@article {47731,
	title = {Selective production of C9 monomeric phenols via hydrogenolysis of lignin using Pd-(W/Zr/Mo oxides)-supported on biochar catalyst},
	journal = {Fuel},
	volume = {308},
	year = {2022},
	month = {JAN },
	pages = {121818},
	type = {Article},
	abstract = {Valorizing 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.},
	keywords = {Activated biochar, Guaiacol, Hydrogenolysis, lignin, Metal oxides, Palladium},
	issn = {0016-2361},
	doi = {10.1016/j.fuel.2021.121818},
	author = {Gurrala, Lakshmiprasad and Kumar, M. Midhun and Sharma, Shweta and Paek, Changyub and Vinu, R.}
}
@article {49908,
	title = {Hydrodeoxygenation of guaiacol to cyclohexanol using noble metal-supported Ni-based perovskite-derived catalysts},
	journal = {ChemCatChem},
	volume = {17},
	year = {2025},
	month = {AUG},
	type = {Article},
	abstract = {<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>
},
	keywords = {Cyclohexanol, Guaiacol, Hydrodeoxygenation, In-situ DRIFT, Ni-based perovskites},
	issn = {1867-3880},
	doi = {10.1002/cctc.202500577},
	author = {Marimuthu, Prabu and Raja, Thirumalaiswamy and Vinu, Ravikrishnan}
}
