The high oxygen content (35-40 %) of bio-oil produced from fast pyrolysis of biomass reduces the heating value and stability, and limits its subsequent use as a transportation fuel. Catalytic hydrodeoxygenation (HDO) is a promising emerging technology that can be used to lower the oxygen content, but suitable catalysts need to be developed. In order to better understand the HDO chemistry we compare it to the well-studied hydrodesulfurization process (HDS) used in the petroleum refining industry for the removal of sulfur.We studied furan-HDO (analogous to thiophene-HDS) on the RuO2(110) and MoO3(010) surfaces, which are the oxide analogues of the most active RuS2 and the industrially used MoS2 catalysts for HDS. A prominent density functional theory (DFT) study of thiophene-HDS on MoS2 is used as a reference [1]. Similar to HDS, HDO requires the initial creation of an oxygen-vacancy site on the surface under high hydrogen pressures where the feed molecule is adsorbed. The potential energy diagram based on the thermodynamic stability of reaction intermediates suggests that the reaction pathways for HDS of thiophene and HDO of furan are similar. Activation barriers for elementary surface reactions further indicate that furan-HDO on RuO2 and MoO3 is facile. Vacancy formation energies have been used as a descriptor to predict HDS trends in metal-sulfides and our results indicate that this descriptor is also suitable for HDO on metal-oxides. Transition metal doping may be used to further improve their overall catalytic properties. Unraveling the similarities and differences between the two processes and identifying a reactivity descriptor for HDO on oxides will ultimately let us design a novel HDO catalyst for the commercialization of bio-fuels and chemicals.References[1] Poul Georg Moses, Berit Hinnemann, Henrik Tops�e, Jens K. N�rskov, Journal of Catalysis, 248  (2007) 188-203.

Hydrodeoxygenation of furan vs. hydrodesulfurization of thiophene: A first principles investigation

247th National Meeting (2014)

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