01421nas a2200205   4500008004100000022001400041245005500055210005500110260007700165300001200242490000600254520073500260653001200995653001401007653002801021653002401049100002901073700002101102856009201123       2008                        eng d  a1864-563100aCellulose conversion under heterogeneous catalysis0 aCellulose conversion under heterogeneous catalysis  aPO BOX 10 11 61, D-69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcNOV  a969-9750 v13 a<p>In view of current problems such as global warming, high oil prices, food crisis, stricter environmental laws, and other geopolitical scenarios surrounding the use of fossil feedstocks and edible resources, the efficient conversion of cellulose, a non-food biomass, into energy, fuels, and chemicals has received much attention. The application of heterogeneous catalysis could allow researchers to develop environmentally benign processes that lead to selective formation of value-added products from cellulose under relatively mild conditions. This Minireview gives insight into the importance of biomass utilization, the current status of cellulose conversion, and further transformation of the primary products obtained</p>10aBiomass10acellulose10aheterogeneous catalysis10asupported catalysts1 aDhepe, Paresh, Laxmikant1 aFukuoka, Atsushi  uhttps://library.ncl.res.in/content/cellulose-conversion-under-heterogeneous-catalysis-001780nas a2200217   4500008004100000022001400041245006500055210006500120260006800185300001200253490000600265520104800271653001201319653001401331653001701345653002201362653002901384100002101413700002901434856009901463       2009                        eng d  a1527-899900aSustainable green catalysis by supported metal nanoparticles0 aSustainable green catalysis by supported metal nanoparticles  a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcAUG  a224-2350 v93 a<p>The recent progress of sustainable green catalysis by supported metal nanoparticles is described. The template synthesis of metal nanoparticles in ordered porous materials is studied for the rational design of heterogeneous catalysts capable of high activity and selectivity. The application of these materials in green catalytic processes results in a unique activity and selectivity arising from the concerted effect of metal nanoparticles and supports. The high catalytic performances of Pt nanoparticles in mesoporous silica is reported Supported metal catalysts have also been applied to biomass conversion by heterogeneous catalysis Additionally, the degradation of cellulose by supported metal catalysts, in which bifunctional catalysis of acid and metal plays the key role for the hydrolysis and reduction of cellulose, is also reported. (C) 2009 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 224-235: 2009: Published online in Wiley InterScience (www.intersciencewiley.corn) DOI 10.1002/tcr.200900004</p>10aBiomass10acellulose10aCO oxidation10aMesoporous silica10asupported metal catalyst1 aFukuoka, Atsushi1 aDhepe, Paresh, Laxmikant  uhttps://library.ncl.res.in/content/sustainable-green-catalysis-supported-metal-nanoparticles-002687nas a2200217   4500008004100000022001400041245013900055210006900194260007700263300001200340490000600352520183700358653002302195653001202218653001802230653002802248653001302276100002002289700002902309856013102338       2012                        eng d  a1864-563100aOne-Pot method for the selective conversion of hemicellulose from crop waste into C5 sugars and furfural by using solid acid catalysts0 aOnePot method for the selective conversion of hemicellulose from  aPO BOX 10 11 61, D-69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcAPR  a751-7610 v53 a<p>We present a solid-acid catalyzed one-pot method for the selective conversion of solid hemicellulose without its separation from other lignocellulosic components, such as cellulose and lignin. The reactions were carried out in aqueous and biphasic media to yield xylose, arabinose, and furfural. To overcome the drawbacks posed by mineral acid methods in converting hemicelllulose, we used heterogeneous catalysts that work at neutral pH. In a batch reactor, these heterogeneous catalysts, such as solid acids (zeolites, clays, metal oxides etc.), resulted in &gt;90% conversion of hemicellulose. It has been shown that the selectivity for the products can be tuned by changing the reaction conditions, for example, a reaction carried out in water at 170 degrees C for 1 h with HBeta (Si/Al=19) and HUSY (Si/Al=15) catalysts gave yields of 62 and 56% for xylose and arabinose, respectively. With increased reaction time (6 h) and in presence of only water, HUSY resulted in yields of 30% xylose+arabinose and 18% furfural. However, in a biphasic reaction system (water+p-xylene, 170 degrees C, 6 h) yields of 56% furfural with 17% xylose+arabinose could be achieved. It was shown that with the addition of organic solvent the furfural yield could be increased from 18 to 56%. Under optimized reaction conditions, &gt;90% carbon balance was observed. The study revealed that catalysts were recyclable with a 20% drop in activity for each subsequent run. It was observed that temperature, pressure, reaction time, substrate to catalyst ratio, solvent, and so forth had an effect on product formation. The catalysts were characterized by means of X-ray diffraction, temperature-programmed desorption of NH3, inductively coupled plasma spectroscopy, elemental analysis, and solid-state NMR (Si-29, Al-27) spectroscopy techniques.