03004nas a2200265   4500008004100000022001400041245011700055210006900172260006900241300001000310490000800320520201400328653002702342653002102369653001902390653002902409653001902438100002602457700002702483700002402510700002402534700002502558700002402583856013102607       2009                        eng d  a1010-603000aPhysico-chemical, photo-catalytic and O-2-adsorption properties of TiO2 nanotubes coated with gold nanoparticles0 aPhysicochemical photocatalytic and O2adsorption properties of Ti  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcMAR  a24-310 v2033 a<p>Gold-containing titania nanotubes (Au/NT) were found to display higher activity for photooxidation of acetaldehyde, as compared to corresponding gold-free nanotubes and also a Degussa P-25 catalyst. Besides CO2 as a major reaction product, small amounts of H-2, CH4, CO, H2O and CH3COOH were also formed, irrespective of the catalyst employed. High-resolution TEM examination showed that most of the gold particles in Au/NT were of 1.5-5 nm size, distributed both within and at outside surface of the nanotubes. Some larger size (10-70 run) clusters were also seen at the external surfaces, particularly in the samples calcined at an elevated temperature. The temperature-programmed desorption measurements revealed that, compared to P-25 TiO2, a significant entrapment of O-2 occurred at two distinct tubular sites of NT samples, corresponding activation energy of desorption (E,) being around 36 and 41 kcal mol(-1). On the other hand, gold nanoparticles in Au/NT served as independent low-energy (E-a = 26 kcal mol(-1)) sites for adsorption/activation of O-2. These adsorptive properties of TiO2 and Au were lost completely on calcination, thus revealing a crucial role played by the particle size. In situ IR spectroscopy results showed that room-temperature exposure to acetaldehyde + air gave rise to a molecularly bound state, i.e. CH3CHOad, over both NT and Au/NTsamples, which in turn transformed quickly to yield certain acetate (CH3COOad-) and formate (HCOOad-) type transient species with the involvement of the surface OH groups. The decomposition and oxidation of these surface species with the help of O-2(-), O-ad and hydroxyl ion radicals (OH-) formed at photo-excited Au/NT interfaces led to the reaction products mentioned above. We conclude that, besides electron-hole charge separation, the adsorptive properties of host matrix and nanosize gold may together play a significant role in deciding the photo-catalytic properties of Au/TiO2. (C) 2008 Elsevier B.V. All rights reserved.</p>10aAcetaldehyde oxidation10aGold co-catalyst10aO-2-adsorption10aPhoto-catalytic activity10aTiO2 nanotubes1 aMalwadkar, Sachin, S.1 aGholap, Ramkrishna, S.1 aAwate, Shobhana, V.1 aKorake, Prakash, V.1 aChaskar, Manohar, G.1 aGupta, Narendra, M.  uhttps://library.ncl.res.in/content/physico-chemical-photo-catalytic-and-o-2-adsorption-properties-tio2-nanotubes-coated-gold-001721nas a2200241   4500008004100000022001400041245009200055210006900147260007400216300001200290490000800302520090100310653000901211653001201220653001501232653001601247653000701263100002601270700002401296700001801320700002901338856011201367       2012                        eng d  a1878-519000aPreferential oxidation of CO on Ni/CeO2 catalysts in the presence of excess H-2 and CO20 aPreferential oxidation of CO on NiCeO2 catalysts in the presence  aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcDEC  a405-4190 v1073 a<p>Preferential oxidation of CO (CO-PROX) was carried out over Ni supported on CeO2 prepared by the co-precipitation method. The influence of metal loadings (2.5, 5 and 10 wt.% Ni) and the reaction conditions such as reaction temperature and feed composition on CO oxidation and oxidation selectivity were evaluated by using dry reformate gas. No other reactions like CO or CO2 methanation, coking, reverse water gas shift (RWGS) reaction is observed in the temperature range of 100-200 A degrees C on these catalysts. Hydrogen oxidation dominates over CO oxidation above the temperature of 200 A degrees C. An increase in oxygen leads to an increase in CO conversion but a simultaneous decrease in the O-2 selectivity. It has been noticed that 5 and 10 % Ni/CeO2 show better catalytic activity towards CO-PROX reaction. These catalysts were characterized by S-BET, XRD, TEM, XPS and H-2-TPR.</p>10aCeO210aCO-PROX10afuel cells10aMethanation10aNi1 aMalwadkar, Sachin, S.1 aBera, Parthasarathi1 aHegde, M., S.1 aSatyanarayana, C., V. V.  uhttps://library.ncl.res.in/content/preferential-oxidation-co-niceo2-catalysts-presence-excess-h-2-and-co2-0