Gas‐Phase Hydrogenolysis of Glycerol Catalyzed by Cu/MO_x Catalysts

Abstract

The catalytic activities of Cu/MO x (MO x = Al 2 O 3 , TiO 2 , and ZnO) catalysts in the gas-phase hydrogenolysis of glycerol were studied at 180-300°C under 0.1 MPa of H 2 . Cu/MO x (MO x = Al 2 O 3 , TiO 2 , and ZnO) catalysts were prepared by the incipient wetness impregnation method. After reduction, CuO species were converted to metallic copper (Cu 0 ). Cu/Al 2 O 3 catalysts with high acidity, high specific surface areas and small metallic copper size favored the formation of 1,2-propanediol with a maximum selectivity of 87.9 % at complete conversion of glycerol and a low reaction temperature of 180°C, and favored the formation of ethylene glycol and monohydric alcohols at high reaction temperature of 300°C. Cu/TiO 2 and Cu/ZnO catalysts exhibited high catalytic activity toward the formation of hydroxyacetone with a selectivity of approx. 90 % in a wide range of reaction temperature.

Hydrodeoxygenation of Vicinal OH Groups over Heterogeneous Rhenium Catalyst Promoted by Palladium and Ceria Support

“…For substrates with a few OH groups, a number of partial hydrodeoxygenation systems that selectively remove one OH group have been reported such as glycerol to 1,2-propanediol, [2][3][4][5][6][7] glycerol to 1,3-propanediol, [8][9][10][11] 1,2-alkanediol to 1-alcohol, [8,11,12] and 1,2-cycloalkanediol to 1-cycloalkanol. [13] However, it is much more difficult to selectively remove OH groups with these catalysts from substrates with four or more OH groups such as erythritol, xylitol, and sorbitol.…”

Selective Hydrodeoxygenation of Cyclic Vicinal Diols to Cyclic Alcohols over Tungsten Oxide–Palladium Catalysts

“…These results indicate that high activity and selectivity to 3-HTHF originates from synergy between the WO 3 and Pd species. Given that WO 3 These results suggest that WO x is the active species and that the activity is promoted by the addition of Pd. The time courses of the 1,4-AHERY hydrodeoxygenation over WO x -Pd/ZrO 2 and WO x -Pd/C are shown in Figures 1 and 2, respectively.…”

“…The highest activity of WO x -Pd/C can be explained by the largest surface area of C in the tested supports except for SiO 2 . The lower activity of the SiO 2 -supported catalyst relative to that of the C-supported catalyst is probably due to the formation of inactive bulk WO 3 .…”

“…Removal of the hydroxyl groups from polyols is one class of hydrodeoxygenation. For straight-chain substrates, a number of systems with good selectivity have been reported, such as glycerol into 1,2-propanediol, [2][3][4][5] glycerol into 1,3-propanediol, [6][7][8][9] and 1,2-alkanediols into 1-alcohols. [6,9,10] However, removal of the hydroxyl groups on a cyclic structure is much more difficult, although they are frequently observed structures in biomass-related molecules such as sugars.…”

Selectively catalytic oxidation of 1,2-propanediol to lactic, formic, and acetic acids over Ag nanoparticles under mild reaction conditions

“…1,2-Propanediol derived from biomass-based polyols including glycerol and sorbitol via hydrogenolysis [17][18][19][20][21] has been now considered as an alternative and renewable carbon source for the synthesis of many highly value-added chemicals, such as lactic acid [22][23][24][25][26][27][28][29], pyruvic acid [30], acetic acid [22][23][24][25][27][28][29], formic acid [22][23][24][25][27][28][29], hydroxyacetone [24], propionic acid [31], and propanol [31], via either catalytic oxidation or bioconversion processes. However, 1,2-propanediol is facing the oversupply problem, especially in China, due to its limited demand in the production of organic solvent and unsaturated polyester resin [32,33] and the scaling-up coproduction of dimethyl carbonate and 1,2-propanediol by transesterification method [34].…”