@article { ISI:000245961800014, title = {Reduction of oxygen by hydroxylammonium salt or hydroxylamine over supported Au nanoparticles for in situ generation of hydrogen peroxide in aqueous or non-aqueous medium}, journal = {Catalysis Communications}, volume = {8}, number = {5}, year = {2007}, month = {MAY}, pages = {811-816}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Reaction of O-2 with hydroxylamine or its salts over a number of supported gold catalysts containing An nanoparticles (at 10-70 degrees C) has been studied at atmospheric pressure for the in situ generation of H2O2 (required for organic oxidation reactions in the synthesis of fine/specialty chemicals) in aqueous (water) or non-aqueous medium. Hydrogen peroxide in high yields with harmless by-products (viz. water and nitrogen) can be generated in situ by the reduction Of O-2 by hydroxylammonium sulfate (or chloride) or hydroxylamine using the supported gold catalysts particularly Au/Gd2O3, Au/La2O3 and Au/MgO, in aqueous (water) or non-aqueous (viz. methanol) medium at close to ambient conditions. The reduction of O-2 by hydroxylammonium salt to H2O2, however, requires preneutralization of the salt by alkali; in the absence of the neutralization, only water is formed in the reaction. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Au Nanoparticles, Au/Gd2O3, Au/La2O3, Au/MgO, Hydrogen peroxide, hydroxylamine, hydroxylammonium salts, in situ H2O2 generation}, issn = {1566-7367}, doi = {10.1016/j.catcom.2006.08.041}, author = {Choudhary, Vasant R. and Jana, Prabhas and Bhargava, Suresh Kumar} } @article { ISI:000286307300007, title = {Synthesis of Sb-doped SnO2 nanowires and hyperbranched structures}, journal = {Science of Advanced Materials}, volume = {1}, number = {1}, year = {2009}, month = {APR}, pages = {38-43}, publisher = {AMER SCIENTIFIC PUBLISHERS}, address = {26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA}, abstract = {

Branched nanostructures of semiconducting materials are of great interest for their potential applications in optoelectronic, photonic devices and sensors. We herein describe a facile single-step chemical vapor deposition route for the synthesis of Sb-SnO2 hyperbranched nanostructures comprised of elongated nanowires with 30-40 nm diameter and 10-20 Am length. The morphology and structure has been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), selective area electron diffraction (SAED), and powder X-ray diffraction (XRD). Also, a possible mechanism is proposed for the growth of nanowires into the hyperbranched form on the basis of the substrate effect, the role of Au nanoparticles, and the effect of Sb doping on specific morphology evolution. Interestingly, electrical conductivity measurements as a function of temperature suggest a semiconducting behavior, despite being governed by different electron-transport mechanisms with activation energies of 0.55 and 0.17 eV, which correspond to pure SnO2 and Sb-SnO2 nanowires, respectively. A precise control over the operating parameters not only envisages custom-designed, branched structures by a simple and economical route but also offers an alternative method to the expensive and tedious nanofabrication techniques for industrial applications.

}, keywords = {Au Nanoparticles, chemical vapor deposition, Sb-SnO2 Hyperbranched Nanostructures}, issn = {1947-2935}, doi = {10.1166/sam.2009.1006}, author = {Sathe, Bhaskar R. and Patil, Mrudula and Walke, Pravin S. and Vivek, J. P. and Lele, Ashish K. and Pillai, Vijayamohanan K. and Mulla, Imtiaz S.} } @article { ISI:000381593700007, title = {Spectroscopy and catalytic activity study of gold supported on barium titanate nanotubes for styrene epoxidation}, journal = {Applied Catalysis A-General}, volume = {523}, year = {2016}, month = {AUG}, pages = {61-72}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Gold (0.5-5 wt.\%) supported on barium titanate nanotubes (Au/BaTNT) were prepared, characterized and for the first time, investigated as catalysts for selective oxidation of styrene with oxygen (O-2 or H-2 + O-2) and peroxides (H2O2 or TBHP). Conversion of styrene enhanced when H-2 was co-added to O-2 in the reactions. Au/BaTNT activated O-2 and H-2 and produced H2O2 in situ for use in oxidations. Peroxides were found better oxidants than O-2. At optimized conditions, styrene oxide selectivity of 80.1 wt.\% at styrene conversion of 60.5 wt.\% was achieved over Au(1 wt.\%)/BaTNT using TBHP. Au particles (5.0-7.4 nm) were dispersed and decorated on the walls of BaTNT. They exhibited superior performance to the known Au catalysts in styrene oxidation. Reactive oxygen species formed during oxidation reactions were followed with in situ spectral characterizations (diffuse reflectance UV-vis and FT -Raman). Au/BaTNT was reusable in four recycles with little loss in catalytic activity. (C) 2016 Elsevier B.V. All rights reserved.

}, keywords = {Au Nanoparticles, reactive oxygen species, spectroscopy, Styrene Oxidation, Titanate nanotubes}, issn = {0926-860X}, doi = {10.1016/j.apcata.2016.05.014}, author = {Nepak, Devadutta and Srinivas, Darbha} } @article {47686, title = {Active and recyclable gold metal nanoparticles catalyst supported on nitrogen-doped mesoporous carbon for chemoselective hydrogenation of cinnamaldehyde to cinnamyl alcohol}, journal = {Chemistry-An Asian Journal}, volume = {16}, year = {2021}, month = {SEP }, pages = {2702-2722}, type = {Article}, abstract = {Several supported gold metal catalysts with different Au nanoparticles sizes were prepared and evaluated for the chemoselective hydrogenation of cinnamaldehyde (CA) to cinnamyl alcohol (CAL). To investigate the structure-activity relationship, stability of catalyst, heterogeneity and recyclability, the structural characteristics of materials and Au catalysts (fresh and spent catalysts) were studied by employing variety of physico-chemical techniques. The interrelationship among Au nanoparticles size (nm) with turnover frequency (h(-1)) of Au catalysts has also been explored. Among the various Au catalysts tested, nitrogen-doped mesoporous carbon (NMC) supported Au catalyst having homogeneously dispersed (78.8\%) Au nanoparticles (1.6 nm) synthesized by sol-immobilization method (Au-NMC-SI) demonstrated improved catalytic activity affording 78\% CAL selectivity and 94.2\% CA conversion without using any promoter. Moreover, Au-NMC-SI catalyst exhibited good recyclability and stability. The catalyst synthesis approach described in this investigation opens up a novel strategy for the design of highly efficient metal nano-catalysts supported on NMC materials.}, keywords = {Au Nanoparticles, heterogeneous catalysis, Hydrogenation, Nitrogen-doped mesoporous carbon, Support-Metal interaction}, issn = {1861-4728}, doi = {10.1002/asia.202100552}, author = {Nagpure, Atul S. and Gogoi, Pranjal and Chilukuri, Satyanarayana V.} }