Improved instrumentation to carry out surface analysis and to monitor chemical surface reactions in situ on small area catalysts over a wide pressure range (10−8–105 Torr)

Improved one-tier and two-tier designs for a high-pressure–low-pressure (HPLP) apparatus are described together with some of their recent applications. These instruments are used for surface analysis and in situ monitoring of catalytic reactions on small samples with a geometrical surface area of 1 cm2. Catalytic reactions are studied over a wide range of pressures (10−8–105 Torr) and temperatures (273–1273 K). The apparatus incorporates surface analysis methods such as Electron Spectroscopy for Chemical Analysis (ESCA), High Resolution Electron Energy Loss Spectrometry (HREELS), and 14C-radiotracer labeling in addition to Low Energy Electron Diffraction (LEED), Auger Electron Spectroscopy (AES), and mass spectrometry. Facilities are also available for argon sputter-ion cleaning, deposition of adsorbates by evaporation, and coverage calibration by means of a thickness monitor.