New thesis shows tiny differences inside materials can shape big climate solutions

These materials contain many tiny active sites where chemical reactions take place. Researchers have often assumed that chemically identical active sites behave in the same way. PhD candidate Chenxi Li shows that this is not always true.

Using advanced computer simulations, the thesis reveals that the local environments surrounding active sites can vary depending on their positions within a material, influencing their chemical reactivity. 

– With the computational tools and methods we have developed, we can now investigate these differences more precisely and use this knowledge to design better materials, Chenxi Li says.

"Workbenches" in materials
An active site is like a tiny “workbench” inside a material, where important chemical reactions take place. These materials, called metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), contain networks of small pores and channels. When a molecule such as carbon dioxide or water enters the material, it may need to travel through these channels to reach an active site before a reaction can occur. 

The thesis shows that even chemically identical active sites can behave differently depending on their local environments. Some are easy for molecules to reach, while others are buried deeper inside, where molecules arrive more slowly. Their surrounding chemical environments can also influence reaction energetics, making certain sites more reactive than others. These differences in site accessibility and reactivity can affect the overall performance of the material. This helps explain why a material that looks promising on paper may not perform as well in real devices. 

New digital tools
To tackle this challenge, the thesis introduces new computational tools and methods that make it easier to study and design these materials. 

One of them, MOFBuilder, automatically builds realistic models of porous materials and enables simulations of how their structures and internal pores move and change over time. This tool can speed up the development of better materials for clean energy applications, including hydrogen production. Read more in the article Computer software makes it easier to produce clean fuel out of hydrogen . The thesis also presents a new computational method that can help identify promising materials for capturing carbon dioxide, described in New method could accelerate the search for future carbon capture materials .

Together, these results give researchers new ways to understand and design more efficient and reliable materials for a sustainable energy future.

THE THESIS
Read the thesis here: Computational Studies of Electrocatalytic Sites: From Molecules to Framework Environments

THE DISSERTATION
The dissertation is October 20 at 09.00 2026. Read more about it here.