02147nas a2200217 4500008004100000022001400041245016000055210006900215260000800284300001600292490000800308520134400316653001701660653002301677653001101700653002101711653002901732100002201761700002201783856012401805 2020 eng d a2468-823100aUnderstanding the influence of alumina supported ruthenium catalysts synthesis and reaction parameters on the hydrodeoxygenation of lignin derived monomers0 aUnderstanding the influence of alumina supported ruthenium catal cJAN aUNSP 1105250 v4803 a

Up-gradation of lignin derived monomers to value-added and fuel grade products is important to make overall bio-refinery process economical. Although, few studies are devoted on this work yet, systematic study on commercially viable (low loading of metal, recyclable catalyst, mild conditions, high selectivities etc.) is scarce and typically done under harsh conditions. Herein, we report, the methodical effect of support (SiO2, Al2O3 (acidic, basic and neutral), SiO2-Al2O3) on the hydrodeoxygenation (HDO) of lignin derived various monomers, guaiacol, veretrol, eugenol, phenol using very low loading (0.5 wt%) Ru catalyst. Very high yield (82%) of cyclohexanol from guaiacol could be achieved in presence of cyclohexane as a solvent and Ru/Al2O3-Acidic catalyst at 225 degrees C and under 1 MPa H-2 pressure. The detailed study on the effect of solvent, stability and adsorption of reactant & products etc. is done and it was observed that products are more prone to adsorb and undergo further reactions. The complete characterization of fresh and spent catalysts revealed that lower catalyst reduction temperature and presence of Ru in partially higher oxidation state proved by XPS, helps in enhancing the cyclohexanol formation. Subsequently, role of Ru particle size and support on the activity was also investigated.

10aCyclohexanol10aHydrodeoxygenation10alignin10areaction pathway10asupported metal catalyst1 aSingh, Dheerendra1 aDhepe, Paresh, L. uhttps://library.ncl.res.in/content/understanding-influence-alumina-supported-ruthenium-catalysts-synthesis-and-reaction01530nas a2200217 4500008004100000022001400041245014900055210006900204260000900273300001100282490000800293520071800301653004301019653001701062653002301079653001101102653003001113100002201143700002201165856012501187 2021 eng d a1566-736700aEfficient catalytic transfer hydrogenation-hydrodeoxygenation of lignin derived monomers: investigating catalyst properties-activity correlation0 aEfficient catalytic transfer hydrogenationhydrodeoxygenation of  cJAN  a1062200 v1493 a

Reduction of O/C ratio of lignin derived monomers via hydrodeoxygenation (HDO) pathway is conventionally furnished using molecular hydrogen under severe conditions. Nonetheless, due to a prerequisite to accomplish HDO through commercially attractive methodology we report, HDO reactions of various phenolic compounds via catalytic transfer hydrogenation (CTH) pathway using very low loading of Ru (0.5 wt%) on neutral and acidic Al2O3 under nitrogen atmosphere. With guaiacol as a substrate, 74% cyclohexanol yield at 225 degrees C in the presence of IPA is realized. Bi-functionality of metal state, acidity of support and nature of alcohol are perceived to be responsible for the variation in activity.

10aCatalytic transfer hydrogenation (CTH)10aCyclohexanol10aHydrodeoxygenation10alignin10aSupported metal catalysts1 aSingh, Dheerendra1 aDhepe, Paresh, L. uhttps://library.ncl.res.in/content/efficient-catalytic-transfer-hydrogenation-hydrodeoxygenation-lignin-derived-monomers01967nas a2200229 4500008004100000022001400041245013600055210006900191260000800260490000700268520116500275653002501440653001101465653001301476653001701489653001101506100002201517700002801539700001801567700002201585856013001607 2025 eng d a1867-388000aContinuous flow hydrodeoxygenation of lignin-derived guaiacol to cyclohexanol over durable Al2O3 hollow fiber supported co catalyst0 aContinuous flow hydrodeoxygenation of ligninderived guaiacol to  cSEP0 v173 a

The drive to decarbonize the chemical, oil, and gas industries through use of bio-derived resources is intensifying. This study focuses on converting lignin-derived phenolic compounds into cyclohexanol, a precursor for adipic acid production. The alumina hollow fiber supported cobalt catalyst (5Co/AHF@capillary) prepared by capillary action method was found to consist cobalt in both metallic and +delta oxidation states. Initial tests in a batch-mode reactor showed promising results, with 5Co/AHF@capillary catalyst demonstrating catalytic activity comparable to Ru/Al2O3 systems (225 degrees C, 1 MPa H-2, 4 h), achieving similar to 86% cyclohexanol yield in guaiacol hydrodeoxygenation reactions. The catalytic system was then adapted for continuous flow reactors under milder conditions (300 degrees C, 2.5 MPa H-2, 18 mL min(-1)), resulting in 83% guaiacol conversion and 74% cyclohexanol yield. The durability of the catalyst was checked for >80 h and results claim that catalyst was active in yielding consistent results. The roles of catalyst preparation method, hydrogen pressure, solvent, WHSV were thoroughly checked and discussed.

10abiomass valorization10aCarbon10aCo/Al2O310aCyclohexanol10alignin1 aSingh, Dheerendra1 aJogdand, Shunottara, M.1 aDevi, Nandini1 aDhepe, Paresh, L. uhttps://library.ncl.res.in/content/continuous-flow-hydrodeoxygenation-lignin-derived-guaiacol-cyclohexanol-over-durable-al2o3