Substrate-decoupled 2D MOF for Single-Atom Catalysis

Catalysts are important because they lower the energy needed for chemical reactions and are sometimes essential for the reaction to happen. Often, the best catalysts use rare and expensive metals like platinum and palladium. As we work towards a CO2-neutral future, these metals are becoming more in demand, in turn making them more expensive. Furthermore, natural deposits are insufficient to meet future demands. An exciting development in this field is the creation of single-atom catalysts (SACs). These catalysts utilize individual atoms instead of larger quantities of material. This new method could greatly reduce the need for these rare metals, making it more sustainable and cost-effective. However, SACs still have many challenges to overcome before they can be used effectively in real-world settings. Researchers are working hard on laboratory-made catalysts, to better understand and improve them. They are comparing these laboratory-made SACs to theoretical ideas to help make them more effective and usable for industries. A big challenge in these studies is making sure all the single atoms are the same, i.e. react chemically in the same way. In many SACs, atoms are in different environments, which can significantly change how they behave and make comparisons to theory more challenging. Considering this, our project is leading this research by using metal-organic frameworks (MOFs) as our model system. MOFs are made of single metal atoms connected by organic molecules, creating a uniform environment for each atom. This uniformity ensures all atoms act similarly. By choosing different organic molecules to connect the atoms, we can change the environment and adjust the properties of each atom. While this approach is known, it has yet to be used at the atomic level, especially in terms of reactivity and catalysis. A unique part of our research is using graphene sheets as a base for the MOFs. Graphene is ideal because it doesn`t react much with other substances, letting us study our SACs isolated and very closely. We use advanced imaging techniques to localize the single atoms, and spectroscopies to measure the effectivity of these catalysts. With these techniques, we can directly observe and tweak our catalysts at the atomic level, opening up new possibilities for improving catalytic efficiency and sustainability. This research is helping pave the way for more cost-effective and environmentally friendly ways to use catalysts, which is key for sustainable industrial practices.