No abstract

The selective production of 1,3-propanediol from glycerol under mild reaction conditions is of high interest. The current work describes the use of a highly selective catalyst consisting of platinum supported on mordenite zeolite employed for the first time for vapor phase hydrogenolysis of glycerol to 1,3-propanediol under atmospheric pressure. The catalysts with varying Pt content (0.5−3 wt %) were prepared and thoroughly characterized by X-ray diffraction, temperature-programmed desorption of ammonia, FT-IR of adsorbed pyridine, CO chemisorptions, transmission electron microscopy, X-ray photoelectron spectroscopy, and BET surface area. The influence of reaction parameters has been studied to unveil the optimized reaction conditions. A high 1,3-propanediol selectivity (48.6%) was obtained over a 2 wt % Pt/H−mordenite catalyst at 94.9% glycerol conversion. According to the results obtained, the selectivity to 1,3-propanediol is better influenced by Pt dispersion and Brønsted acidity of the support. A plausible reaction mechanism has been presented. The spent catalyst exhibited consistent activity and selectivity toward the desired product during the glycerol hydrogenolysis reaction.

The hydrogenolysis of glycerol to 1,3-propanediol was conducted over a series of Pt-WO 3 /SBA-15 catalysts with Pt content ranging from 0.5 to 3 wt % and W content of 10 wt % in vapor phase under atmospheric pressure for the first time. The catalysts prepared via sequential impregnation method were systematically characterized using XRD, NH 3 -TPD, Py-IR, CO chemisorption, TPR, TEM, and surface area measurements. The catalysts exhibited unprecedented activity for selective formation of 1,3-propanediol via hydrogenolysis of glycerol. The effect of various reaction parameters such as catalyst loading, reaction temperature, hydrogen flow rate, glycerol concentration and reaction time were studied. The optimized reaction conditions showed that a high glycerol conversion (86%) and 1,3-propanediol selectivity (42%) was obtained over 2Pt-10WO 3 / SBA-15 catalyst illustrating the potential of SBA-15 supported platinum−tungsten catalyst to be highly active and efficient. The Brønsted acid sites of the catalyst formed due to addition of WO 3 enhanced selective formation of 1,3-propanediol.

No abstract

Biomass derived glycerol is considered an ideal feedstock with a prospective to be converted into a number of valuable compounds. Catalytic glycerol hydrogenolysis to produce 1,3-propanediol is one of the pioneering biosustainable pathways. Bimetallic Pt−Cu catalysts supported on H-mordenite were synthesized with various copper loadings and applied in the selective glycerol hyrogenolysis to 1,3-propanediol in a continuous fixed bed reactor performed in vapor phase under atmospheric pressure. Several techniques such as XRD, ICP-AES, NH 3 -TPD, Pyr FTIR, BET, TPR, HR-TEM, XPS, and solid state NMR were employed to characterize the physical and chemical properties of Pt−Cu/Mor catalysts. A detailed reaction parametric study has been carried out. The results designated that well dispersed Pt−Cu catalysts with small particle size, supported on a Brønsted acidic H-mordenite with a multiple pore system and strong bimetallic phase-support interaction, promote the selectivity to 1,3-propanediol. Over the Pt−Cu/Mor catalyst of optimum composition (2% Pt and 5% Cu by weight) and under the optimum reaction conditions (210 °C, H 2 flow rate of 80 mL min −1 , and gly concentration of 10 wt %), the glycerol conversion and 1,3-PD selectivity reached 90% and 58.5%, respectively. Structural characterizations and reusability of the Pt-5Cu/Mor catalyst were also performed. With evident advantages of selective C−O hydrogenolysis with low C−C cleavages, the bimetallic Pt−Cu/Mor catalysts hold great potential as high-performance catalysts for glycerol conversion to 1,3propanediol.

No abstract

No abstract

Nanostructured PdO/CeO supported on mesoporous SBA-15 silica was synthesized using a combination of incipient wetness impregnation and surface-assisted reduction. After calcination, the materials showed good activity as catalysts for the low-temperature oxidation of methane, with a sample having 5 wt % Pd loading showing 50% conversion to CO at ∼290 °C and complete conversion below 360 °C. The stability of catalysts in the presence of water was studied. The formation of Pd(0) during the methane oxidation reaction increases the oxygen vacancies on the surface of catalysts, improving the catalytic activity.