IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Applied Surface Analysis Friday Sessions
       Session AS-FrM

Paper AS-FrM3
High-pressure XPS: A New Tool for the In-situ Investigation of Catalysts

Friday, November 2, 2001, 9:00 am, Room 134

Session: Catalysis and Surface Reactivity
Presenter: H. Bluhm, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany
Authors: H. Bluhm, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany
M. Haevecker, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany
A. Knop-Gericke, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany
F. Requejo, Lawrence Berkeley National Laboratory
D.F. Ogletree, Lawrence Berkeley National Laboratory
C.S. Fadley, Lawrence Berkeley National Laboratory
Z. Hussain, Lawrence Berkeley National Laboratory
M. Salmeron, Lawrence Berkeley National Laboratory
R. Schloegl, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany
Correspondent: Click to Email
Photoelectron spectroscopy has been an extremely powerful tool in surface science for decades. It has been extensively used for the ex-situ characterization of catalysts' surfaces. Due to the short mean free path of electrons in a gas phase electron spectroscopies generally must operate in high vacuum. Traditional electron spectrometers are therefore not suited for the much needed characterization of catalytic surfaces under reaction conditions. To overcome these limitations, we have developed a new high-pressure electron spectrometer. Our setup utilizes a differentially pumped electrostatic lens system that refocuses the photoelectrons that are emitted from the sample (which is in a gaseous atmosphere of up to several torr) into the focal plane of a standard electron energy analyzer situated downstream, in the high vacuum region. Using this instrument we have investigated the methanol oxidation over a copper catalyst. The correlation of in-situ XPS spectra of the copper surface and the simultaneously obtained mass spectrometer data (that show the efficiency of the catalytic reaction, i.e. the turnover of the gas phase) allow us to draw conclusions about the electronic state of the catalyst under reaction conditions for the first time.