17108-52-0Relevant articles and documents
Poisoning of Ru/C by homogeneous Br?nsted acids in hydrodeoxygenation of 2,5-dimethylfuran via catalytic transfer hydrogenation
Gilkey, Matthew J.,Vlachos, Dionisios G.,Xu, Bingjun
, p. 327 - 335 (2017/06/19)
It has been proposed that the combination of metal and acid sites is critical for effective ring opening of biomass-derived furans to linear molecules, a reaction that holds promise for the production of renewable polymer precursors and alkanes. In this work, we use 2,5-dimethylfuran (DMF) as a model compound to investigate hydrogenolysis and hydrogenation pathways using a combination of H2SO4 and Ru-mediated catalytic transfer hydrogenation in 2-propanol. Acid-catalyzed hydrolytic ring opening of DMF to 2,5-hexanedione (HDN) occurs readily at 80?°C with a selectivity of 89% in 2-propanol. Over Ru/C, HDN is fully converted after only 2?h at 80?°C, forming a mixture of both ring-closed products (～68% total yield), i.e., 2,5-dimethyltetrahydrofuran (DMTHF) and 2,5-dimethyl-2,3-dihydrofuran (DMDHF), as well as ring opened products (～28% total yield), i.e., 2,5-hexanediol (2,5-HDL) and 2-hexanol (HOL). Rather than observing sequential hydrolysis/hydrogenation reactions, we observe severe suppression of metal chemistry when having both Ru/C and H2SO4 in the reaction system. While minor leaching of Ru occurs in the presence of mineral acids, X-ray photoelectron spectroscopy coupled with CO chemisorption studies suggest that the primary cause of the lack of Ru-mediated chemistry is poisoning by strongly adsorbed sulfate species. This hypothesis is supported by the observation of Ru-catalyzed chemistry when replacing H2SO4 with Nafion, a solid Br?nsted acid, as sulfonic acid groups tethered to the polymer backbone cannot adsorb on the metal sites.
Pd/C-catalyzed reactions of HMF: Decarbonylation, hydrogenation, and hydrogenolysis
Mitra, Joyee,Zhou, Xiaoyuan,Rauchfuss, Thomas
supporting information, p. 307 - 313 (2018/04/16)
The diverse reactivity of 5-hydroxymethylfural (HMF) in Pd/C-catalyzed reactions is described with emphasis on the role of additives that affect selectivity. Three broad reactions are examined: decarbonylation, hydrogenation, and hydrogenolysis. Especially striking are the multiple roles of formic acid in hydrogenolysis/hydrogenation and in suppressing decarbonylation, as illustrated by the conversion of HMF to DMF. Hydrogenation of the furan ring is suppressed by CO2 and carboxylic acids. These results emphasize the utility of Pd/C as a convenient catalyst for upgradation of cellulosic biomass.
