@article {47439, title = {Elucidating the effect of solid base on the hydrogenation of C5 and C6 sugars over Pt{\textendash}Sn bimetallic catalyst at room temperature}, journal = {Carbohydrate Research}, volume = {505}, year = {2021}, month = {JUL}, pages = {108341}, type = {Article}, abstract = {

Conversion of sugars into\ sugar alcohols\ at room temperature with exceedingly high yields are achieved over Pt{\textendash}Sn/γ-Al2O3\ catalyst in the presence of calcined\ hydrotalcite. pH of the reaction mixture significantly affects the conversion and selectivity for sugar alcohols. Selection of a suitable base is the key to achieve optimum yields. Various solid bases in combination with Pt{\textendash}Sn/γ-Al2O3\ catalysts were evaluated for hydrogenation of sugars. Amongst all combinations, the mixture (1:1\ wt/wt) of Pt{\textendash}Sn/γ-Al2O3\ and calcined hydrotalcite showed the best results. Hydrotalcite helps to make the pH of reaction mixture alkaline at which sugar molecules undergo ring opening. The sugar molecule in open chain form has\ carbonyl group\ which can be polarized by Sn in Pt{\textendash}Sn/γ-Al2O3\ and Pt facilitates the hydrogenation. In the current work, effect of both; solid base and Sn as a promoter has been studied to improve the yields of sugar alcohols from various C5 and C6 sugars at very mild reaction conditions.

}, keywords = {Bimetallic catalyst, Hydrogenation, Hydrotalcites, Sugar, Sugar alcohols}, issn = {0008-6215}, doi = {10.1016/j.carres.2021.108341}, author = {Tathod, Anup P. and Dhepe, Paresh L.} } @article {47679, title = {Upgrading lignin derived monomers over basic supported metal catalysts}, journal = {Fuel}, volume = {306}, year = {2021}, month = {DEC}, pages = {121588}, type = {Article}, abstract = {Catalytic upgradation of aromatic monomers derived from lignin depolymerization is of high interest for the production of sustainable fuels and chemicals. Basic support has potential to provide advantages of better substrate-support interaction and reduced coke formation. Hence, we report the effect of various basic supports for metal catalysts (Pt, Pd, Ru) on the upgradation of phenol, guaiacol and eugenol. The complete hydrogenation product is achieved due to the strong interaction of the substrate with catalyst. Phenol is converted (55\%) into cyclohexanol (49\% yield) with low loading of Pt catalyst (1 wt\%), supported by the higher TON of 1 wt\% Pt/NaX (TON = 14844) than 3 wt\% Pt/NaX (TON = 5128). Effect of basic support with moderate (NaX) and strong (CHT) basic strengths are corelated for the higher cyclohexanone formation. Presence of strong basic sites and higher TON of 3 wt\% C-HT (TON = 6806) directs the significant substrate-support interaction. Catalytic activity and recyclability are supported by the comparable performance of recycle runs and characterizations of the fresh and spent catalysts.}, keywords = {aromatic monomers, Hydrogenation, lignin, Solid bases, supported metal catalyst, Upgradation}, issn = {0016-2361}, doi = {10.1016/j.fuel.2021.121588}, author = {Chaudhary, Richa and Dhepe, Paresh L.} }