20_Exposes UJF-UTA by lanyuehua

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									     Surface Science Studies
            of Catalytic Surfaces
        in Realistic Conditions
                                  F.J. Cadete Santos Aires
IRCELYON - Institut de Recherches sur la Catalyse et L’Environnement de Lyon
                           (UMR 5256 CNRS/Université Lyon 1)
         2, Avenue Albert Einstein. 69626 – Villeurbanne cedex. France.

                                                                               francisco.aires@ircelyon.univ-lyon1.fr
           "Workshop on Nanosciences & Nanotechnology: From Smart Materials to Devices"
    A meeting between the University Joseph Fourier of Grenoble and the University of Texas at Austin
                                    Autrans, October 2009, 11th-13th
                              Catalysis
« The substances that cause the decomposition of H2O2 do not achieve this
goal by being incorporated into the new compounds (H2O and O2); in each
case they remain unchanged and hence act by means of an inherent force
whose nature is still unknown... So long as the nature of the new force
remains hidden, it will help our researches and discussions about it if we
have a special name for it. I hence will name it the catalytic force of the
substances, and I will name decomposition by this force catalysis.
The catalytic force is reflected in the capacity that some substances have,
by their mere presence and not by their own reactivity, to awaken activities
that are slumbering in molecules at a given temperature. »



                                                           J.J. Berzelius
                in the Edinburgh New Philosophical Journal XXI (1836) 223
                                            Catalyst




   Adsorption and (possible) consequent
                                                             High surface-volume ratio
     dissociation occurs at the surface
                                                                       Economy of atoms
                                                                       Specific sites
                                                                       Specific electronic properties
                                            Catalytic site

 Static active site :                                                  Dynamic active site
    low-coordination surface atom                                                           G. Ertl
                                                                     Faraday Discuss. 121 (2002) 1
H.S. Taylor
Proc. Roy. Soc. (London) A 108 (1925) 105                                  G.A. Somorjai, A.L. Marsh
                                                             Philos. Trans. R. Soc. A 363 (2005) 879
                              Catalyst
                                           [0 1 1]

                                                                          (1 0 0)
                   Pd


α-Si3N4                                                               (-1 1 -1)
                        PdO              (-1 -1 1)

                                         counts
                                                                          Pd81Au19
                                                             Pd
                                                     Au



  Supported catalyst
                                                          Energy ( keV)


                                                  Alloy nanoparticle
                                                    Catalyst




                                       600 nm x 600 nm
         Surfaces                      Nanostructured surfaces                Supported catalysts

                                       Arrays of nanoparticles


Surface émaillée        Surface avec
« standard »            revêtement
                        catalytique


Salissures




CALOR-SEB « autoclean catalys »            Sunkiss : radiant panel
                                           F.J. Cadete Santos Aires et al.     Shaped catalysts (C. Geantet)
Patent : FR 2 825 385
                                           Applied Catalysis 238 (2003) 289
J.C. Bertolini et al

     Catalyst on flat surface           Washcoated supported catalysts        Compacted supported catalysts
        Institut de Recherches sur la Catalyse et l’Environnement de Lyon

                                          Director:           Michel Lacroix
                                          Deputy director: Jean-Marie Herrmann

Laboratory Council                                                                               Head of administration
                                           Scientific Council        Communication
                                                                     Security
                                                                     Quality
Scientific and technical          Computer Dpt
      department
                                                                                                    Administration
                                                             Research Teams

                                                       Clean and Renewable Energies                  Secretary
Analysis         Infrastructure                               A. Auroux & P. Gélin                   Comptability
TGA - DTA        Electricity
                                                  Engineering & Process Intensification              Reception
CPG-SM           Electronics                            C. Mirodatos & Y. Schuurman                  Missions
X-Ray            Mechanics
                                                 Functionnal & Nanostructured Materials
XPS-LEISS        Prototype                                S. Daniele & J.L. Rousset
IR-UV Vis        Shop
NMR sol                                    Refining & Innovative Valorisations of Hydrocarbons
                                                           C. Geantet & J. M. Millet
NMR liq
Raman                                      Air cleaning, Gas treatment, Atmospheric chemistry
                                                            C.George & P. Vernoux
E-Microscopy
                                                      Water and Waste Water Treatment
                                                             C. Guillard & M. Besson
                                            Valorisation of bioressources & Green Chemistry
                                                            N. Essayem & C. Pinel

                                                           Surfaces & Interfaces
                                                      F. Cadete Santos Aires & F. Gaillard
                                SURFACES & INTERFACES
                                                Philosophy
Surface characterization metals and alloys (single- & poly- crystalline surfaces)
Proprieties : adsorption, reactivity, reconstruction, segregation
UHV (<10-9 mbar): XPS, LEISS, AES, LEED, HREELS, TPD, UPS
Gas pressure (10–8 mbar to Patm) : DRIFTS, ATR, PM-IRRAS, STM (+AFM), SXRD, XPS
+ reactor


