HP-STM operates similarly to traditional STM but incorporates specialized equipment to maintain high pressure environments. The basic principle involves a sharp tip that scans the surface of a material, measuring the tunneling current that flows between the tip and the surface. This current is sensitive to the atomic-scale topography of the surface. In HP-STM, the sample is enclosed in a high-pressure cell that can be filled with gases such as hydrogen, oxygen, or carbon monoxide, which are commonly involved in catalytic reactions.
