by producing sustainable bio-derived fuels and chemicals [1,2]. Certain seeds, plants, and algae can be processed to afford oils, where the majority of the non-polar oil components are in the form of triacyl glycerides (TAGs), consisting of an ester of glycerol bearing three saturated or unsaturated fatty acid residues [3]. These TAGs can be readily hydrolysed to form glycerol, itself a potential source of fuels and chemicals, and free fatty acids (FFA) [4]. A solid ceria catalyst was used to convert acetic acid (used as a model FFA) to acetone [9]

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