Lecture
Van Marum Colloquium: Near-ambient pressure XPS/NEXAFS at Diamond Light Source
- Date
- Thursday 3 April 2025
- Time
- Location
-
Gorlaeus Building
Einsteinweg 55
2333 CC Leiden - Room
- CE.0.18
Abstract
The near-ambient-pressure VerSoX (Versatile Soft X-ray) beamline at Diamond Light Source opened for users 2017. It features two branch lines with endstations covering pressures from UHV to atmosphere. The energy range 50/170 – 2200/2800 eV allows accessing the core levels of a wide range elements and is optimised for electron kinetic energies necessary to penetrate gas environments up to the 10 mbar regime. The differentially pumped beamline entrance and analyser of the NAP endstation enable measurements routinely up to 10-20 mbar. A small NEXAFS endstation is separated from the beamline by a window and allows pressures up to a few hundred mbar and the use of various cells for extending the range of sample environments for X-ray absorption spectroscopy to solid-liquid interfaces and gas pressures > 1 bar.
The talk will discuss the beamline design and performance and present results of experiments in ambient-pressure conditions, which demonstrate the research possibilities it offers in areas, such as catalysis and electrochemistry. Two examples are our recent work on size-selected Pd nano-catalysts for methane oxidation and IrO2 electro-catalysts for the oxygen-evolution reaction, which is part of the water splitting process for green hydrogen production.