Yujing Weng

Aqueous‐Phase Hydrodeoxygenation of Biomass Sugar Alcohol into Renewable Alkanes over a Carbon‐Supported Ruthenium with Phosphoric Acid Catalytic System

Recently, we demonstrated the catalytic conversion of biomass hydrolysate and real biomass into renewable alkanes over a Ru/C catalyst with aqueous phosphoric acid (Ru/C+H3PO4) and we obtained a high yield of C5/C6 alkanes. In this study, the mechanism of sorbitol hydrodeoxygenation (HDO) into alkanes over the Ru/C+H3PO4 catalytic system was investigated by using a trickle‐bed reactor. A high HDO performance was detected with a large amount of long‐chain alkanes in the products. Subsequently, pre‐ and postcharacterization studies (N2 adsorption, XRD, X‐ray photoelectron spectroscopy, TEM, NH3 temperature‐programmed desorption, H2 temperature‐programmed reduction, FTIR spectroscopy) were performed on the relevant catalysts to study the change of the catalytic active sites. Moreover, mineral acid experiments were performed to study the influence of phosphoric acid on the HDO performance.

Promotion of Ni/MCM-41 Catalyst for Hydrogenation of Naphthalene by co-Impregnation with Polyols

The activities of nickel supported on MCM-41 catalysts, prepared by co-impregnation with polyols (ethylene glycol, glycerol, xylitol, sorbitol and glucose), were investigated by hydro- genation of naphthalene. Compared with the conventional wetness impregnation, addition of moderate polyols into the metal nitrate aqueous solution could enhance interaction with support surface, resulting in formation of very small NiO particle size (<5 nm), high dispersion of the active phase and significant catalytic activity. Particle size of Ni 0 decreased from 36.1 nm to below 5 nm; meanwhile the complete hydrogenation of naphthalene was dependent on the Ni 0 particle size. The hydrogenation activities of the catalysts prepared by co-impregnation with polyols were very high with 100% conversion even at low temperature of 55 °C.

Hydrodeoxygenation of Sorbitol into Bio-Alkanes and -Alcohols Over Phosphated Ruthenium Molybdenum Catalysts

Biofuels such as renewable alkanes and higher alcohols have drawn considerable interests for the use in internal combustion engines. Especially, higher alcohols could be used as a blending agent for diesel fuels. Herein, carbon supported phosphated ruthenium‐molybdenum (RuMoP) catalysts were employed in continuous trickle‐bed reactor for converting sorbitol into renewable alkanes and higher alcohols. The results showed that RuMoP on an active carbon (AC) support presented a complete sorbitol conversion and high yields of alkanes and alcohols in gasoline and diesel range. Subsequently, carbon nanotube (CNT) supported RuMoP was prepared and studied in detail for comparison. RuMoP/CNT presented a low C−C bond cracking property in sorbitol conversion and high selectivity of C6 products in gas‐phase (C6 alkane, 74.7u2009%) and oil‐phase (C6 alkane and alcohols, 87.8u2009%). Finally, detailed characterizations (N2‐adsorption, XRD, HRTEM, XPS, NH3‐TPD, Py‐IR spectrums, etc.) were performed over relevant catalysts (RuMoP/C and RuMoP/CNT) for correlating their catalytic and physicochemical properties.

Preparation of Highly Dispersed Co/SiO 2 Catalyst Using Ethylene Glycol and Its Application in Vapor-Phase Hydrogenolysis of Ethyl Lactate to 1,2-Propanediol

Highly dispersed Co catalysts supported on SiO2 were prepared in the presence of ethylene glycol (EG) by co-impregnation and tested in the vapor-phase hydrogenolysis of ethyl lactate to 1,2-propanediol. The synthesis parameters of Co metal loading, ratio of EG to cobalt nitrate, type of alcohol and calcination temperature, which influenced the physical properties of the Co3O4 nanoparticles, were investigated through the use of X-ray diffraction (XRD). It revealed that the ratio of EG to cobalt nitrate and the type of alcohol significantly affected the particle size of Co3O4 supported on SiO2. During co-impregnation with EG, the interaction between Co2+ and the SiO2 support was strongly enhanced, resulting in the high dispersion of cobalt species and the decrease of Co3O4 particle size from 16 nm to below 5 nm; the significantly enhanced cobalt dispersion was associated with the formation of amorphous cobalt silicate. Meanwhile the conversion of ethyl lactate was greatly improved to 98.6% from 69.5%, with 98.0% selectivity of 1,2-propanediol over 10% (w, mass fraction) Co/SiO2 catalysts under the given reaction conditions (2.5 MPa and 160 degrees C). The obtained catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N-2 adsorption-desorption measurements, and H-2 temperature-programmed reduction (H-2-TPR) methods.Highly dispersed Co catalysts supported on SiO2 were prepared in the presence of ethylene glycol (EG) by co-impregnation and tested in the vapor-phase hydrogenolysis of ethyl lactate to 1,2-propanediol. The synthesis parameters of Co metal loading, ratio of EG to cobalt nitrate, type of alcohol and calcination temperature, which influenced the physical properties of the Co3O4 nanoparticles, were investigated through the use of X-ray diffraction (XRD). It revealed that the ratio of EG to cobalt nitrate and the type of alcohol significantly affected the particle size of Co3O4 supported on SiO2. During co-impregnation with EG, the interaction between Co2+ and the SiO2 support was strongly enhanced, resulting in the high dispersion of cobalt species and the decrease of Co3O4 particle size from 16 nm to below 5 nm; the significantly enhanced cobalt dispersion was associated with the formation of amorphous cobalt silicate. Meanwhile the conversion of ethyl lactate was greatly improved to 98.6% from 69.5%, with 98.0% selectivity of 1,2-propanediol over 10% (w, mass fraction) Co/SiO2 catalysts under the given reaction conditions (2.5 MPa and 160 degrees C). The obtained catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N-2 adsorption-desorption measurements, and H-2 temperature-programmed reduction (H-2-TPR) methods.