New insights into the mechanism of sorbitol transformation over an original bifunctional catalytic system.

Lea Vilcocq (1) , Amandine Cabiac (1) , Catherine Especel (2) , Sylvie Lacombe (1) , Daniel Duprez (2)

1 IFPEN - IFP Energies nouvelles
2 IC2MP [Poitiers] - Institut de chimie des milieux et matériaux de Poitiers [UMR 7285]

Sorbitol can be selectively transformed into liquid alkanes over a bifunctional catalytic system Pt/ZrO2 + TiO2–WOx. In this paper, we investigated the reaction mechanism by carefully analyzing the numerous products issued from sorbitol and by studying the reactivity of some identified intermediates (1-hexanol 2-hexanol, 2-hexanone, 2,5-dimethyltetrahydrofuran, 1,2-hexanediol and 1,2,6-hexanetriol). This led us to propose that C C cleavage reactions occur on terminal C C bonds and mainly consist of dehydrogenation-–decarbonylation reactions. The limiting steps of the sorbitol transformation are the isosorbide and mono-oxygenated intermediate transformations, especially the hydrogenation of ketones. It is also assessed that diols or triols with n carbon atoms are mainly converted in compounds with n − 1 carbon atoms. Short compounds (1 to 3 carbon atoms) are obtained via a dehydrogenation-retroaldol reaction pathway and not from isosorbide conversion.

Mots clés: Alkanes production; Biofuels; Biomass; Polyol; Pt; TiO2–WOx

Domaines: Chimie

Lea Vilcocq, Amandine Cabiac, Catherine Especel, Sylvie Lacombe, Daniel Duprez. New insights into the mechanism of sorbitol transformation over an original bifunctional catalytic system.. Journal of Catalysis, 2014, 320, pp.16-25. ⟨10.1016/j.jcat.2014.09.012⟩. ⟨hal-01138563⟩