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 Check text below. For more details contact the station manager.
Detector 2D delay line detector (2D DLD) (SURFACE CONCEPT, Mainz)
Manipulators various, optimised for sample environment
Sample holder compatibility Check text below. For more details contact the station manager.
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.