DFT Study of Furfural Conversion to Furan, Furfuryl Alcohol, and 2-Methylfuran on Pd(111)

Dispersion-corrected density functional theory calculations were performed to investigate the adsorption of furan, furfural, furfuryl alcohol, and 2-methylfuran as well as the reaction barriers for their interconversion. The most stable configuration for furan, furfural, furfuryl alcohol, and 2-methylfuran entails the furan ring lying flat on the surface, centered over a hollow site. We performed an elementary step analysis for the reaction of furfural to furan, furfuryl alcohol, and 2-methylfuran. Thermodynamics favors the production of furan and CO. The activation energy for furfural reduction to furfuryl alcohol is lower than that for its decarbonylation to furan. The formation of 2-methylfuran occurs via dehydration of furfuryl alcohol or a dehydrogenation pathway through a methoxy intermediate. Our findings are in agreement with recently reported experimental results.