Towards STM of catalytic reactions

CatLab Highlight Lecture

  • Date: Nov 2, 2022
  • Time: 12:30 PM - 02:00 PM (Local Time Germany)
  • Speaker: Prof. Dr. Joost Wintterlin
  • Department Chemie and CeNS Ludwig-Maximilians-Universität München
  • Location: Albert-Einstein Straße/Magnusstraße, 12489 Berlin, HZB
  • Room: BESSY Lecture Hall & Online
  • Host: Prof. Dr. Robert Schlögl
  • Contact:
Towards STM of catalytic reactions
Scanning tunneling microscopy (STM) regularly offers atomic resolution, can work at high pressures and only interacts weakly with matter - seemingly perfect conditions for gaining access to the microscopic processes on a catalyst surface. On the other hand, the number of examples in which working catalysts have actually been imaged with the STM has remained small.

This contradiction is due not so much to fundamental problems as to numerous practical, experimental difficulties. In this talk, I present the results of our efforts to resolve some of these difficulties. In one project, a combination of a high-pressure STM and a special gas chromatograph was developed. With this system, the co-catalyzed Fischer-Tropsch synthesis, an industrial process for the production of liquid hydrocarbons from mixtures of CO and H2 (synthesis gas), was investigated. Under reaction conditions, Co single crystals serving as model catalysts were imaged with atomic resolution and the catalytic turnover frequency was measured under the same conditions. The correlations in these data provide clear indications of the active sites of this reaction. In a second project, high-speed STM technique was further developed in order to investigate dynamic processes in the adsorption layer. Surface diffusion, which determines collision rates between reacting particles on a catalyst surface, was studied. It is shown that diffusion can be extremely fast even at the high coverages typically present on an operating catalyst. A novel 2D lattice diffusion mechanism is proposed.Registration for participants on site and online is necessary, please use the following link:

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