                                    CO




                                                        Elaboration, characterization and
                                                 catalytic performances of model/real catalysts
                                                   (supported nanoparticles, self-assembled systems)
                                 Elaboration of metal catalysts (chemical methods, laser ablation, evaporation)
                                 Local characterization : HRTEM, HAADF, EDX, ESEM, AFM…
                                 ITPD, microkinetics
                                 elotrocatalytic thin films




                                Towards real catalysts (supported metals) and applications
                                       Development of specific tools and methodology
                                SURFACES & INTERFACES
                                                Philosophy
Surface characterization metals and alloys (single- & poly- crystalline surfaces)
Proprieties : adsorption, reactivity, reconstruction, segregation
UHV (<10-9 mbar): XPS, LEISS, AES, LEED, HREELS, TPD, UPS
Gas pressure (10–8 mbar to Patm) : DRIFTS, ATR, PM-IRRAS, STM (+AFM), SXRD, XPS
+ reactor


  Pd-Ni for nanotube synthesis (ANR ECLAT, 2007 – 2010) - model & supported catalysts


  Pd-Sn and Pt-Sn for 1,3-Butadiene hydrogenation (K. Pattamakomsan, ongoing) - surfaces &
                                                                    supported catalysts


  Pt-Sn for CO Oxidation (C. Dupont, PhD, 2008) – surfaces


  Au-Ag for CO Oxidation – surfaces & supported catalysts


  Pd-Au for CO Oxidation (M.A. Languille, PhD, 2008) - surfaces
         Supported Au is an excellent catalyst
        for the CO oxidation at low temperature
                            Haruta et al., J. Catal. 301, 299 (1989)


► role of the support - O2 dissociation/”mobility”
► size effects (Meier & Goodman, JACS 126, 1892 (2004))
► specific sites (in extended surfaces)


          Surface science approach : Au surfaces
          Single crystal surfaces with different sites

            Au(111)   N=9                  Au(110)    N=7




            Compact surface                  Open surface
                                  CO adsorption on Au(110) & Au (111)
                                                                                                                                  Au(111)-22x√3        compact surface
 open surface
                                                                                               « herringbone » reconstruction
                   [1 -1 0 ]


                                                                           0.16           CO/Au
                                                                                           300 K
                                                                                                                                                             1000 x 1000 nm2
                                         C-O vibration band area [u. a.]


                                                                           0.12
   1000 x 1000 nm2
                                                                                                      Surf. Sci. 521, 639 (2002)
                        0.816 nm
                                                                           0.08                          Au(110)
[1 -1 0 ]
                                                                           0.04
                                                                                                                      Au(111)
                                                                                                      Surf. Sci. 566-568, 995 (2004)
                                                                           0.00
                                                                                  0.001        0.01        0.1                1        10        100

                                                                                                         CO pressure [Torr]                                   150 x 150 nm2
<1 1 0> <1 -1 0>                                                                                                                                             hcp : ABABAB…
                                     Surface Science                                                                                       Surface Science
                                     521 (2002) L639                                                                                    566-568 (2004) 995

                               <0 0 1>   Au(110)-1x2
                                         Missing row reconstruction                                                                                           fcc : ABCABC…
       Au particles with (110) & (111) exposed faces

                             L.D. Marks et al.
                             Surface Science 139 (1984) 281
                             Surface Science 143 (1984) 495
                             Ultramicroscopy 16 (1985) 101
                             Surface Science 157 (1985) L367




           Au(110)                           Au(111)




                             « defect » separating an fcc (ABC) region
Missing-row reconstruction           from an hcp (ABA) region
               Follow the behaviour of the surface during reaction → in situ experiments


                                            Adsorbed species
                                                                                            Heating/cooling
                                                                                                braids



                                                                                                         sample
                                                                                                            tip
                                            Local structure                                        Piezo-tube
Jugnet et al., Catal. Lett. 56, 17 (1998)


                                            « Average » structure
                                                                                                                      Micro LH (Omicron) modified

                                                                                                     Cadete Santos Aires et al.,
                                                                                                     Proc.12th European Congress on
                                                                                                     Electron Microscopy Vol. III, 263 (2000)

                                                                                    Sample with Z
                                                                                    displacement +        Environmental cell

