Hydrogenation of 2,5-dimethylfuran on hexagonal-boron nitride- and silica-supported platinum catalysts

Hydrogenation of furanic compounds is one of the important reactions for upgrading of bio-oils and production of diesel fuels. Platinum catalysts supported on amorphous silica and hexagonal boron nitride (h-BN) were prepared by incipient wetness impregnation and subsequent reduction, and were used for the vapor-phase hydrogenation of 2,5-dimethylfuran in hydrogen at atmospheric pressure and a temperature range of 150–350 °C. For the same amount of Pt loading (1 wt%), the particle size of Pt supported on h-BN was larger than that on silica, resulting in a lower amount of CO chemisorption for Pt/BN than that for Pt/SiO₂. Using the same amount of active sites, Pt/BN exhibited a 3-fold higher turnover frequency than Pt/SiO₂ for the hydrogenation of 2,5-dimethylfuran whereas both catalysts gave similar product distributions with high selectivity to 2-hexanone at any conversion and low selectivity to n-hexane at high conversion. Contact time studies of 2,5-dimethylfuran hydrogenation on Pt/BN suggested that 2,5-dimethylfuran formed the ring-opening product, 2-hexanone and the ring-saturation product, 2,5-dimethyltetrahydrofuran in parallel, with the rate of the direct furan ring-opening being 9-fold higher than that of the furan ring-saturation.