PhD Project by William Bang Lomholdt
Project Title: High-resolution transmission electron microscopy of catalytic nanoparticle surfaces
Group: Atomic-Scale Materials Dynamics
Supervisor: Thomas Willum Hansen
Project Description
High resolution (HR) electron microscopy (EM) in general and transmission EM (TEM) in particular is a well-developed method to investigate samples at the sub-nanometer and even atomic scale. In fields such as energy conversion and micro- and nanoelectronics, it has become an essential tool for verifying the design of modern materials. In catalysis, atomic scale microscopy is used to investigate structural behavior.
In the presence of gases and at elevated temperature, TEM is used to investigate catalysts in-situ to obtain the structural behavior during reaction. This approach is known as environmental transmission electron microscopy (ETEM).
Such investigations often generate massive amounts of data. Exhaustive analyses of this vast amount of data is not only time consuming, but can also be flawed by human error. Machine-learning, especially deep learning, algorithms is a viable route to analyze these data sets efficiently and unbiased by the human factor. These algorithms are developed in close collaboration with researchers at DTU Physics.
In this project, we aim at unravelling the dynamics of surface structures using ETEM. In order to do this, we will firstly be investigating the role of the high-energy electron beam. The surface dynamics can be strongly influenced by high electron dose-rates, in particular under non-vacuum conditions. Once this is established, pursuits of the influence of gaseous atmospheres and elevated temperatures are commenced, including particular emphasis on transient phenomena such as sur-face and particle diffusion occurring during changing the conditions.
Group: Atomic-Scale Materials Dynamics
Supervisor: Thomas Willum Hansen
Project Description
High resolution (HR) electron microscopy (EM) in general and transmission EM (TEM) in particular is a well-developed method to investigate samples at the sub-nanometer and even atomic scale. In fields such as energy conversion and micro- and nanoelectronics, it has become an essential tool for verifying the design of modern materials. In catalysis, atomic scale microscopy is used to investigate structural behavior.
In the presence of gases and at elevated temperature, TEM is used to investigate catalysts in-situ to obtain the structural behavior during reaction. This approach is known as environmental transmission electron microscopy (ETEM).
Such investigations often generate massive amounts of data. Exhaustive analyses of this vast amount of data is not only time consuming, but can also be flawed by human error. Machine-learning, especially deep learning, algorithms is a viable route to analyze these data sets efficiently and unbiased by the human factor. These algorithms are developed in close collaboration with researchers at DTU Physics.
In this project, we aim at unravelling the dynamics of surface structures using ETEM. In order to do this, we will firstly be investigating the role of the high-energy electron beam. The surface dynamics can be strongly influenced by high electron dose-rates, in particular under non-vacuum conditions. Once this is established, pursuits of the influence of gaseous atmospheres and elevated temperatures are commenced, including particular emphasis on transient phenomena such as sur-face and particle diffusion occurring during changing the conditions.
Contact
Willy Bang Lomholdt PhD student
Contact
Thomas Willum Hansen Professor