                                            Chemical state                          heating resistance




  Gonio head
                  Detection
                  window
                                                                              L
Saint-Lager et al.,                                                       LEI
                                                                     r SO         15° incident X-rays through
Rev. Sci. Instrum. 78, 20839021 (2007)                          S fo              a 100nm-Al window
                                                             XP          S                                                     Independently pumped
                                                          HP          RE                                                       analyzer optics
                                                                  AP 12)
                                                              RS                     Ogletree et al., Rev. Sci. Instrum. 73, 3872 (2002)
                                                           AN 9 – 20
                                                               0
                                                            (20
    P : 10-9 Torr
                           PCO : 0.01 Torr     PCO : 0.1 Torr
 <1 -1 0>
     (1x2)                                        [1-10]                CO/Au(110) by in situ STM
           2                       [1-10]
          m
       9n                                                 [001]
    9x
                                                                        PCO : 0.5 Torr      PCO : 1 Torr
                                              1.6nm


   350 x 350 nm2            60 x 60 nm2        60 x 60 nm2
(1x2) reconstructed        Slow deconstruction of the
    surface with               surface structure
 monoatomic steps
                                                                       350 x 350 nm2       350 x 350 nm2

                                                                             New morphology of the surface
            [001]        Increasing CO pressure                                with atomic-high islands

                                                                                         PCO : 30 Torr

                                                      PCO : 120 Torr         (1x1)
                       PCO : 500 Torr
                              <1 -1 0>
                                     c(4x4)                               25x25nm2


                               25 x 25 nm2
                                                                                         350 x 350 nm2

  New surface
                                                      350 x 350 nm2
structure c(4x4)
                      350 x 350 nm2              Unreconstructed surface( 1x1)
      P : 10-9 Torr
                           PCO : 0.01 Torr     PCO : 0.1 Torr
  <1 -1 0>
       (1x2)                                      [1-10]                CO/Au(110) by in situ STM
             2                     [1-10]
            m
         9n                                               [001]
      9x
                                                                        PCO : 0.5 Torr      PCO : 1 Torr
                                              1.6nm


   350 x 350 nm2            60 x 60 nm2        60 x 60 nm2
(1x2) reconstructed        Slow deconstruction of the
    surface with               surface structure
 monoatomic steps
                                                                       350 x 350 nm2       350 x 350 nm2
PO2 : 500 Torr
                        add an element to Au
                                                                             New morphology of the surface
                      capable of O2 dissociation                               with atomic-high islands
             [001]
   0.82 nm
                                                                                         PCO : 30 Torr
                            Pd70Au30(110)
                                                      PCO : 120 Torr         (1x1)
                       PCO : 500 Torr
                              <1 -1 0>
                                     c(4x4)                               25x25nm2


                               25 x 25 nm2
                                                                                         350 x 350 nm2

   New surface
                                                      350 x 350 nm2
 structure c(4x4)
                      350 x 350 nm2              Unreconstructed surface( 1x1)
                               Pd70Au30(110)
                                                               [1 -1 0 ]




     400 x 400 nm2               100 x 100 nm2            20 x 20 nm2


                                          [001]                 Before annealing




                      0.3nm    0.4nm
                                                                After annealing

                                                                                      Au
                                                                                   migration




LEED pattern,
primary electron                                  LEISS
energy 130eV         4.7x3 nm2, -80mV, 5nA
                   CO adsorption on Pd70Au30(110)




                                          linear CO / Pd
                         linear CO / Au




                                                           bridged CO
                                                                        PM-IRRAS

Intensity [u.a.]




                                          Wavenumber [cm-1]
                 CO adsorption on Pd70Au30(110)                           1 Torr, Tamb




             SXRD   Conservation of the anisotropy of the terraces
                             «rice grain» structure : domain size ~4 nm

     UHV
                           on grains, pseudo‐periodicity ~0.4‐0.5 nm
                                           corrugation ~0.05‐0.06 nm
P(CO) = 1 Torr
Intensity [u.a.]        CO adsorption on Pd70Au30(110)




                    Binding energy [eV]

                   Pd segregation
                                                Binding energy [eV]
morphology       structure      sites                sites                              structure    morphology
                        &                                                               pseudo
   Terrace                                                                             periodicity
 anisotropy
disappears +
   islands




                                 Linear CO / Au
                                                                                                     Roughness
                                                                                                         on




                                                                    Linear CO / Pd
                                                  Linear CO Au
                                                  Linear CO // Au
                                                                                                      terraces




                                                                                     Bridged CO
   Island
 percolation




               deconstruction

 Terraces +
alignements
O2 adsorption on Pd70Au30(110)
                                 500 Torr, Tamb
O2 adsorption on Pd70Au30(110)
 Variable hν

                                      vacuum




                Kinetic energy [eV]

               Pd segregation
  O2 adsorption on Pd70Au30(110)
                                                                     300 K
Au 4f7/2       hν = 340 eV           Pd 3d3/2          hν = 600 eV




