<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sankar, M.</style></author><author><style face="normal" font="default" size="100%">Nair, C. Madhavan</style></author><author><style face="normal" font="default" size="100%">Murty, K. V. G. K.</style></author><author><style face="normal" font="default" size="100%">Manikandan, Palanichamy</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Transesterification of cyclic carbonates with methanol at ambient conditions over tungstate-based solid catalysts</style></title><secondary-title><style face="normal" font="default" size="100%">Applied Catalysis A-General</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dimethyl carbonate</style></keyword><keyword><style  face="normal" font="default" size="100%">ethylene carbonate</style></keyword><keyword><style  face="normal" font="default" size="100%">heterogeneous catalyst</style></keyword><keyword><style  face="normal" font="default" size="100%">Raman spectroscopy</style></keyword><keyword><style  face="normal" font="default" size="100%">sodium tungstate</style></keyword><keyword><style  face="normal" font="default" size="100%">transesterification</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">SEP</style></date></pub-dates></dates><publisher><style face="normal" font="default" size="100%">ELSEVIER SCIENCE BV</style></publisher><pub-location><style face="normal" font="default" size="100%">PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS</style></pub-location><volume><style face="normal" font="default" size="100%">312</style></volume><pages><style face="normal" font="default" size="100%">108-114</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Dimethyl carbonate synthesis with 80 mol% yield is achieved through transesterification of ethylene carbonate with methanol at ambient conditions (RT and atmospheric pressure) using alkali and alkaline-earth tungstates as solid catalysts. The catalysts are efficient even at the sub-ambient temperatures. Reactions under CO2 pressure indicate that CO2 atmosphere retards the transesterification reaction completely below 100 degrees C. Experimental conditions of 150 degrees C and 3.4 MPa CO2 pressure are required to obtain maximum DMC yield of 71 mol%. Synthesis of DMC by one-pot synthesis using epoxide, CO2 and methanol is not as effective as that by two-step method with the present catalyst system. Raman and IR spectra of methanol-interacting tungstates indicate the formation of a methoxide ion species adsorbed at the catalyst surface as one possible reaction intermediates. (C) 2006 Elsevier B.V. All rights reserved.&lt;/p&gt;</style></abstract><work-type><style face="normal" font="default" size="100%">Article</style></work-type><custom3><style face="normal" font="default" size="100%">&lt;p&gt;Foreign&lt;/p&gt;</style></custom3><custom4><style face="normal" font="default" size="100%">4.012</style></custom4></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Mapa, Maitri</style></author><author><style face="normal" font="default" size="100%">Thushara, K. S.</style></author><author><style face="normal" font="default" size="100%">Saha, Biswajit</style></author><author><style face="normal" font="default" size="100%">Chakraborty, Purushottam</style></author><author><style face="normal" font="default" size="100%">Janet, C. M.</style></author><author><style face="normal" font="default" size="100%">Viswanath, R. P.</style></author><author><style face="normal" font="default" size="100%">Nair, C. Madhavan</style></author><author><style face="normal" font="default" size="100%">Murty, K. V. G. K.</style></author><author><style face="normal" font="default" size="100%">Gopinath, Chinnakonda S.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Electronic structure and catalytic study of solid solution of GaN in ZnO</style></title><secondary-title><style face="normal" font="default" size="100%">Chemistry of Materials</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">JUL</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">13</style></number><publisher><style face="normal" font="default" size="100%">AMER CHEMICAL SOC</style></publisher><pub-location><style face="normal" font="default" size="100%">1155 16TH ST, NW, WASHINGTON, DC 20036 USA</style></pub-location><volume><style face="normal" font="default" size="100%">21</style></volume><pages><style face="normal" font="default" size="100%">2973-2979</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Solid solutions of GaN in ZnO (Zn1-zGaz)(O1-xNx) (x and z &amp;lt;= 0.15) have been prepared by simple solution combustion method, Except for minor changes in the lattice contraction, no significant change in the Wurtzite structure was observed. Raman and secondary ion mass spectrometry results show the direct Zn-N and Ga-N bonds in (Zn1-zGaz)(O1-xNx). Visible light absorption and XPS results demonstrate that N 2p states of nitride occupy the states above the O 2p valence band, and hence a change in optical band gap reduction occurs to similar to 2.5 eV from 3.37 eV for ZnO. Significant nitrogen fixation catalytic activity through NH3 formation has been observed at ambient pressure oil virgin (Zn1-zGaz)(O1-xNx) material, indicating its potential as a catalyst.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">13</style></issue><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">6.397</style></custom4></record></records></xml>