01987nas a2200229 4500008004100000022001400041245013900055210006900194260006100263300001000324490000800334520112700342653002001469653001401489653001301503653001901516653001701535653001201552100003201564700003001596856013101626 2007 eng d a1011-372X00aFabrication of an effusive molecular beam instrument for surface reaction kinetics - CO oxidation and NO reduction on Pd(111) surfaces0 aFabrication of an effusive molecular beam instrument for surface a233 SPRING STREET, NEW YORK, NY 10013 USAbSPRINGERcNOV a50-580 v1193 a

A simple molecular beam instrument (MBI) was fabricated for measuring the fundamental parameters in catalysis such as, sticking coefficient, transient and steady state kinetics and reaction mechanism of gas/vapor phase reactions on metal surfaces. Important aspects of MBI fabrication are given in detail. Nitric oxide (NO) decomposition and NO reduction with carbon monoxide (CO) on Pd(111) surfaces were studied. Interesting results were observed for the above reactions and they support the efficiency of the MBI to derive the fundamental parameters of adsorption and catalysis. Sustenance of CO oxidation at 400 K is dependent mostly on the absence of CO-poisoning; apparently, CO + O recombination is the rate determining step <= 400 K. NO adsorption measurements on Pd(111) surface clearly indicating a typical precursor kinetics. Displacement of the chemisorbed CO by NO on Pd(111) surfaces was observed directly with NO + CO beams in the transient kinetics. It is also relatively easy to identify the rate-determining step directly from the MBI data and the same was demonstrated for the above reactions.

10acarbon monoxide10acatalysis10akinetics10amolecular beam10anitric oxide10aPd(111)1 aThirunavukkarasu, Kandasamy1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/fabrication-effusive-molecular-beam-instrument-surface-reaction-kinetics-co-oxidation-and-001985nas a2200253 4500008004100000022001400041245010300055210006900158260007700227300001400304490000600318520106600324653002001390653000901410653002801419653001401447653001001461100002601471700002901497700002601526700002601552700003001578856012301608 2014 eng d a1867-388000aRole of nanointerfaces in Cu- and Cu plus Au-based near-ambient-temperature CO oxidation catalysts0 aRole of nanointerfaces in Cu and Cu plus Aubased nearambienttemp aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcNOV a3116-31240 v63 a

Disordered mesoporous Cu-doped ceria-zirconia (Cu0.1Ce0.85Zr0.05O2), and gold deposited (Au/Cu0.1Ce0.85Zr0.05O2) catalysts were synthesized and evaluated for CO oxidation. Onset of CO oxidation activity, and 50% (100%) CO2 formation occurs at room temperature (RT), and 77 (120)degrees C, respectively, with Cu0.1Ce0.85Zr0.05O2. A small amount of gold on Cu0.1Ce0.85Zr0.05O2 induces the sustainable oxidation catalysis around RT. Onset of copper reduction temperature decreases from 110 degrees C on Cu0.1Ce0.85Zr0.05O2 to 48 degrees C with Au/Cu0.1Ce0.85Zr0.05O2, highlighting the direct interaction between Cu and Au through a Cu-Au interface. Au particles with a (00 1) facet deposit on an oxygen-deficient site of (111) facet of CeO2-ZrO2. Any decrease in surface Cu-content with increasing Au-content further supports the Au-Cu-Ce/Zr interface interactions. Nanointerfaces of Au clusters on Cu next to oxygen-deficient sites of CeO2-ZrO2 facilitate all the elementary steps of the CO + O-2 reaction to occur in close proximity at ambient conditions.

10acarbon monoxide10aGold10aheterogeneous catalysis10aOxidation10aredox1 aGnanakumar, Edwin, S.1 aNaik, Jarpla, Madhusudha1 aManikandan, Marimuthu1 aRaja, Thirumalaiswamy1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/role-nanointerfaces-cu-and-cu-plus-au-based-near-ambient-temperature-co-oxidation-002884nas a2200301 4500008004100000022001400041245016300055210006900218260000800287300001800295490000800313520181300321653002402134653002002158653001402178653001702192653001202209653002902221653001902250653002802269653003602297653001502333100001602348700002902364700002702393700003002420856013202450 2017 eng d a1932-744700aWater mediated deactivation of Co3O4 naonrods catalyst for CO oxidation and resumption of activity at and above 373 K: electronic structural aspects by NAPPES0 aWater mediated deactivation of Co3O4 naonrods catalyst for CO ox cSEP a20296–203050 v1213 a

The catalytic activity of the Co3O4 nanorods (NRs) for the CO oxidation reaction and the effect of water on the catalytic reaction have been explored with near-ambient pressure photoelectron spectroscopy (NAPPES) and mass spectral analysis. Comparative NAPPES studies have been employed to understand the elucidation of the catalytic reaction pathway and the evolution of various surface species. The results confirm the suppression of the CO oxidation activity on the Co3O4 NRs in the presence of water vapor. Various type of surface species, such as CO(ads), hydroxyl, carbonate, formate, are found to be present on the catalyst surface depending on the reaction conditions. Vibrational features of CO, O-2, and CO, were observed and shift in binding energy of these features under the reaction conditions directly suggests a change in work function of the catalyst surface. Under dry conditions, CO couples with labile 0 atoms to form CO2; however, under wet conditions, CO predominantly interacts with surface OH groups resulting in the formation of carbonate and formate intermediates. In situ studies of oxidation of CO on Co3O4 shows that CO oxidation depends not only on surface Co3+ concentration but also influenced by Co-3/Co' ratio on the catalyst surface. The carbonate was found to be a reaction inhibitor at room temperature; however, it acts as an active intermediate at 375 K and above. Above the boiling point of water, Co3O4 NR surfaces begin to show the oxidation activity even in the presence of water vapor. The intrinsic role of intermediate species was used to derive a possible reaction mechanism under different reaction conditions.

10aAmbinent-temprature10acarbon monoxide10aGas Shift10aH Activation10aIn-situ10aLow-temprature oxidation10aMolecular-beam10aPerformance enhancement10aRay Photoelectron-Spectroscopyu10aThin-films1 aJain, Ruchi1 aReddy, Kasala, Prabhakar1 aGhosalya, Manoj, Kumar1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/water-mediated-deactivation-co3o4-naonrods-catalyst-co-oxidation-and-resumption-activity-and