Microkinetic Modeling of Furan Hydrodeoxygenation over Transition-Metal Surfaces

Hydrodeoxygenation (HDO) of biomass-derived oxygenates present in bio-oil is a critical step in their conversion to high-value chemicals and fuels. Furanics represent a significant fraction of the bio-oil and are considered as potential platform chemicals to yield a variety of valuable chemicals. In this study, density functional theory calculations and a descriptor-based microkinetic modeling (MKM) approach were utilized to investigate furan HDO on transition-metal surfaces and predict activity and selectivity for the formation of ring-hydrogenated product like dihydrofuran (DHF), open-chain alcohols, aldehydes, and deoxygenated molecules as a function of carbon (EC) and oxygen-binding energies (EO). Deoxygenated products were favored at high temperatures and low pressures on surfaces with weak ECand strong EO, while alcohols were favored on surfaces with weak EOand low temperatures. DHF and aldehyde formation were favored at high H2pressures and low temperatures on surfaces having very weak oxygen-binding energies and very high carbon/oxygen-binding energies, respectively. Ni had high activity and selectivity toward deoxygenated products in agreement with experimental observations, while Pd and Pt show the highest activity and selectivity toward ring-hydrogenated products. Our MKM analysis was extended to screen single-atom alloy surfaces for HDO activity, and NiFe was found to be a potential deoxygenating catalyst in agreement with previous experimental studies.