Dynamical Response of Catalytic Systems in a Cs Corrected Environmental TEM

Thomas W. Hansen
Funding: DTU Cen

In industrialized countries, 85-90% of chemical production involves catalytic processes. Catalysis research relies heavily on transmission electron microscopy (TEM) for microstructural characterization. In order to optimize the active surface area, many catalysts consist of metals or metal alloys, deposited onto a support material as nanoparticles. In a catalytic reactor, the particles tend to grow in size under reaction conditions (high temperature and pressure) resulting in the loss of active surface area and catalytic activity. This phenomenon is known as sintering.

Several models of the sintering process have been proposed based on investigations carried out post mortem, revealing only the final state of the catalyst, not the process as it happens. To investigate this phenomenon further we use model systems consisting of nanoparticles on flat substrates. Such samples allow for in-depth investigations of the particles and their internal dynamics. Such investigation are necessary in order to develop sinter-resistant catalyst systems and provide valuable insight for future generations of catalysts.

Here, we will investigate sintering using high-resolution TEM with high-speed cameras to observe the processes at atomic resolution.

 

Learning objectives

  • Learn to use transmission electron microscopy
  • Understand the importance of catalysis in energy production and society
  • Use automated analysis
  • Learn the dynamics of nanoparticles

      

Frames extracted from a movie recorded in the Environmental TEM showing Au particles in a hydrogen atmosphere. The frames indicate how two particles with a diameter of ca. 5 nm merge into a single particle over time. 

Open to: Bachelor, Master, PhD and Special Project students

 

 

Thomas Willum Hansen
Senior Researcher
DTU Cen
+45 45 25 64 76