</p>10aanalytical methods10aBiomass10acarbohydrates10aheterogeneous catalysis10azeolites1 aSahu, Ramakanta1 aDhepe, Paresh, Laxmikant  uhttps://library.ncl.res.in/content/one-pot-method-selective-conversion-hemicellulose-crop-waste-c5-sugars-and-furfural-using-002665nas 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-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<p>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 (&lt;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.</p>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-001902nas a2200217   4500008004100000022001400041245009300055210006900148260007300217300001000290490000800300520114400308653001201452653001301464653001801477653001201495653001101507100002301518700002901541856011401570       2015                        eng d  a0920-586100aEffects of careful designing of SAPO-44 catalysts on the efficient synthesis of furfural0 aEffects of careful designing of SAPO44 catalysts on the efficien  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG  a66-720 v2513 a<p>Considering the growing importance of furfural, it is necessary to develop a robust solid acid catalyst for the conversion of xylan (hemicelluloses) into furfural in a one-pot method. In this study, the effects of various components (Si, Al and P) and crystallization time on the preparation of acidic materials and their properties are extensively described. It is seen that with the increase in crystallization time (0, 48, 96, 176 h) during the synthesis of silicoaluminophosphate (SAPO-44), materials morphology changes from amorphous to AFI to CHA and the best activity for furfural synthesis (82%) from xylan was observed with SAPO-44 catalyst aged for 176 h. Since, acidity in the SAPO-44 is guided by the incorporation of Si in the ALPO framework, study on Si molar concentration (0.8, 1.0, 1.2, 1.4 and 1.6) in SAPO-44 was carried out and it was observed that SAPO-44 having 1.0 mole of Si content is the best catalyst for the xylan/xylose conversion to furfural. Catalyst structure-activity correlation is thoroughly defined with the help of several physico-chemical properties. (C) 2014 Elsevier B.V. All rights reserved.</p>10aBiomass10afurfural10aHemicellulose10aSAPO-4410aXylose1 aBhaumik, Prasenjit1 aDhepe, Paresh, Laxmikant  uhttps://library.ncl.res.in/content/effects-careful-designing-sapo-44-catalysts-efficient-synthesis-furfural-002642nas a2200229   4500008004100000022001400041245007700055210006900132260007100201300001200272490000600284520184300290653002202133653001202155653002602167653002102193653001102214653002502225100002402250700002902274856010902303       2015                        eng d  a2155-543500aLignin depolymerization into aromatic monomers over solid acid catalysts0 aLignin depolymerization into aromatic monomers over solid acid c  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJAN  a365-3790 v53 a<p>It is imperative to develop an efficient and environmentally benign pathway to valorize profusely available lignin, a component of nonedible lignocellulosic materials, into value-added aromatic monomers, which can be used as fuel additives and platform chemicals. To convert lignin, earlier studies used mineral bases (NaOH, CsOH) or supported metal catalysts (Pt, Ru, Pd, Ni on C, SiO2, Al2O3, etc.) under a hydrogen atmosphere, but these methods face several drawbacks such as corrosion, difficulty in catalyst recovery, sintering of metals, loss of activity, etc. Here we show that under an inert atmosphere various solid acid catalysts can efficiently convert six different types of lignins into value-added aromatic monomers. In particular, the SiO2Al2O3 catalyst gave exceptionally high yields of ca. 60% for organic solvent soluble extracted products with 95 +/- 10% mass balance in the depolymerization of dealkaline lignin, bagasse lignin, and ORG and EORG lignins at 250 degrees C within 30 min. GC, GC-MS, HPLC, LC-MS, and GPC analysis of organic solvent soluble extracted products confirmed the formation of aromatic monomers with ca. 90% selectivity. In the products, confirmation of retention of aromatic nature as present in lignin and the appearance of several functional groups has been carried out by FT-IR and H-1 and C-13 NMR studies. Further, isolation of major products by column chromatography was carried out to obtain aromatic monomers in pure form and their characterization by NMR is presented. A detailed characterization of six different types of lignins obtained from various sources helped in substantiating the catalytic results obtained in these reactions. A meticulous study on fresh and spent catalysts revealed that the amorphous catalysts are preferred to obtain reproducible catalytic results.</p>10aaromatic monomers10aBiomass10acolumn chromatography10adepolymerization10alignin10asolid acid catalysts1 aDeepa, Ayillath, K.1 aDhepe, Paresh, Laxmikant  uhttps://library.ncl.res.in/content/lignin-depolymerization-aromatic-monomers-over-solid-acid-catalysts-0