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Efficient utilization of renewable biomass plays a vital role in CO2 mitigation. Direct conversion of cellulose, the most abundant fraction in lignocellulosic biomass, into ethylene glycol is a promising route. In this work, by using the biowaste pomelo peel as the carbon precursor, the Ru–WOX/biochar (BC) bifunctional catalyst was prepared via pyrolysis in a nitrogen atmosphere without further reduction. Cellulose could be efficiently converted into ethylene glycol with a yield of 68.8% after 10 h using Ru–WOX/BC at the temperature of 220 °C and 3 MPa H2. The effects of reaction temperature, reaction time, H2 pressure and catalysts obtained from different pyrolysis temperatures on the yield of ethylene glycol were investigated. The characterization and reaction results showed that the gas generated from pyrolysis of pomelo peel could partially reduce ruthenium precursor to metallic form. Metallic Ru can not only promote the reduction of W6+ to W5+, but also work on hydrogenation reaction. The catalyst and preparation method have a promising application in cellulose conversion. [ABSTRACT FROM AUTHOR]

Sorbitol, as a C6 sugar related compound derived from cellulose, is regarded as a promising biomass‐derived substrate and has characteristically higher oxygen content than in fossil‐based resources. In this work, ruthenium–molybdenum carbon catalysts prepared by different impregnation processes were employed and extensively studied in a trickle‐bed reactor for sorbitol hydrodeoxygenation (HDO). Interestingly, these catalysts afforded remarkably different HDO performance. Ruthenium–molybdenum catalysts prepared by ultrasonic treatment and calcination obtained high HDO performance in sorbitol conversion with 79.8 % carbon yield of C5/C6 alkanes (pentane and hexane), almost twice that of ruthenium–molybdenum catalysts prepared without using a calcination processes. Therefore, a series of characterization studies (N2‐adsorption, XRD, HRTEM, XPS, H2‐TPR, CO‐TPD, NH3‐TPD, Py‐IR spectra, etc.) were performed over relevant catalysts to study the catalytic mechanism. The results suggest that prior calcination offers a better chance for the proximity between Ru and Mo precursors to produce the bimetallic catalytic structure Ru–MoOx, which produces high HDO performance. Sweet catalysis: Ru–MoOx/C catalysts from different impregnation processes were carefully studied and extensively employed for sorbitol conversion to C5/C6 alkanes in trickle‐bed reactor. The results suggest that prior calcination offers a better chance for the proximity between Ru and Mo precursors to produce the bimetallic catalytic structure Ru–MoOx, which produces high HDO performance towards biofuels synthesis. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract: For the aqueous-phase hydrodeoxygenation (APHDO) of carboxylic acids over the Ru/C, Ru/ZrO2 and Ru/Al2O3 catalysts, the Cnation and C–C bond cleavage reactions were studied by collecting reaction kinetics data and the measures of DRIFTS. The C–C bond cleavage was improved at high temperature and with high metal loadings. The acidic supports in combination with Ru metal can favor the Cnation of carboxyl. The C–C bond cleavage derived from the decarbonylation of acyl on the catalyst was studied by the measures of DRIFTS. The APHDO and DRIFTS results demonstrated that the C–C bond cleavage was favored in the order of Ru/C>Ru/ZrO2 >Ru/Al2O3. The catalysts were characterized by multiple methods (H2-TPR, NH3-TPD, CO-FTIR and DRIFTS of propanoic acid). It is concluded that the effect of support on the reaction routes may be attributed to these factors of catalysts, i.e., surface acidity, metal–support interaction and electronic state of Ru species. [Copyright &y& Elsevier]

The Cover shows the catalytic conversion of biomass hydrolysate into renewable alkanes over a Ru/C catalyst with aqueous phosphoric acid (Ru/C+H3PO4), in which a high yield of C5/C6 alkanes was obtained.In their Full Paper, Y. Weng et al. investigated the mechanism of the sorbitol hydrodeoxygenation (HDO) reaction into alkanes over a Ru/C+H3PO4 catalyst by using a trickle‐bed reactor. Higher HDO performance might be a result of the bifunctional role of the catalytic system. These findings suggest that the downstream process of biomass hydrolysis could be directly conducted in acid aqueous phase at low reaction temperature, reducing the amount of acid waste. [ABSTRACT FROM AUTHOR]