Theoretical and experimental studies of the adsorption geometry and reaction pathways of furfural over FeNi bimetallic model surfaces and supported catalysts

Controlling the activity and selectivity of hydrodeoxygenation (HDO) of biomass-derivatives is critical for the utilization of biomass as renewable sources for chemicals and fuels. Furfural, produced by the hydrolysis and dehydration of xylose from hemicellulose, is a promising biomass-derivative to produce important biofuels like 2-methylfuran. Using a combination of density functional theory (DFT) calculations and surface science measurements on Fe/Ni(111) model surfaces, our results indicate that furfural bonds to the bimetallic surfaces primarily through the C=O bond with the furan ring tilted away from the surface, leading to the production of 2-methylfuran through the HDO reaction with furfuryl alcohol being identified as the likely intermediate. Similar preferential interaction of the C=O group over the furan ring is also confirmed on SiO2-supported FeNi bimetallic catalysts. The similar trends observed on model surfaces and supported catalysts demonstrate the feasibility of using single crystal surfaces to identify precious-metal-free bimetallic catalysts for biomass conversion. (C) 2014 Elsevier Inc. All rights reserved.