Low-cost cobalt catalyst effective for conversion of sorbitol to monofunctional fuel precursors

September 6, 2017May 15, 2020 Nathaniel Eagan

Abstract:
Hydrodeoxygenation of sugar alcohols can be tuned to produce monofunctional oxygenates for use as jet or diesel fuel precursors. However, the catalysts typically utilize precious metals and are not highly selective. Here, the hydrodeoxygenation of aqueous sorbitol was studied over a Co/TiO2 catalyst to produce monofunctionals at a 56 C% yield. The majority of these species are alcohols (69%) or heterocycles (23%) while ketones and aldehydes are readily hydrogenated. 67% of the monofunctionals are C5-C6. Fourier transform ion cyclotron resonance mass spectrometry provided evidence for the coupling of C3 and C6 oxygenates to C9+ oligomeric species, which likely fragment and deoxygenate to form C1-C6 monofunctionals and gases. Co/TiO2 deactivation occurred irreversibly due to sintering and leaching promoted by oxygenated species. Our results suggest that low-cost base metal catalysts can be as effective as many precious metal catalysts for monofunctional production from sorbitol toward heavy fuels if catalyst deactivation issues can be overcome.