02328nas a2200157   4500008004100000245006600041210006600107260000800173300003200181490000800213520181200221100001302033700001402046700001502060856009502075       2019                        eng d00aKinetics of cinnamaldehyde hydrogenation in four phase system0 aKinetics of cinnamaldehyde hydrogenation in four phase system  cDEC  aArticle Number: UNSP 1205120 v3773 a<p>The kinetics of cinnamaldehyde hydrogenation in four phase system viz. gas (hydrogen)-liquid (cinnamaldehyde + toluene)-liquid (aqueous KOH)-solid (catalyst, 5% Pt/C), [GLLS] system has been studied in this work. As reported, addition of aqueous alkali in hydrogenation of unsaturated aldehydes like cinnamaldehyde shifts selectivity towards unsaturated alcohol, cinnamyl alcohol. The promotion action by alkali metals for improving selectivity towards cinnamyl alcohol involves changes in the adsorption mechanism of the cinnamaldehyde in a way that CO bond get preferentially hydrogenated. In cinnamaldehyde hydrogenation in presence of promoters two different catalytic sites can be considered, each for CO and CC bond hydrogenation. In accordance with this consideration and as demonstrated in various studies on hydrogenation of unsaturated aldehydes, further hydrogenation of intermediate-cinnamyl alcohol (CC bond hydrogenation) occurs on Pt only sites while cinnamaldehyde and intermediate hydrocinnamaldehyde (both involving CO bond hydrogenation) are hydrogenated on catalytic sites affected by promoters. This preferential adsorption and hydrogenation through CO bond leads to the increased selectivity of cinnamyl alcohol. Although, many authors have studied cinnamaldehyde hydrogenation using various promoters, there are very few reports on kinetics in which this two site approach behind promotion action has been considered. The effect of various operating parameters on the rates of hydrogenation was studied and the two site Langmuir-Hinshelwood type of kinetic model was used for evaluating the kinetic parameters by fitting experimental data. The thermodynamic model for estimating the solubility of hydrogen in the reaction mixture was incorporated with this kinetic model.</p>
1 aKhan, M.1 aJoshi, S.1 aRanade, V.  uhttps://library.ncl.res.in/content/kinetics-cinnamaldehyde-hydrogenation-four-phase-system02339nas a2200349   4500008004100000022001400041245011900055210006900174260000800243300001400251490000700265520127700272653001301549653001701562653003501579653002401614653000801638100001501646700002001661700001501681700001901696700001801715700001501733700001901748700001401767700002001781700001301801700001701814700001501831700001201846856013101858       2019                        eng d  a0272-884200aRole of Li+ and Fe3+ in modified ZnO: Structural, vibrational, opto-electronic, mechanical and magnetic properties0 aRole of Li and Fe3 in modified ZnO Structural vibrational optoel  cJAN  a7232-72430 v453 aWhen Fe is doped in ZnO, a situation of charge imbalance is created due to the higher charge of Fe3+. A charge balance may be obtained by co-doping Li+0.5Fe3+0.5 combinations. A solid solution of Zn1-x(Fe0.5Li0.5)xO (0 ≤ x ≤ 0.03125) is synthesized with this viewpoint. The crystallites belong to a wurtzite P63mc space group, with lattice parameters a, b and c increasing nominally for x = 0.0156 and thereafter remaining invariant. The size varies in the range ~ 60–142 nm. Interstitials of Li and Zn ions are formed. Along with Fe3+ substitution these defects are reasons for O interstitials. These oxygen interstitials increase the red emission while reduction of oxygen vacancies reduces the green emission. These point defects create structural distortion and strain which can generate Zn vacancies. Bandgap reduces due to shallow defects. Mid-bandgap states due to oxygen interstitials and Fe 3d-O 2p hybridization result in NIR emission. On the other hand the crystal surface deforms due to Li addition which hardens the materials. A weak ferromagnetism appears at very low temperature which is enhanced by Li+ addition. Long range exchange mechanism between Fe3+ ions appears in the samples, mediated by magnetic polarons due to point defects.10ahardness10aNIR emission10aShallow and deep level defects10aWeak ferromagnetism10aZnO1 aBajpai, G.1 aMoirangthem, I.1 aSarkar, S.1 aBarman, S., R.1 aVinod, C., P.1 aBajpai, S.1 aRiyajuddin, S.1 aGhosh, K.1 aBasaula, D., R.1 aKhan, M.1 aLiu, S., -W.1 aBiring, S.1 aSen, S.  uhttps://library.ncl.res.in/content/role-li-and-fe3-modified-zno-structural-vibrational-opto-electronic-mechanical-and-magnetic