ISISS station

Innovative Station for In Situ Spectroscopy

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.

 

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)


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


Liste von Publikationen
Station data
NAP-HE-XPS
Temperature range room temperature up to 1000 K
Pressure Range
Detector 2D delay line detector (2D DLD) (SURFACE CONCEPT, Mainz)
Manipulators various, optimised for sample environment
Sample holder compatibility
Beamline(s)

ISISS

maximum pressure 2000 Pa
minumum pressure 10-10 Pa
typical pressure 100 Pa
gas analytics
  • electron impact mass spectrometer (differentially pumped)
  • proton-transfer-reaction mass spectrometer (PTR-MS)
  • micro gas chromatograph

Methods

NEXAFS, XPS
  • X-ray photoelectron spectroscopy (XPS) under high vacuum (p=10-10 Pa) and near ambient pressure conditions (typically p=100 Pa).
  • X-ray aborption spectroscopy (XAS) at pressure up to 1k Pa with NAP-HE-XPS endstation. Installation of variable pressure XAS endstation instead of NAP-HE-XPS system allows NEXAFS in electron yield mode at variable pressure between 1 - 100 kPa at temperatures up to 650K.