02677nas a2200253   4500008004100000022001400041245010700055210006900162260009500231300001200326490000800338520173800346653000602084653001402090653002102104653002802125653002102153653002302174653001202197100002502209700003002234700003302264856012602297       2006                        eng d  a0021-951700aSelective ortho-methylation of phenol with methanol over copper manganese mixed-oxide spinel catalysts0 aSelective orthomethylation of phenol with methanol over copper m  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcOCT  a278-2910 v2433 a<p>Methylation of phenol with methanol as an alkylating agent to produce 2,6-xylenol was investigated over copper manganese mixed oxide spinels, CuxMn3-xO4 (x = 0, 0.25, 0.5, 0.75, and 1) prepared through co-precipitation. The catalytic activity strongly depends on the composition, acid-base properties, and structural stability. Various parameters, including catalyst composition, reaction temperature, feed composition, and durability of the catalyst during methylation, were investigated. Mainly o-cresol and 2,6-xylenol, along with small amounts of mesitol, were found in the product. A high ortho-selectivity of 100%, with 2,6-xylenol selectivity of 74%, was observed over Cu0.25Mn2.75O4 at 673 K. These catalysts were investigated using various techniques, including BET surface area, XRD, DRS UV-vis, TPD of NH3 and CO2, TPR, and X-ray photoemission spectroscopy (XPS). Powder XRD of the catalysts revealed the formation of copper-manganese spinels with hausmannite (Mn3O4) tetragonal structure, for x = 0-0.5, whereas an increase in copper content (x &gt; 0.5) led to the formation of cubic Cu1.5Mn1.5O4 phase. DRS UV-vis, and FTIR further supported the changes in structural phases observed by XRD. Temperature-programmed desorption Of CO2 and NH3 showed that the catalysts have strong basicity along with weak acidity when x = 0 and 0.25. XPS and XAES analysis revealed the presence of only Cu2+ ions in fresh sample with x = 0.25, whereas for x = 1.0, both Cu1+ and Cu2+ were observed. The deactivation of the catalysts is attributed to structural changes occurring during the reaction. Catalytic activity is correlated with structure, as well as with acid-base properties. (c) 2006 Elsevier Inc. All rights reserved.</p>10a210a6-xylenol10aacidity-basicity10acopper-manganese oxides10aortho-alkylation10aphenol methylation10aSpinels1 aReddy, Satyanarayana1 aGopinath, Chinnakonda, S.1 aChilukuri, Satyanarayana, V.  uhttps://library.ncl.res.in/content/selective-ortho-methylation-phenol-methanol-over-copper-manganese-mixed-oxide-spinel-002147nas a2200265   4500008004100000022001400041245008300055210006900138260010100207300001200308490000800320520121000328653000601538653002001544653003001564653002901594653001601623653001301639100001901652700002601671700002201697700001901719700003301738856011001771       2014                        eng d  a0974-362600aNovel catalysts for valorization of biomass to value-added chemicals and fuels0 aNovel catalysts for valorization of biomass to valueadded chemic  aC V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIAbCatalysis Soc IndiacMAR  a403-4130 v1263 a<p>Key furan compounds such as 5-hydroxymethylfurfural (HMF), 2,5-furandicarboxylic acid (FDCA) and 2,5-dimethylfuran (DMF) were synthesized from renewable feedstocks. Dehydration of fructose was carried out in biphasic conditions employing several solid acid catalysts by targeting selective formation of HMF. Its selectivity is linearly dependent on total acidity clearly revealing that lower acidity favours selective formation of HMF. Oxidation and hydrogenolysis of HMF has been explored using 2 wt% Ru-K-OMS-2. The catalysts used for each transformation were subjected to detailed characterization using XRD, BET surface area, temperature-programmed desorption and transmission electron microscopy. The effect of various reaction parameters was also investigated for obtaining high yields of desired chemical intermediates. High FDCA yields of 93.4 mol% and 66 mol% were achieved in alkaline and base-free conditions, respectively. The 2 wt% Ru-K-OMS-2 is a versatile catalyst as it also catalyses HMF hydrogenolysis giving 33 mol% of DMF. Thus, utility of various novel materials as catalysts has been demonstrated in the multistep transformations of hexoses to furan-based fuels and chemicals.</p>10a210a5-dimethylfuran10a5-furan dicarboxylic acid10a5-hydroxymethyl furfural10adehydration10afructose1 aLucas, Nishita1 aKanna, Narasimha, Rao1 aNagpure, Atul, S.1 aKokate, Ganesh1 aChilukuri, Satyanarayana, V.  uhttps://library.ncl.res.in/content/novel-catalysts-valorization-biomass-value-added-chemicals-and-fuels-0