02467nas a2200265   4500008004100000022001400041245013400055210006900189260000900258300001100267490000800278520159800286653002201884653001301906653001901919653001101938653001701949653001401966100002701980700001802007700001902025700001902044700001302063856012502076       2022                        eng d  a0016-236100aSelective production of C9 monomeric phenols via hydrogenolysis of lignin using Pd-(W/Zr/Mo oxides)-supported on biochar catalyst0 aSelective production of C9 monomeric phenols via hydrogenolysis   cJAN   a1218180 v3083 aValorizing lignin to phenolic monomers and fine chemicals is an essential component of a sustainable biorefinery that uses lignocellulosic feedstocks. In this study, Pd-metal oxides (ZrO2, WOx, MoO3) supported on activated biochar (ABC) catalysts were developed for hydrogenolysis of lignin. The metals (2% Pd, 5% Zr, 5% W, 5% Mo) were supported on activated biochar using the wetness impregnation method, and the catalysts were extensively characterized. The effect of addition of secondary metals on active surface properties such as acidity, Pd metal particle size and dispersion were also evaluated. The selectivity to C9 monomeric phenols followed the trend: 2Pd-5Mo/ABC (57.3%) > 2Pd-5Zr/ABC (49.2%) > 2Pd-5W/ABC (45%) > 2Pd/ABC (42.9%). The maximum C9 phenolic monomer yield achieved in this study was similar to 22 wt%. The fractional conversion of lignin was 67-69% with Pd-metal oxide catalysts. The presence of Mo in the catalyst inhibited the hydrogenation of aliphatic C-alpha = C-beta in lignin and led to the formation of t-isoeugenol, while the presence of W and Zr resulted in selective formation of the hydrogenated product, propyl guaiacol. Using model compounds, it is proved that the formation of propyl guaiacol is via hydrogenation of t-isoeugenol, and not through dehydroxylation of propanol guaiacol. The dehydroxylation activity of the catalysts is attributed to the higher Lewis acidity and electropositive nature of the metals. A notable carbon atom economy of 47-50% towards total phenolic monomers was achieved with 2Pd/ABC, 2Pd-5Mo/ABC and 2Pd-5Zr/ABC catalysts.10aActivated biochar10aGuaiacol10aHydrogenolysis10alignin10aMetal oxides10aPalladium1 aGurrala, Lakshmiprasad1 aKumar, Midhun1 aSharma, Shweta1 aPaek, Changyub1 aVinu, R.  uhttps://library.ncl.res.in/content/selective-production-c9-monomeric-phenols-hydrogenolysis-lignin-using-pd-wzrmo-oxides02324nas a2200217   4500008004100000022001400041245011700055210006900172260000800241490000700249520155600256653001701812653001301829653002301842653001801865653002501883100002101908700002601929700002301955856012801978       2025                        eng d  a1867-388000aHydrodeoxygenation of guaiacol to cyclohexanol using noble metal-supported Ni-based perovskite-derived catalysts0 aHydrodeoxygenation of guaiacol to cyclohexanol using noble metal  cAUG0 v173 a<p>
	This study focuses on the role of noble metal-doped Ni-based perovskites, specifically LaNiO3 and NiTiO3 catalysts in the hydrodeoxygenation (HDO) of guaiacol. The findings demonstrate that reduced Ru-LaNiO3 catalyst achieved superior performance with 100% guaiacol conversion and a 75% selectivity toward cyclohexanol, compared to reduced Ru-NiTiO3, which achieved only 43% conversion and 25% cyclohexanol selectivity under identical conditions (240 degrees C, 30 bar H2, and 4 h). High-resolution transmission electron microscopic (HR-TEM) analysis reveals that LaNiO3-supported catalysts exhibit better metal dispersion and smaller nickel nanoparticle sizes compared to NiTiO3-supported counterparts. X-ray photoelectron spectroscopy (XPS) analysis shows that the reduction of nickel and noble metals is more facile on LaNiO3. Additionally, the O 1s XPS profile for reduced Ru-LaNiO3 indicates a higher proportion of lattice oxygen (OLat similar to 79%) and a lower proportion of oxygen vacancies (OVac similar to 21%) compared to other catalyst systems. The optimized OLat/OVac ratio is shown to be critical for the effective HDO of guaiacol. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) demonstrates a high HDO reaction rate using reduced Ru-LaNiO3 than reduced Ru-NiTiO3, with cyclohexanol formation attributed to the keto-enol tautomerization pathway. Overall, this study underscores the critical roles of oxygen vacancies, metal dispersion, and metal-metal oxide interactions in the HDO of guaiacol.</p>
10aCyclohexanol10aGuaiacol10aHydrodeoxygenation10aIn-situ DRIFT10aNi-based perovskites1 aMarimuthu, Prabu1 aRaja, Thirumalaiswamy1 aVinu, Ravikrishnan  uhttps://library.ncl.res.in/content/hydrodeoxygenation-guaiacol-cyclohexanol-using-noble-metal-supported-ni-based-perovskite