Hydrogenolysis of Glycerol to Propanediols Over Highly Active Ru–Re Bimetallic Catalysts

Abstract

Several supported Ru-Re bimetallic catalysts (Ru-Re/SiO 2 , Ru-Re/ZrO 2 , Ru-Re/TiO 2 , Ru-Re/H-b, Ru-Re/H-ZSM5) and Ru monometallic catalysts (Ru/SiO 2 , Ru/ZrO 2 , Ru/TiO 2 , Ru/H-b, Ru/H-ZSM5) were prepared and their catalytic performances were evaluated in the hydrogenolysis of glycerol to propanediols (1,2-propanediol and 1,3-propanediol) with a batch type reactor (autoclave) under the reaction conditions of 160°C, 8.0 MPa and 8 h. Compared with Ru monometallic catalysts, the Ru-Re bimetallic catalysts showed much higher activity in the hydrogenolysis of glycerol, and Re exhibited obvious promoting effect on the performance of the catalysts. The supported Ru monometallic catalysts and Ru-Re bimetallic catalysts were characterized by N 2 adsorption/desorption, XRD, TEM-EDX, H 2 -TPR and CO chemisorption for obtaining some physicochemical properties of the catalysts, such as specific surface areas, crystal phases, morphologies/microstructure, reduction behaviors and dispersion of Ru metal. The results of XRD and CO chemisorption indicate that the addition of Re component could improve the dispersion of Ru species on supports. The measurements of H 2 -TPR revealed that the coexistence of Re and Ru components on supports changed the respective reduction behavior of Re or Ru alone on the supports, indicating the existence of synergistic effect between Ru and Re species on the bimetallic catalysts. The hydrogenolysis of some products (such as 1,2-propanediol, 1,3-propanediol, 1-propanol and 2-propanol) were also examined over Ru and Ru-Re catalysts for evaluating influence of Re-Re on the reaction routes during glycerol hydrogenolysis. The results showed that over Ru-Re catalysts, glycerol was favorable to be converted to 1,2-propanediol, but not favorable to ethylene glycol, while 1,2-propanediol and 1,3-propanediol were favorable to be converted to 1-propanol. The influence of glycerol concentration in its aqueous solution on the catalytic performance was also evaluated over Ru and Ru-Re catalysts.

Hydrogenation of succinic acid to 1,4-butanediol over Re–Ru bimetallic catalysts supported on mesoporous carbon

“…The reduction peak of 0.45Re-0.15Ru/MC catalyst moved toward lower temperature and showed more narrow shape than that of 0.6Re/MC. In case of bimetallic catalysts containing noble metals such as Pd, Pt, and Ru, the noble metals can affect the reduction of the other metal due to hydrogen transfer from their reduced species [26][27][28][29]. Therefore, it can be inferred that hydrogen adsorbed on reduced ruthenium species was transferred to unreduced neighboring rhenium species during the reduction process, which promoted the reduction of rhenium species.…”

Influence of reduction time of copper based catalysts: Cu/Al2O3 and CuCr2O4 on hydrogenolysis of glycerol

“…1,3-propanediol is used for the production of poly(trimethylene terephthalate) known for its good resilience and dyeability6 -7 . 1,3-Propanediol can also be applied in the production of polyethers, polyurethanes 8 , polyesters, plasticizers, paints, copolymers 9 , laminates, resins, detergents and cosmetics 10 . Hydrogenolysis of glycerol proceeds by dehydration of glycerol to the intermediates: acetol and 3-hydroxypropanal and their subsequent hydrogenation to 1,2-and 1,3-propanediol respectively.…”

Navigating Glycerol Conversion Roadmap and Heterogeneous Catalyst Selection Aided by Density Functional Theory: A Review

“…Representative metal-based catalysts for glycerol hydrogenolysis are summarized in Table 2. 1 Conversion is defined in Reference [85]. 2 Conversion is achieved after 20 h of experiment.…”

“…Carbonium ions are believed to convert 12-PDO further into 1-PO under acidic conditions. Ma et al [85] added Re to Ru to promote glycerol conversion of glycerol and the selectivities of PDOs. In this case, Re is shown to prevent Ru particles from aggregation.…”