Pd/Nb2O5/SiO2Catalyst for the Direct Hydrodeoxygenation of Biomass-Related Compounds to Liquid Alkanes under Mild Conditions

Abstract A simple Pd‐loaded Nb 2 O 5 /SiO 2 catalyst was prepared for the hydrodeoxygenation of biomass‐related compounds to alkanes under mild conditions. Niobium oxide dispersed in silica (Nb 2 O 5 /SiO 2 ) as the support was prepared by the sol–gel method and characterized by various techniques, including N 2 adsorption, XRD, NH 3 temperature‐programmed desorption (TPD), TEM, and energy‐dispersive X‐ray spectroscopy (EDAX) atomic mapping. The characterization results showed that the niobium oxide species were amorphous and well dispersed in silica. Compared to commercial Nb 2 O 5 , Nb 2 O 5 /SiO 2 has significantly more active niobium oxide species exposed on the surface. Under mild conditions (170 °C, 2.5 MPa), Pd/10 %Nb 2 O 5 /SiO 2 was effective for the hydrodeoxygenation reactions of 4‐(2‐furyl)‐3‐buten‐2‐one (aldol adduct of furfural with acetone), palmitic acid, tristearin, and diphenyl ether (model compounds of microalgae oils, vegetable oils, and lignin), which gave high yields (>94 %) of alkanes with little CC bond cleavage. More importantly, owing to the significant promotion effect of NbO x species on CO bond cleavage and the mild reaction conditions, the CC cleavage was considerably restrained, and the catalyst showed an excellent activity and stability for the hydrodeoxygenation of palmitic acid with almost no decrease in hexadecane yield (94–95 %) in a 150 h time‐on‐stream test.