C-O Bond Hydrogenolysis of Aqueous Mixtures of Sugar Polyols and Sugars over ReOx-Rh/ZrO2 Catalyst: Application to an Hemicelluloses Extracted Liquor

Abstract

The recovery and upgrade of hemicelluloses, a family of heteropolysaccharides in wood, is a key step to making lignocellulosic biomass conversion a cost-effective sustainable process in biorefinery. The comparative selective catalytic C-O bond hydrogenolysis of C5-C6 polyols, sugars, and their mixtures for the production of valuable C6 and C5 deoxygenated products was studied at 200 °C under 80 bar H2 over ReOx-Rh/ZrO2 catalysts. The sugars were rapidly converted to the polyols or converted into their hydrogenolysis products. Regardless of the reactants, C-O bond cleavage occurred significantly via multiple consecutive deoxygenation steps and led to the formation of linear deoxygenated C6 or C5 polyols. The distribution of products depended on the nature of the substrate and C-C bond scission was more important from monosaccharides. In addition, we demonstrated effective hydrogenolysis of a hemicellulose-extracted liquor from delignified maritime pine containing monosaccharides and low MW oligomers. Compared with the sugar-derived polyols, the mono- and oligosaccharides in the liquor were more rapidly converted to hexanediols or pentanediols. C-O bond scission was significant, giving a yield of desired deoxygenated products as high as 65%, higher than in the reaction of the synthetic mixture of glucose/xylose of the same C6/C5 sugar ratio (yield of 30%).

Ru on N‐doped Carbon for the Selective Hydrogenolysis of Sugars and Sugar Alcohols

“…To enhance selectivity, many monometallic catalysts based on Cu, Ni, Pt or Ru were developed and tested in combination with a homogeneous base [8–14] . Additionally, recent research focused on the development of bimetallic catalysts to facilitate reactions with the addition of a solid base, without external hydrogen pressure or to further enhance selectivity [15–24] …”

“…[8][9][10][11][12][13][14] Additionally, recent research focused on the development of bimetallic catalysts to facilitate reactions with the addition of a solid base, without external hydrogen pressure or to further enhance selectivity. [15][16][17][18][19][20][21][22][23][24] Nevertheless, selectivity and activity control remains a major challenge. [25] In particular, ruthenium catalyzes side-reactions which lead to the formation of C 1 -products.…”

Kinetic Modeling for the “One-Pot” Hydrogenolysis of Cellulose to Glycols over Ru@Fe3O4/Polymer Catalyst

“…Glycols are the most important raw materials for many branches of modern industry. Ethylene glycol (EG) and propylene glycol (PG) are used in large volumes for the production of medicinal substances, surfactants, antifreeze, lubricants, solvents, fuels, and synthesis of polyester fibers and resins [4,5]. The question of how to effectively catalyze the conversion of cellulose into desired products is an interesting subject for many researchers.…”

Kinetics of Glucose Hydrogenolysis in the Presence of a Magnetically Recoverable Polymeric Catalyst

“…Гликоли -важнейшее сырье для многих отраслей современной промышленности. Этиленгликоль (ЭГ) и пропиленгликоль (ПГ) в больших объемах используются для производства лекарственных веществ, ПАВ, антифризов, смазок, растворителей, топлива, синтеза полиэфирных волокон и смол [4,5]. ЭГ и ПГ могут быть получены в условиях одного реактора гидрогенолизом целлюлозы в присутствии гетерогенных катализаторов [6,7].…”