Catalytic Hydrodeoxygenation of High Carbon Furylmethanes to Renewable Jet‐fuel Ranged Alkanes over a Rhenium‐Modified Iridium Catalyst

• Published in: ChemSusChem Vol. 10; no. 16; pp. 3225 - 3234
• Main Authors: Liu, Sibao, Dutta, Saikat, Zheng, Weiqing, Gould, Nicholas S., Cheng, Ziwei, Xu, Bingjun, Saha, Basudeb, Vlachos, Dionisios G.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 24.08.2017; ChemPubSoc Europe
• Subjects: Alkanes; Cascade chemical reactions; Catalysis; catalysis (homogeneous), catalysis (heterogeneous), biofuels (including algae and biomass), bio-inspired, hydrogen and fuel cells, materials and chemistry by design, synthesis (novel materials), synthesis (self-assembly), synthesis (scalable processing); Catalysts; Chemical synthesis; Furans; Furans - chemistry; hydrodeoxygenation; Hydrogen - chemistry; Hydrogenation; Hydrogenolysis; Iridium; Iridium - chemistry; Lignocellulose; Methane - chemistry; Oxygen - chemistry; Pressure; reaction mechanisms; Rhenium; Rhenium - chemistry; Ring opening; Silicon dioxide; Silicon Dioxide - chemistry; Temperature; iridium; hydrodeoxygenation; reaction mechanisms; alkanes; rhenium
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.201700863

Renewable jet‐fuel‐range alkanes are synthesized by hydrodeoxygenation of lignocellulose‐derived high‐carbon furylmethanes over ReOx‐modified Ir/SiO2 catalysts under mild reaction conditions. Ir−ReOx/SiO2 with a Re/Ir molar ratio of 2:1 exhibits the best performance, achieving a combined alkanes yield of 82–99 % from C12–C15 furylmethanes. The catalyst can be regenerated in three consecutive cycles with only about 12 % loss in the combined alkanes yield. Mechanistically, the furan moieties of furylmethanes undergo simultaneous ring saturation and ring opening to form a mixture of complex oxygenates consisting of saturated furan rings, mono‐keto groups, and mono‐hydroxy groups. Then, these oxygenates undergo a cascade of hydrogenolysis reactions to alkanes. The high activity of Ir−ReOx/SiO2 arises from a synergy between Ir and ReOx, whereby the acidic sites of partially reduced ReOx activate the C−O bonds of the saturated furans and alcoholic groups while the Ir sites are responsible for hydrogenation with H2. The difference is plane: Renewable jet‐fuel‐range alkanes are synthesized in 82–99 % yield by hydrodeoxygenation of lignocellulose‐derived furylmethanes over Ir−ReOx/SiO2 catalysts under mild reaction conditions. The high catalyst activity arises from synergy between Ir and ReOx, whereby the acidic sites of partially reduced ReOx activate the C−O bonds of the saturated furans and alcoholic groups, while the Ir sites are responsible for hydrogenation.