Pd/Nb2O5/SiO2 Catalyst for the Direct Hydrodeoxygenation of Biomass-Related Compounds to Liquid Alkanes under Mild Conditions

• Published in: ChemSusChem Vol. 8; no. 10; pp. 1761 - 1767
• Main Authors: Shao, Yi, Xia, Qineng, Liu, Xiaohui, Lu, Guanzhong, Wang, Yanqin
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 22-05-2015; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: alkanes; Alkanes - chemistry; Biomass; Butanones - chemistry; Catalysis; heterogeneous catalysis; hydrodeoxygenation; niobium; Niobium - chemistry; Oxides - chemistry; Palladium - chemistry; Palmitic Acid - chemistry; Phenyl Ethers - chemistry; Silicon Dioxide - chemistry; Triglycerides - chemistry; hydrodeoxygenation; alkanes; biomass; heterogeneous catalysis; niobium
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.201500053

A simple Pd‐loaded Nb2O5/SiO2 catalyst was prepared for the hydrodeoxygenation of biomass‐related compounds to alkanes under mild conditions. Niobium oxide dispersed in silica (Nb2O5/SiO2) as the support was prepared by the sol–gel method and characterized by various techniques, including N2 adsorption, XRD, NH3 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 Nb2O5, Nb2O5/SiO2 has significantly more active niobium oxide species exposed on the surface. Under mild conditions (170 °C, 2.5 MPa), Pd/10 %Nb2O5/SiO2 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 NbOx 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.
Mild mannered: Under mild conditions (170 °C, 2.5 MPa), Pd/10 %Nb2O5/SiO2 is effective for the hydrodeoxygenation reactions of 4‐(2‐furyl)‐3‐buten‐2‐one (the aldol adduct of furfural with acetone), palmitic acid, tristearin, and diphenyl ether (model compounds of vegetable oils, microalgae oils, and lignin) and gives high yields (>94 %) of alkanes with little CC bond cleavage.