The H2 Pressure Dependence of Hydrodeoxygenation Selectivities for Furfural over Pt/C Catalysts

Hydrodeoxygenation of furfural was studied over a 10-wt% Pt/C catalyst at 453 K, under both low- and high-pressure conditions. With vapor-phase furfural as the feed and H-2 pressures below 1 bar, decarbonylation to furan is a major product, with the selectivity to furfuryl alcohol and dimethylfuran increasing with increasing H-2 pressure. When the reaction is performed at 33 bar, using 1-wt % furfural in 1-propanol solvent and high-pressure H-2, no evidence for decarbonylation was observed. At high pressures, the reaction is sequential, with all the furfural proceeding to methylfuran, which in turn reacts to over-hydrogenated products, including 2-methyltetrahydrofuran and 2-pentanone. It is suggested that the hydrogen surface coverage is responsible for the apparent differences in the reaction network at high and low pressures.