ISISS station

Innovative Station for In Situ Spectroscopy

The scientific aim at ISISS is to study the electronic surface/near surface structure of functional materials in the presence of a reactive environment. This includes both gas/solid interfaces (e.g. heterogeneous catalysis) and liquid/solid interfaces (e.g. catalytic water splitting).

Selected Applications:
  • X-ray photoelectron spectroscopy (XPS) under high vacuum (p=10^(-12) mbar) and near ambient pressure conditions (typically 1 mbar)
  • X-ray aborption spectroscopy (XAS) at pressure up to 10 mbar with NAP-HE-XPS endstation
Fig. 1: picture of NAP-HE-XPS (courtesy of SPECS GmbH, Berlin) <br><br><br>

Fig. 1: picture of NAP-HE-XPS (courtesy of SPECS GmbH, Berlin)



Methods

Time-resolved absorption, NEXAFS, Mass Spectrometry, XPS, NAP-XPS

Remote access

depends on experiment - please discuss with Instrument Scientist

Beamline data
Energy range 80 - 2000 eV
Energy resolution >15,000 at 400eV
Flux 6x1e10 photons/s/0.1A with 111µm exit slit
Polarisation linear horizontal
Focus size (hor. x vert.) 100x80 µm2
Phone +49 30 8062 14905 / 14906
More details ISISS
Station data
NAP-HE-XPS
Temperature range room temperature up to 1000 K
Pressure range Maximum pressure: 20 mbar
Minimum pressure: 10-12 mbar
Typical pressure: 1 mbar

For more details contact the instrument scientist.
Detector 2D delay line detector (2D DLD) (SURFACE CONCEPT, Mainz)
Manipulators various, exchangeable with optimised for sample environments
Sample holder compatibility Homemade concept. Check text below. For more details contact the station manager.
Additional equipment
gas analytics
  • electron impact mass spectrometer (differentially pumped)
  • proton-transfer-reaction mass spectrometer (PTR-MS)
  • gas chromatograph
Fig. 2: Scheme of the NAP-HE-XPS endstation installed at the ISISS beamline.<br> The spectrometer (right site) is displayed retracted from the XPS cell module (left side). <br><br><br>

Fig. 2: Scheme of the NAP-HE-XPS endstation installed at the ISISS beamline.
The spectrometer (right site) is displayed retracted from the XPS cell module (left side).


Table 1: Gas analytics<br><br><br>

Table 1: Gas analytics


Table 2: Laboratory facilities at ISISS<br><br><br>

Table 2: Laboratory facilities at ISISS



Obviously, the understanding of the interaction of a catalyst surface with the reactants plays a key role in a detailed description of catalytic processes. X-ray photoelectron spectroscopy (XPS) is a well-established powerful tool to study in detail the outermost surface of solids but it was traditionally restricted to high vacuum and low pressure conditions. However, recently a methodology based on a differentially pumped electrostatic lens system has gained much interest.

The Fritz-Haber-Institut der MPG has operated at BESSY such an instrument since 2002 at different undulator based beamlines. In 2007 a beamline (ISISS) dedicated to near ambient pressure  XPS (NAP-XPS) experiments has been implemented at HZB/BESSY II. A further improved version of this instrument is installed as the ISISS beamline since June 2013. A picture of the set-up can be seen as Fig. 1 while Fig. 2 shows a sketch of the main components.