02702nas a2200337 4500008004100000022001400041245012800055210006900183260007300252300001200325490000700337520156900344653003201913653002601945653001601971653001701987653001402004653001302018653001702031653002302048653001702071653003002088653002002118653000802138100001302146700001502159700001802174700001502192700003002207856012702237 2005 eng d a0926-337300aIn situ XPS investigations of Cu1-xNixZnAl-mixed metal oxide catalysts used in the oxidative steam reforming of bio-ethanol0 aIn situ XPS investigations of Cu1xNixZnAlmixed metal oxide catal aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB a287-2990 v553 a

A series of CuNiZnAl-multicomponent mixed metal oxide catalysts with various Cu/Ni ratios were prepared by the thermal decomposition of Cu1-xNixZnAl-hydrotalcite-like precursors and tested for oxidative steam reforming of bio-ethanol. Dehydrogenation of EtOH to CH3CHO is favored by Cu-rich catalyst. Introduction of Ni leads to C-C bond rupture and producing CO, CO2 and CH4. H-2 yield (selectivity) varied between 2.6-3.0 mol/mol of ethanol converted (50-55%) for all catalysts at 300 degreesC. The above catalysts were subjected to in situ XPS studies to understand the nature of active species involved in the catalytic reaction. Core level and valence band XPS as well as Auger electron spectroscopy revealed the existence of Cu2+, Ni2+ and Zn2+ ions on calcined materials. Upon in situ reduction at reactions temperatures, the Cu2+ was fully reduced to Cu-0. while Ni2+ and Zn2+ were partially reduced to Ni-0 and Zn-0, respectively. On reduction, the nature of ZnO on Cu-rich catalyst changes from crystalline to amorphous, relatively inert and highly stabilized electronically. Relative concentration of the Ni-0 and Zn-0 increases upon reduction with decreasing Cu-content. Valence band results demonstrated that the overlap between 3d bands of Cu and Ni was marginal on calcined materials, and no overlap due to metallic clusters formation after reduction. Nonetheless, the density of states at Fermi level increases dramatically for Ni-rich catalysts and likely this influences the product selectivity. (C) 2004 Elsevier B.V. All rights reserved.

10aauger electron spectroscopy10aAutothermal reforming10aBio-ethanol10acopper oxide10afuel cell10aHydrogen10ahydrotalcite10amixed metal oxides10anickel oxide10aoxidative steam reforming10aSteam reforming10aXPS1 aVelu, S.1 aSuzuki, K.1 aVijayaraj, M.1 aBarman, S.1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/situ-xps-investigations-cu1-xnixznal-mixed-metal-oxide-catalysts-used-oxidative-steam-002717nas a2200301 4500008004100000022001400041245010700055210006900162260007300231300001200304490000800316520171400324653001202038653001802050653002302068653001002091653000702101653001302108653002002121653001802141653002302159100001802182700001602200700002802216700001802244700003002262856012302292 2005 eng d a1381-116900aInsight into the mechanism of selective mono-N-methylation of aniline on Cu1-xZnxFe2O4: a DRIFTS study0 aInsight into the mechanism of selective monoNmethylation of anil aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR a169-1800 v2313 a

Mechanism of selective mono-N-methylation of aniline with methanol on Cu1-xZn2FeO4 catalysts was investigated in detail. The interaction of reactants (aniline. methanol and methanol: aniline) and possible products (N-methylaniline (NMA), N,N-dimethylaniline (DMA) and o-toluidine (OT)) on catalysts surface was studied by temperature-dependent in situ FTIR spectroscopy. Methanol adsorbs dissociatively over catalysts surface at 373 K as methoxy species and is oxidized to formate species at high temperature through dioxymethylene and/or formaldehyde as a surface intermediate species. On the other hand, adsorption of aniline:methanol mixtures shows that methanol oxidation was completely hindered in the presence of aniline. Aniline adsorbs on the Lewis acid sites at <= 373 K with phenyl ring oriented in a perpendicular manner to the catalyst surfaced however, N-H bond scission occurs above 373 K. A comparison of adsorbed NMA and methanol: am line (3:1) mixture on Cu0.5Zn0.5Fe2O4 shows NMA forms from the reaction mixture at 473 K. However, maximum activity at 573 K in catalytic reaction studies suggests that desorption limits the methylation kinetics. FTIR study displays stable aniline and methyl species on ZnFe2O4 even at 573 K; however. no methyl species is detected on Cr0.95Zn0.05Fe2O4 at 473 K due to methanol reforming reaction and that limits the overall reaction and hence low catalytic activity. It is proposed that methanol is protonated on catalysts surface by the labile H+ due to N-H bond scission. Co-adsorption of acidity probes with aniline and methanol indicates that aniline methylation takes place at single acid-base site. (c) 2005 Elsevier B.V. All rights reserved.

