ReactorAFM/STM – dynamic reactions on surfaces at elevated temperature and atmospheric pressure

Beilstein Journal of Nanotechnology, vol. 16, pp. 397–406

Abstract

Previous work has shown the ReactorSTM and ReactorAFM, capable of studying materials under industrially relevant conditions. Here we show current developments of the ReactorAFM/STM, implementing a qPlus sensor to add the ability of combining atomic force microscopy (AFM) and scanning tunneling microscopy (STM) techniques to study the geometric and electronic structure of materials under reaction conditions. We demonstrate this by imaging a Pd(100) single crystal at 450 K with combined AFM/STM. The surface is compared under ultrahigh vacuum and under 0.5 bar O 2 pressure showing a notable increase in RMS current, which we attribute to oxidation. Also, we study cobalt nanoparticle catalysts on an aluminum oxide support, industrially relevant in the Fischer–Tropsch synthesis. The catalysts are imaged before and after reaction at 430 K as the current maximum temperature of the qPlus sensor used falls just below the reaction temperature. Quadrupole mass spectrometry data show the reaction taking place by monitoring product gases during heating and cooling of the sample under CO and H 2 gas pressures of 2 bar. The monitored gases include H 2 O as byproduct and the hydrocarbons ethane ( m / z = 30), propane ( m / z = 44), and hexane ( m / z = 86), which all show increases in counts while between 490 and 550 K. The added ability to scan various surfaces with combined AFM/STM while monitoring the reaction products demonstrates the versatility offered by the ReactorAFM/STM to study catalysts under realistic industrial conditions.

Authors 11

1. Tycho Roorda Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, Rapenburg 70, Leiden, 2311 EZ, Netherlands

2. Hamed Achour Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, Rapenburg 70, Leiden, 2311 EZ, Netherlands

3. M. A. Van Spronsen Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Physics, Leiden University, Rapenburg 70, Leiden, 2311 EZ, Netherlands

4. Marta E. Cañas‐Ventura Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Physics, Leiden University, Rapenburg 70, Leiden, 2311 EZ, Netherlands

5. Sander B. Roobol Aachen

   Leiden University · ASML (Netherlands)

   Affiliation as printed

   ASML, Veldhoven, Netherlands

   Leiden Institute of Physics, Leiden University, Rapenburg 70, Leiden, 2311 EZ, Netherlands

6. Willem G. Onderwaater Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Physics, Leiden University, Rapenburg 70, Leiden, 2311 EZ, Netherlands

7. P. C. van der Tuijn Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Physics, Leiden University, Rapenburg 70, Leiden, 2311 EZ, Netherlands

8. Gertjan van Baarle Aachen Leiden Probe Microscopy

   Leiden University

   Affiliation as printed

   Leiden Probe Microscopy, Leiden University, Rapenburg 70, Leiden, 2311 EZ, Netherlands

9. Johan W. Bakker Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Physics, Leiden University, Rapenburg 70, Leiden, 2311 EZ, Netherlands

10. J.W.M. Frenken Aachen

    Leiden University

    Affiliation as printed

    Leiden Institute of Physics, Leiden University, Rapenburg 70, Leiden, 2311 EZ, Netherlands

11. Irene M. N. Groot Aachen

    Leiden University

    Affiliation as printed

    Leiden Institute of Chemistry, Leiden University, Rapenburg 70, Leiden, 2311 EZ, Netherlands