02665nas a2200241   4500008004100000022001400041245012800055210006900183260007400252300001200326490000800338520179600346653001202142653000902154653002002163653002702183653000802210653001702218653001402235100002002249700002902269856012502298       2014                        eng d  a1878-519000aSynthesis of 2,5-furandicarboxylic acid by the aerobic oxidation of 5-hydroxymethyl furfural over supported metal catalysts0 aSynthesis of 25furandicarboxylic acid by the aerobic oxidation o  aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcJUN  a173-1870 v1123 a<p>Supported Pt catalysts are synthesized, characterized and are used in the liquid phase air oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). Under the optimum reaction conditions of a stepwise increase in the reaction temperature (75 and 140 degrees C for 12 h each), we achieved as high as 96 % FDCA yield in presence of 1 bar oxygen pressure over Pt/c-Al2O3. It is shown that as the oxygen pressure increases (1-10 bar), the FDCA yields decrease, since at higher partial pressure of oxygen, overoxidation reactions of substrate and product(s) are possible. It is interesting to note that even with air as an oxidant, we obtained similar yields of FDCA as that with oxygen. Moreover, the effects of base (weak or strong), its concentration (equimolar or excess) were studied in detail. It is important to increase the reaction temperature in a stepwise manner to achieve higher yields of FDCA since at higher temperatures HMF undergoes self-degradation and thus the yields of FDCA decrease. The self-degradation of HMF is also proved by undertaking the reaction under nitrogen environment. The study on the effect of substrate-to-catalyst ratio is done to improve up on the economics of overall process. The effect of supports (reducible and non-reducible) and their oxygen storage capacity is discussed and is proposed to be one of the factors to change the course of reaction. Furthermore, we have shown that FDCA formed in the reaction can be successfully isolated (91 %, isolated yield) in the pure form and its purity is confirmed by NMR, melting point, and elemental analysis. The catalysts were characterized with X-ray powder diffraction, transmission electron microscopy and inductively coupled plasma-optical emission spectroscopy techniques.</p>10aBiomass10aFDCA10agreen chemistry10aheterogeneous catalyst10aHMF10aImpregnation10aOxidation1 aSahu, Ramakanta1 aDhepe, Paresh, Laxmikant  uhttps://library.ncl.res.in/content/synthesis-25-furandicarboxylic-acid-aerobic-oxidation-5-hydroxymethyl-furfural-over-001746nas a2200253   4500008004100000022001400041245006400055210006400119260008600183300001100269490000700280520093000287653002301217653001801240653001401258653001101272653001301283653001901296653000801315653002401323100002301347700002901370856009301399       2016                        eng d  a0161-494000aSolid acid catalyzed synthesis of furans from carbohydrates0 aSolid acid catalyzed synthesis of furans from carbohydrates  a530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USAbTAYLOR & FRANCIS INCcJAN  a36-1120 v583 a<p>The alternative feedstock, biomass (particularly lignocelluloses), having the profuse availability, is promising for the synthesis of several value-added chemicals which are currently obtained from fossil feedstock. In this article, the synthesis of two extremely significant furan chemicals viz. furfural and 5-hydroxymethylfurfural (HMF) are discussed. In the synthesis of furans from biomass, numerous challenges, i.e., use of edible sugars as substrates, selectivity to furans, their isolation in pure form, reuse of catalyst, environmental issues, etc., are perceived and in the recent past researchers tried to resolve those by developing advance methodologies. This article comprehensively summarizes the latest progress made in the above-mentioned areas and also provides commentary on the analyses of results, rationale for observed activity and mechanisms, etc. It also discusses future aspects of this work.</p>10aBiomass conversion10acarbohydrates10acellulose10afurans10afurfural10ahemicelluloses10aHMF10asolid acid catalyst1 aBhaumik, Prasenjit1 aDhepe, Paresh, Laxmikant  uhttps://library.ncl.res.in/content/solid-acid-catalyzed-synthesis-furans-carbohydrates-0