10aAniline10aCu1-xZnxFe2O410adesorption limited10aDRIFT10aIR10aMethanol10aN-methylaniline10aN-methylation10areaction mechanism1 aVijayaraj, M.1 aMurugan, B.1 aUmbarkar, Shubhangi, B.1 aHegde, S., G.1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/insight-mechanism-selective-mono-n-methylation-aniline-cu1-xznxfe2o4-drifts-study-001856nas a2200181 4500008004100000022001400041245012200055210006900177260007100246300001600317490000800333520112200341100002401463700002001487700001401507700003001521856012301551 2005 eng d a1520-610600aIsothermal kinetic study of nitric oxide adsorption and decomposition on Pd(111) surfaces: molecular beam experiments0 aIsothermal kinetic study of nitric oxide adsorption and decompos a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUL a13283-132900 v1093 a

The kinetics of NO adsorption and dissociation on Pd(111) surfaces and the NO sticking coefficient (S-NO) were probed by isothermal kinetic measurements between 300 and 525 K using a molecular beam instrument. NO dissociation and N-2 productions were observed in the transient state from 425 K and above on Pd(l 11) surfaces with selective nitrogen production. Maximum nitrogen production was observed between 475 and 500 K. It was found that, at low temperatures, between 300 and 350 K, molecular adsorption occurs with a constant initial SNO of 0.5 until the Pd(I 11) surface is covered to about 70-80% by NO. Then SNO rapidly decreases with further increasing NO coverage, indicating typical precursor kinetics. The dynamic adsorption-desorption equilibrium on Pd(I 11) was probed in modulated beam experiments below 500 K. CO titration experiments after NO dosing indicate the diffusion of oxygen into the subsurface regions and beginning surface oxidation at >= 475 K. Finally, we discuss the results with respect to the rate-limiting character of the different elementary steps of the reaction system.

1 aThirunavukkarasu, K1 aThirumoorthy, K1 aLibuda, X1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/isothermal-kinetic-study-nitric-oxide-adsorption-and-decomposition-pd111-surfaces-002000nas a2200169 4500008004100000022001400041245013100055210006900186260011000255300001600365490000700381520124000388100002501628700001701653700003001670856013001700 2014 eng d a1477-922600aIn1-XGaXN@ZnO: a rationally designed and quantum dot integrated material for water splitting and solar harvesting applications0 aIn1XGaXNZnO a rationally designed and quantum dot integrated mat aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP a12546-125540 v433 a

The highly desirable combination of the visible light absorption properties of In1-xGaxN Quantum dots (QD) along with the multifunctionality of ZnO into a single integrated material was prepared for solar harvesting. This is the first report on InGaN QD integrated with ZnO (InGaN@ZnO), synthesized by a highly reproducible, simple combustion method in 15 min. Structural, microstructural and electronic integration of the nitride and oxide components of InGaN@ZnO was demonstrated by appropriate characterization methods. Self-assembly of InGaN QD is induced in growing nascent zinc oxo nanoclusters taking advantage of the common wurtzite structure and nitrogen incorporation at the expense of oxygen vacancies. Direct integration brings about a single phase structure exhibiting extensive visible tight absorption and high photostability. InGaN@ZnO suggests synergistic operation of tight harvesting and charge conducting components for solar H-2 generation without using any co-catalyst or sacrificial agent, and a promising photocurrent generation at 0 V under visible light illumination. The present study suggests a direct integration of QD with the host matrix and is a potential method to realize the advantages of QDs.

1 aRajaambal, Sivaraman1 aMapa, Maitri1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/in1-xgaxnzno-rationally-designed-and-quantum-dot-integrated-material-water-splitting-and-002045nas a2200337 4500008004100000022001400041245014400055210006900199260000900268300001100277490000800288520095100296653001401247653001401261653001901275653000901294653001601303100002101319700001801340700001701358700002301375700002601398700002401424700002101448700001701469700002001486700003001506700002301536700001701559856013101576 2021 eng d a0926-860X00aIn-situ experimental and computational approach to investigate the nature of active site in low-temperature CO-PROX over CuOx-CeO2 catalyst0 aInsitu experimental and computational approach to investigate th cAUG  a1183050 v6243 aPreferential oxidation (PROX) of carbon monoxide (CO) in presence of excess hydrogen is a necessity to prevent poisoning of the Pt-anode by CO in PEMFCs (Polymer Electrolyte Membrane Fuel Cell). A highly active catalyst, 5 wt% Cu-CeO2 showed 100 % CO conversion at 65 degrees C without any undesirable oxidation of H-2. The catalyst showed no deactivation even after 100 h on stream, making it viable for practical fuel cell application. Operando EPR in the PROX reaction condition revealed highly dispersed mixed valent cations with oxygen vacancies, responsible for the low-temperature PROX activity. At the active site, both Cu and Ce ions were shown to reversibly change their valence states to facilitate the abstraction of bridging lattice oxygen for CO oxidation to CO2. This surface oxygen mediated CO oxidation was found to be much faster than that of H-2 to H2O, which could explain the complete selectivity of oxygen for CO2 formation.10aCuOx-CeO210ainterface10aOxygen vacancy10aPROX10aSynergistic1 aAdak, Shubhadeep1 aRabeah, Jabor1 aRanjan, Ravi1 aKhan, Tuhin, Suvra1 aPoddar, Mukesh, Kumar1 aGupta, Rishi, Kumar1 aSasaki, Takehiko1 aKumar, Sagar1 aBordoloi, Ankur1 aGopinath, Chinnakonda, S.1 aBruckner, Angelika1 aBal, Rajaram uhttps://library.ncl.res.in/content/situ-experimental-and-computational-approach-investigate-nature-active-site-low-temperature