01924nas a2200241   4500008004100000022001400041245008700055210006900142260007300211300001000284490000800294520109600302653001801398653001401416653001501430653001101445653003001456100001701486700002001503700001801523700002901541856011201570       2014                        eng d  a1381-116900aSolid base supported metal catalysts for the oxidation and hydrogenation of sugars0 aSolid base supported metal catalysts for the oxidation and hydro  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL  a90-990 v3883 a<p>Pt impregnated on gamma-Al2O3 (acidic support) and hydrotalcite (basic support) catalysts were synthesized, characterized and used in the oxidation and hydrogenation reactions of C5 and C6 sugars. In the absence of homogeneous base, 83% yield for gluconic acid; an oxidation product of glucose can be achieved over Pt/hydrotalcite (HT) catalyst at 50 degrees C under atmospheric oxygen pressure. Similarly, 57% yield for xylonic acid, an oxidation product of xylose is also possible over Pt/HT catalyst. Hydrogenation of glucose conducted using Pt/gamma-Al2O3 + HT catalytic system showed 68% sugar alcohols (sorbitol + mannitol) formation. The 82% yield for C5 sugar alcohols (xylitol + arabitol) was obtained by subjecting xylose to hydrogenation over Pt/gamma-Al2O3 + HT at 60 degrees C. UV analysis helped to establish the fact that under alkaline conditions sugars prefer to remain in open chain form in the solution and thus exposes -CHO group which further undergoes oxidation and hydrogenation reactions to yield acids and alcohols. (c) 2013 Elsevier B.V. All rights reserved.</p>10aHydrogenation10aOxidation10aSolid base10aSugars10aSupported metal catalysts1 aTathod, Anup1 aKane, Tanushree1 aSanil, E., S.1 aDhepe, Paresh, Laxmikant  uhttp://library.ncl.res.in/content/solid-base-supported-metal-catalysts-oxidation-and-hydrogenation-sugars-001943nas a2200217   4500008004100000022001400041245011800055210006900173260009900242300001000341490000800351520108300359653002301442653002401465653001801489653002001507653002001527100002101547700002901568856012801597       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<p>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.</p>10aAgricultural waste10aBimetallic catalyst10aHydrogenation10aMonosaccharides10aPolysaccharides1 aTathod, Anup, P.1 aDhepe, Paresh, Laxmikant  uhttp://library.ncl.res.in/content/efficient-method-conversion-agricultural-waste-sugar-alcohols-over-supported-bimetallic-0