(166d) Gas Phase Hydrodeoxygenation (HDO) of Fufural On Molybdenum Carbide Catalysts

The underlying challenge in converting biomass feedstock with a (CH₂O)_n stoichiometry to fuels with (CH₂)_n stoichiometry is the selective removal of oxygen without a concurrent decrease in the carbon chain length.  For hydrodeoxygenation (HDO) reactions in which H₂ is usually in excess, it is important to utilize the H₂ for oxygen removal rather than unwanted hydrogenation reactions of C=C double bonds to avoid extra hydrogen consumption.  In this work, we report the gas phase HDO of furfural over bulk Mo₂C in excess of hydrogen (H₂/furfural molar ratio ~390) at low temperatures (~150 °C) to selectively accomplish C=O scission to form 2-methylfuran with 60-65% selectivity; and the selectivity for the C-C bond scission product, furan, was less than 1%.  The hydrogenation product of 2-methylfuran (2-methyltetrahydrofuran) is formed in negligible quantities suggesting that HDO is the dominant reaction pathway.  Detailed kinetics studies including apparent activation energy and reaction orders, isotopic experiments, and in-situ titration studies were performed to elucidate the reaction mechanism and sites requirements for furfural HDO reactions and will be reported in this presentation.