Near-ambient-pressure angle-resolved photoemission spectroscopy (ARPES) for operando probing of surface band structure.

Abstract

We present a fully operational near-ambient pressure angle-resolved photoemission spectroscopy (NAP-ARPES) setup for operando studies of surface band structures under gas exposure at the TEMPO beamline of Synchrotron SOLEIL. The system integrates a SPECS PHOIBOS 150 NAP analyzer with multi-stage differential pumping and precise sample manipulation, enabling momentum-resolved electronic structure measurements under conditions approaching realistic environments. Commissioning experiments on graphite, ZnO(10-10), Cu(111), and Ru(0001) demonstrate operando capabilities, including reversible hydrogenation and adsorbate-induced modifications to the band structure. By bridging the gap between conventional UHV ARPES and operando surface science, this development provides a robust platform for investigating catalytic surfaces, energy conversion materials, and reactive interfaces under near-ambient conditions.