An apparatus for fabrication, surface analysis in ultrahigh vacuum, and testing of the catalytic activity of model metal alloy catalysts is described. Arrays of model catalysts are produced by electron-beam deposition of up to four metals simultaneously onto a substrate. The surface analysis techniques available are scanning electron microscopy, x-ray photoemission spectroscopy, ion scattering spectroscopy, Auger electron spectroscopy, sputter profiling, and temperature programmed desorption. The catalytic activity of the model catalysts is tested individually by scanning a combined gas delivery and gas sampling device over the sample surface. The gas sampled is analyzed with mass spectrometry. Experiments can be made at pressures up to 1 bar and temperatures up to 500 °C. It is shown that the lateral resolution is better than 0.2 mm and that up to 20 circular spots, 1 mm in diameter, can be studied on a substrate 10 mm in diameter. A high pressure cell with an all-metal sealed ultrahigh vacuum lock is also described as part of the work.
Combined high-pressure cell–ultrahigh vacuum system for fast testing of model metal alloy catalysts using scanning mass spectrometry
M. Johansson, J. Hoffmann Jørgensen, I. Chorkendorff; Combined high-pressure cell–ultrahigh vacuum system for fast testing of model metal alloy catalysts using scanning mass spectrometry. Rev. Sci. Instrum. 1 June 2004; 75 (6): 2082–2093. https://doi.org/10.1063/1.1753677
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