01613nas a2200205   4500008004100000245016200041210006900203260000800272300001200280490000700292520082600299100001901125700002301144700002001167700002801187700002601215700002101241700002101262856012401283       2016                        eng d00aEffects of thermal treatment of ZnO-ZnCr2O4 catalyst on the particle size and product selectivity in dehydrocyclization of crude glycerol and ethylenediamine0 aEffects of thermal treatment of ZnOZnCr2O4 catalyst on the parti  cSEP  a602-6090 v573 aThe ZnO-ZnCr2O4 (Zn-Cr-O) sample obtained by decomposition of Zn-Cr hydrotalcite precursor was subjected to the thermal treatment at different temperatures and the physico-chemical properties of the Zn-Cr-O system were compared with its catalytic behavior in dehydrocyclization of crude glycerol and ethylenediamine (EDA). Upon high temperature treatment of Zn-Cr-O the Cr6+ ions underwent autoreduction to form stable Cr3+ species and the particle size of both ZnO and ZnCr2O4 increased dramatically. Thermal effect did not influence the intermolecular cyclisation of EDA to form pyrazine. By contrast, an inversely proportional dependence was found between the rate of formation of 2-methylpyrazine and the particle size of Zn-Cr-O whereas the rate of 2-pyrazinylmethanol was directly proportional to the particle size.1 aSarkari, Reema1 aKrishna, Vankudoth1 aSudhakar, Medak1 aRao, Tumula, Venkateshw1 aPadmasri, Aytam, Hari1 aSrinivas, Darbha1 aVenugopal, Akula  uhttps://library.ncl.res.in/content/effects-thermal-treatment-zno-zncr2o4-catalyst-particle-size-and-product-selectivity02306nas a2200277   4500008004100000022001400041245013200055210006900187260000800256300001400264490000800278520130000286653002601586653002301612653003001635653002101665653003901686653002701725100002401752700002201776700002801798700002601826700002501852700002401877856012701901       2020                        eng d  a1011-372X00aHighly dispersed MnOx nanoparticles on shape-controlled SiO2 spheres for ecofriendly selective allylic oxidation of cyclohexene0 aHighly dispersed MnOx nanoparticles on shapecontrolled SiO2 sphe  cOCT  a3023-30350 v1503 a<p>Shape-controlled metal nanomaterials are considered as a unique class of catalysts because of their synergistic size- and shape-dependent catalytic properties. This work reports the synthesis of a novel size- and shape-controlled catalyst, consisting of highly dispersed MnOx nanoparticles (average particle size of 4.5 nm) on shape-controlled SiO2 nanospheres (250-300 nm) for selective cyclohexene oxidation using air as the oxidant under solvent- and base-free conditions. The MnOx/SiO2 catalyst exhibited an excellent cyclohexene conversion (92%) with a high selectivity (96%) to the allylic products (2-cyclohexene-ol and 2-cyclohexene-one) under mild conditions, outperforming various SiO2 supported CoOx, FeOx, and CuOx catalysts. The better performance of shape-controlled MnOx/SiO2 nanocatalyst is due to high redox nature of Mn, uniform dispersion of smaller sized MnOx nanoparticles, and synergetic interaction between MnOx and SiO2 spheres, as evidenced by XPS and TEM studies. Further, the MnOx/SiO2 catalyst could be reused at least 5 times for selective cyclohexene oxidation with a negligible loss in its catalytic performance, indicating the excellent stability of shape-controlled metal nanocatalysts in organic synthesis under economically viable and mild conditions.</p>
10aCyclohexene oxidation10aMnOx nanoparticles10aShape-controlled catalyst10aSiO2 nanospheres10aStructure-performance relationship10aSynergetic interaction1 aRao, Bolla, Govinda1 aSudarsanam, Putla1 aRao, Tumula, Venkateshw1 aAmin, Mohamad, Hassan1 aBhargava, Suresh, K.1 aReddy, Benjaram, M.  uhttps://library.ncl.res.in/content/highly-dispersed-mnox-nanoparticles-shape-controlled-sio2-spheres-ecofriendly-selective