01163nas a2200157 4500008004100000022001400041245012000055210006900175260011000244300001400354490000700368520044900375100002100824700002900845856013100874 2014 eng d a1463-926200aTowards efficient synthesis of sugar alcohols from mono- and poly-saccharides: role of metals, supports & promoters0 aTowards efficient synthesis of sugar alcohols from mono and poly aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAUG a4944-49540 v163 a

{Biomass derived sugar alcohols (xylitol, arabitol) find numerous uses in the food, oral hygiene and pharmaceutical industries. Their direct synthesis from poly-saccharides, however, still remains an immense challenge. In this study, we demonstrate in detail the effects of metals, supports and promoters in enhancing the yields of sugar alcohols from mono- and poly-saccharides. We undertook synthesis of bimetallic catalysts, M-M'/S (M

1 aTathod, Anup, P.1 aDhepe, Paresh, Laxmikant uhttps://library.ncl.res.in/content/towards-efficient-synthesis-sugar-alcohols-mono-and-poly-saccharides-role-metals-supports-001944nas a2200217 4500008004100000022001400041245011800055210006900173260009900242300001000341490000800351520108300359653002301442653002401465653001801489653002001507653002001527100002101547700002901568856012901597 2015 eng d a0960-852400aEfficient method for the conversion of agricultural waste into sugar alcohols over supported bimetallic catalysts0 aEfficient method for the conversion of agricultural waste into s aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcFEB a36-440 v1783 a

Promoter effect of Sn in the PtSn/gamma-Al2O3 (AL) and PtSn/C bimetallic catalysts is studied for the conversion of variety of substrates such as, C5 sugars (xylose, arabinose), C6 sugars (glucose, fructose, galactose), hemicelluloses (xylan, arabinogalactan), inulin and agricultural wastes (bagasse, rice husk, wheat straw) into sugar alcohols (sorbitol, mannitol, xylitol, arabitol, galactitol). In all the reactions, PtSn/AL showed enhanced yields of sugar alcohols by 1.5-3 times than Pt/AL. Compared to C, AL supported bimetallic catalysts showed prominent enhancement in the yields of sugar alcohols. Bimetallic catalysts characterized by X-ray diffraction study revealed the stability of catalyst and absence of alloy formation thereby indicating that Pt and Sn are present as individual particles in PtSn/AL. The TEM analysis also confirmed stability of the catalysts and XPS study disclosed formation of electron deficient Sn species which helps in polarizing carbonyl bond to achieve enhanced hydrogenation activity. (C) 2014 Elsevier Ltd. All rights reserved.

10aAgricultural waste10aBimetallic catalyst10aHydrogenation10aMonosaccharides10aPolysaccharides1 aTathod, Anup, P.1 aDhepe, Paresh, Laxmikant uhttps://library.ncl.res.in/content/efficient-method-conversion-agricultural-waste-sugar-alcohols-over-supported-bimetallic-011157nas a2200217 45000080041000000220014000412450135000552100069001902600008002593000011002674900008002785201038200286653002410668653001810692653001810710653001010728653001910738100002110757700002210778856013910800 2021 eng d a0008-621500aElucidating the effect of solid base on the hydrogenation of C5 and C6 sugars over Pt–Sn bimetallic catalyst at room temperature0 aElucidating the effect of solid base on the hydrogenation of C5  cJUL a1083410 v5053 a

Conversion of sugars into sugar alcohols at room temperature with exceedingly high yields are achieved over Pt–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–Sn/γ-Al2O3 catalysts were evaluated for hydrogenation of sugars. Amongst all combinations, the mixture (1:1 wt/wt) of Pt–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–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.

10aBimetallic catalyst10aHydrogenation10aHydrotalcites10aSugar10aSugar alcohols1 aTathod, Anup, P.1 aDhepe, Paresh, L. uhttps://library.ncl.res.in/content/elucidating-effect-solid-base-hydrogenation-c5-and-c6-sugars-over-pt%E2%80%93sn-bimetallic-catalyst