01104nas a2200169 4500008004100000022001400041245011300055210006900168260011000237300001400347490000600361520036600367100002300733700002000756700002900776856012900805 2014 eng d a2044-475300aSilica and zirconia supported tungsten, molybdenum and gallium oxide catalysts for the synthesis of furfural0 aSilica and zirconia supported tungsten molybdenum and gallium ox aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUN a2904-29070 v43 a

SiO2 and ZrO2 supported W, Mo and Ga oxide catalysts were prepared by a sol-gel and wet-impregnation method. The 10 wt% WO3/SiO2 (sol-gel) catalyst showed 61 +/- 2% furfural yield from hemicellulose in a one-pot fashion for at least 8 cycles. Based on XRD, TPD and Hammett acidity characterizations, the catalyst structure-activity correlation was drawn.

1 aBhaumik, Prasenjit1 aKane, Tanushree1 aDhepe, Paresh, Laxmikant uhttps://library.ncl.res.in/content/silica-and-zirconia-supported-tungsten-molybdenum-and-gallium-oxide-catalysts-synthesis-001925nas a2200241 4500008004100000022001400041245008700055210006900142260007300211300001000284490000800294520109600302653001801398653001401416653001501430653001101445653003001456100001701486700002001503700001801523700002901541856011301570 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

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.

10aHydrogenation10aOxidation10aSolid base10aSugars10aSupported metal catalysts1 aTathod, Anup1 aKane, Tanushree1 aSanil, E., S.1 aDhepe, Paresh, Laxmikant uhttps://library.ncl.res.in/content/solid-base-supported-metal-catalysts-oxidation-and-hydrogenation-sugars-002356nas a2200253 4500008004100000022001400041245011800055210006900173260010100242300001200343490000800355520142000363653002201783653001201805653001101817653001801828653001101846653002401857100002301881700002401904700002001928700002901948856012501977 2014 eng d a0974-362600aValue addition to lignocellulosics and biomass-derived sugars: an insight into solid acid-based catalytic methods0 aValue addition to lignocellulosics and biomassderived sugars an  aC V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIAbCatalysis Soc IndiacMAR a373-3850 v1263 a

For the synthesis of important platform chemicals such as sugars (xylose and arabinose) and furans (furfural and 5-hydroxymethylfurfural (HMF)) from carbohydrates (hemicellulose and fructose) solid acid catalysts are employed. Similarly, over solid acid catalysts, conversion of lignin into aromatic monomers is performed. It is observed that in the dehydration of fructose, because of higher hydrothermal stability, silicoaluminophosphate (SAPO) catalysts give better activity (78% HMF yield) compared with other solid acid catalysts (<63% HMF yield) at 175 degrees C. Particularly, SAPO-44 catalyst can be reused at least 5 times with marginal decrease in the activity. Zeolite, BUSY (Si/Al = 15) is active in the conversion of isolated (pure) hemicellulose to produce 41% C-5 sugars in water. The catalyst is also active in the selective conversion of hemicellulose from bagasse to yield 59% C-5 sugars. It is possible to obtain high yields of furfural (54%) directly from bagasse if instead of water, Water+toluene solvent system is used. Depolymerization of lignin using HUSY catalyst produced aromatic monomers with 60% yield at 250 degrees C. A detailed catalyst characterization study is performed to understand the correlation between catalyst activity and morphology. To understand the effect of impurities present in the substrate over solid acid catalysts, metal-exchange study is carried out.

10aaromatic monomers10aBiomass10afurans10aHemicellulose10alignin10asolid acid catalyst1 aBhaumik, Prasenjit1 aDeepa, Ayillath, K.1 aKane, Tanushree1 aDhepe, Paresh, Laxmikant uhttps://library.ncl.res.in/content/value-addition-lignocellulosics-and-biomass-derived-sugars-insight-solid-acid-based-0