02878nas a2200277   4500008004100000022001400041245014900055210006900204260000800273300001600281490000600297520188700303653003702190653001702227653000802244653002302252653001302275653002002288653003002308100002502338700002202363700002902385700002602414700002902440856013102469       2021                        eng d  a2168-048500aMechanistic investigations on the catalytic transfer hydrogenation of lignin-derived monomers over Ru catalysts: theoretical and kinetic studies0 aMechanistic investigations on the catalytic transfer hydrogenati  cOCT  a14040-140500 v93 aThe hydrodeoxygenation (HDO) reaction of oxygenated compounds such as lignin-derived phenolics is well studied using molecular H-2 as a hydrogen source, yet the use of high pressures discourages its use on an industrial scale. As an alternative, the catalytic transfer hydrogenation (CTH) pathway provides in situ hydrogenation species, which reduces the need for the high-pressure infrastructure required when molecular hydrogen is used. Nevertheless, this strategy is scantly studied, and in lieu with this, herein we report the kinetic and mechanistic investigations of the CTH strategy for the HDO of guaiacol, phenol, anisole veratrole, and eugenol to their respective products. For potential commercialization purposes, low loading of metal, milder reaction conditions, and high selectivity toward desired products with a high H/C ratio were considered while designing catalysts (0.5 wt % Ru on SiO2-Al2O3, SiO2, Al2O3-acidic, Al2O3-basic, and Al2O3-neutral) for these reactions. As high as 74% cyclohexanol yield from guaiacol was achieved at 225 degrees C in the presence of isopropyl alcohol (IPA) as the hydrogen source and over the Ru/Al2O3-acidic catalyst reduced at 150 degrees C. A detailed kinetic study is carried out to understand the interaction of the substrate and intermediates with the catalyst and the influence of reaction parameters on the product formation. It was observed that the cisisomer of 2-methoxycyclohexanol rapidly undergoes further conversion than the trans-isomer. The experimental observations are substantiated through density functional theory (DFT) studies on Ru(0001) and guaiacol molecule complexes. DFT studies indicate that the adsorption of the cis-isomer is more exothermic as compared to that of the trans counterpart, and the underlying electronic factors are elucidated using charge density difference and density of states plots.10acatalytic transfer hydrogenation10aCyclohexanol10aDFT10aHydrodeoxygenation10akinetics10alignin monomers10aSupported metal catalysts1 aKhan, Tufeil, Sartaj1 aSingh, Dheerendra1 aSamal, Pragnya, Paramita1 aKrishnamurty, Sailaja1 aDhepe, Paresh, Laxmikant  uhttps://library.ncl.res.in/content/mechanistic-investigations-catalytic-transfer-hydrogenation-lignin-derived-monomers-over-ru02151nas a2200169   4500008004100000022001400041245008200055210006900137260000800206300001400214490000700228520157200235100002101807700002501828700002201853856010601875       2023                        eng d  a1144-054600aDesigning an industrially viable bimetallic catalyst for the polyol synthesis0 aDesigning an industrially viable bimetallic catalyst for the pol  cAPR  a7548-75550 v473 a<p>
	Designing new catalysts for the hydrogenation of sugars is important since the conventional catalyst RANEY (R) Ni faces issues such as leaching, operation under severe conditions (similar to 100 bar H-2) to achieve better yields and formation of complexes of Ni with polyols. To overcome these issues and to have an industrially acceptable methodology, bimetallic catalysts with varying metal loadings (Ru = 1.5 and 2 wt% and Co = 1.5, 3, and 4 wt%) were synthesized in the current work and their hydrogenation activities were evaluated for the synthesis of sugar alcohols from various sugars. It was revealed that the nature of the support plays an important role in deciding the selectivity and activity of the catalyst and amongst all the supports, basic alumina showed the best activity due to its contribution to the ring opening of sugars. C5 and C6 sugars were successfully hydrogenated to their respective sugar alcohols under low H-2 pressures (15 bar) and it was observed that as compared to the monometallic (1.5)Ru/Al-Basic catalyst, the bimetallic (1.5)Ru(3)Co/Al-Basic catalyst showed enhancement in the activity by almost 1.5 times. The improvement in the activity is suggested to be due to (i) observance of the synergistic effect between the base metal (Ru) and the promoter metal (Co); (ii) effect of basicity of the support; and (iii) electronic effect of Ru and Co. Recyclability of the catalysts and their efficiency to hydrogenate higher concentration substrate solutions (10-20 wt%) make the overall process industrially attractive.</p>
1 aKadam, Jyoti, R.1 aKhan, Tufeil, Sartaj1 aDhepe, Paresh, L.  uhttps://library.ncl.res.in/content/designing-industrially-viable-bimetallic-catalyst-polyol-synthesis02071nas a2200205   4500008004100000022001400041245015900055210006900214260000800283300001200291490000800303520129000311100002401601700001801625700002501643700001901668700001801687700002901705856013101734       2024                        eng d  a0970-414000aExploring thermocatalytic pyrolysis to derive sustainable chemical intermediates from plastic waste; role of temperature, catalyst, and reactor conditions0 aExploring thermocatalytic pyrolysis to derive sustainable chemic  cAPR  a383-3940 v1043 a<p>
	Plastic waste is a growing concern globally on account of the increasing use of plastic worldwide, compounded by single-use applications, poor waste collection and management practices, and its consequent leakage into the environment. In addition, plastics are derived from non-renewable fossil resources, and their growing demand is also partly responsible for greenhouse gas emissions and climate change. The aim of this paper is to explore the potential of plastic waste as a material resource, and thermocatalytic pyrolysis as a recycling process, to produce aliphatic and aromatic hydrocarbons, which are important chemical intermediates for various industries. We show that plastic pyrolysis can achieve a high yield of liquid hydrocarbons (similar to 80%) with a suitable distribution of aliphatic and aromatic compounds, by using different pyrolysis conditions and a catalyst. Specifically, this paper demonstrates the possibility of deriving two key classes of hydrocarbons, i.e., aliphatic (C10-C20 hydrocarbons) and aromatic hydrocarbons (xylene, toluene and benzene derivatives) with a yield of similar to 80% liquid hydrocarbons via catalytic pyrolysis. We also briefly discuss the challenges and opportunities, and the environmental and economic implications.</p>
1 aVenkataraghavan, R.1 aBhure, Arvind1 aKhan, Tufeil, Sartaj1 aShikare, Dipak1 aDevi, Nandini1 aDhepe, Paresh, Laxmikant  uhttps://library.ncl.res.in/content/exploring-thermocatalytic-pyrolysis-derive-sustainable-chemical-intermediates-plastic-waste