                  30 min after
                  p(O2)=0.5 Torr




                 10 min after
                 p(O2)=0.5 Torr


                           just after
                           p(O2)=0.5 Torr
                     Clean surface



    Binding energy [eV]                     Binding energy [eV]


       Formation of nanodomains on the surface
             O2 adsorption on Pd70Au30(110)




UHV

                                                1 Torr, 673 K
      Binding energy [eV]

                                       Binding energy [eV]
        O2 adsorption on Pd70Au30(110)
                                                 1 Torr, 673 K




Binding energy [eV]        Kinetic energy [eV]
                         Binding energy [eV]
                            Surface oxide
                                          O2 adsorption on Pd70Au30(110)
Oxygen induced reconstruction, segregation and thin layer oxide
                                                                                                    Au69eV
                                                                                               r=           ~0
                                                                                                    Pd330eV
                            10
                                 3                      oxide
                                                         oxyde   Sharp peak
                                                                         oxide
                                               (2x2)STM Pd (0 1,475 0) oxyde
                            10
                                 1
                                                        no surface p      Pd
                                                                     eak
       O2 pressure (mbar)




                                 -1
                            10                       (1x2)
                                                     PdAu
                                 -3
                            10
                                                                   (0 1,52 0)
                                 -5                               Broad peak
                            10                                                                Pd segregation
                                 -7                                             (1x2)
                            10                    (1x1)                         PdAu
                                 -9
                                                   Au
                            10
                                      0            50
                                                  300            100
                                                                 350       150
                                                                           400          200
                                                                                        450
                                                    sample temperature (K)
                                                                                                   Au69eV
                            Au69eV                                                            r=          = 2,4
                                               Au69eV                                              Pd330eV
                                          r=          = 4,2
                                               Pd330eV


                                                 Pd330eV
morphology     structure   structure     morphology

                                          Roughness
                                              on
                                           terraces

                                         Oxide growth




                           Sub-surface
  Terraces +                 oxide ?
 alignements




                           (1x1)
                                     CO+O2 on Pd70Au30(110)



                                PdAu(110)




                                                                                        Increasing time
                             k scan along (0 k 0.05)
    Intensité [u.a.]
Intensity [u.a.]




                                                                                       temps


                                                                                     P(O2) = @T=473K
                                                                                   p(O2)=500Torr500 Torr@473K

                                                                                   p(CO)=1Torr @T=273K
                                                                                     P(CO) = 1 Torr       @ 273 K



                       0.9     1.0   1.1   1.2   1.3     1.4   1.5   1.6   1.7   1.8
                                                  k [u.r.r.]
                                                     k
                      CO + O2 sur Pd70Au30(110)

                                                   Pd 3d3/2

                     473 K




Continuous                                                    p(CO)=0.05 Torr
introduction of CO
                                                              p(O2)=0.5 Torr
                                                              p(CO)=0.1 Torr
Short introduction
of CO                                                         p(O2)=0.5 Torr


                             Binding energy [eV]
                                CO+O2 on Pd70Au30(110)
473K                      +0,15 Torr CO                       +0,5 Torr CO
very large excess                                                              ratio:
                                                                              0.95
of oxygen                                                                      signal CO2
                                               CO                               signalCO
                                                                              0.9


                                                                              0.85




                           500 Torr
                              O2
                                          PCO2/PCO                            0.8
           partial
         pressure                                                             0.75

             (a.u.)                             CO2                           0.7


                                                                              0.65
                      0               1                   2               3
                                      Time(hours)                                           No Au
                           oxide          metal       oxide       metal                  Pd surface
            height                                                                   after CO reduction
            of the
       diffraction
              peak
             from
       oxide layer

                      0               1                   2               3
                                          Time ( hours)
                              Conclusion
Pd70Au30(110) UHV              outmost atomic plan [Au] > 80 %
                               (1x1)


               CO              roughnening of the surface
                               Pd segregation


               O2              (2xn) n=2, 3
                               strong Pd segregation
                               PdO grows on an organized surface (high p(O2))


               CO+O2           occurs on a PdO surface layer

  Surface is continuously evolving.
  Observation of new surface structures.
                in situ experiments are essential
                            Aknowledgements
    Marie-Angélique Languille (now at IPANEMA Platform at SOLEIL)
    Yvette Jugnet, Eric Ehret, Pierre Delichère, Jean-Claude Bertolini (emeritus)


      Advanced Light Source (ALS)
                                                  European Synchrotron
   Lawrence Berkeley National Laboratory         Radiation Facility (ESRF)
         (LNBL) (Berkeley, USA)
                                      XPS             (Grenoble, France)     SXRD




Simon Mun
                                            Marie-Claire Saint-Lager (Institut Néel)
(also at Hanyang University, Korea)
Hendrik Bluhm, Miquel Salmeron

								
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