Hydrogenation of furfural at the dynamic Cu surface of CuOCeO2/Al2O3 in vapor phase packed bed reactor

Authors: Jackson, Michael - Mike; WHITE, MARK - Mississippi State University; HAASCH, ROCHARD - University Of Illinois; Peterson, Steven - Steve; Blackburn, Judith

Submitted to: Journal of Molecular Catalysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/17/2017
Publication Date: 11/23/2017
Citation: Jackson, M.A., White, M.G., Haasch, R.T., Peterson, S.C., Blackburn, J.A. 2017. Hydrogenation of furfural at the dynamic Cu surface of CuOCeO2/Al2O3 in vapor phase packed bed reactor. Journal of Molecular Catalysis. 445:124-132. doi: 10.1016/j.mcat.2017.11.023.
DOI: https://doi.org/10.1016/j.mcat.2017.11.023

Interpretive Summary: This work was undertaken to increase the value of crop residues by expanding the number of products and improving the efficiencies at which they can be produced at a biorefinery. Biorefineries can utilize crop residues in a supply chain that isolates the sugar xylose which in turn is converted to furfural. This compound is then treated with hydrogen to give the marketable product furfuryl alcohol. This reaction requires a catalyst and it is the performance of the catalyst that determines if the reaction is commercially viable. The catalyst we developed is comparable in performance to that currently used in industry but works without toxic chromium in its make-up. Continued development of catalytic conversions of biomass will aid in the expansion of biorefineries which contribute to rural economic opportunities.

Technical Abstract: The hydrogenation of furfural to furfuryl alcohol over a CuOCeO2/'-Al2O3 catalyst in a flow reactor is reported. The catalyst was prepared by the wet impregnation of Cu onto a CeO2/'-Al2O3 precursor. The calcined catalyst was then treated with HNO3 to remove surface CuO resulting in a mixed CuCe oxide supported on '-Al2O3. The catalyst was characterized by BET surface measurements, powder XRD, EDX, XPS, and H2-TPR. Reduction of the catalyst results in migration of Cu2O to the surface of the solid solution. The CeO2 facilitates the reduction of the Cu which in turn leads to increased activated hydrogen being available at the reaction temperature. Furfural hydrogenation was carried out in a downflow reactor at 175'C under hydrogen pressures ranging from 1 to 10 bar. Selectivity to furfuryl alcohol and time on stream before loss of activity due to coke formation were greater at higher pressure. Coke formation was greater at higher furfural flow rates indicating a competition exists between hydrogenation and coke formation. The side products that were measured included 2-methylfuran and difurfuryl ether. The kinetics of the reduction of the Cu sites are also described and found to contribute to catalyst activity. Comparison to commercial copper chromite and 5 wt% Cu/Al2O3 were made to assess practical application of this catalyst.