Typically, STM experiments are performed under vacuum. However, STM does not involve free electrons, so that it can, in principle, be used at arbitrary pressures, unlike most classical surface science methods. Using this property of STM we have developed an apparatus to perform experiments at pressures close to those applied in industrial catalysis. Our goal is to obtain atomically resolved images from operating catalysts.
Combined high-pressure cell with the STM (right-hand side) and UHV chamber (left hand side). The STM can operate between UHV and 1 bar and up to 250 °C. Reprinted with permission from "A high-pressure scanning tunneling microscope for studying heterogeneous catalysis", M. Rößler, P. Geng, J. Wintterlin, Rev. Sci. Instrum. 76, 023705 (2005). Copyright 2005, AIP Publishing LLC.