Chemistry allows us to design and build new molecules that improve our lives from medicines and crop
protectants to advanced materials. To create such molecules efficiently, chemists rely on catalysts: substances
that make reactions faster and cleaner by lowering the energy required and reducing waste. Among all known
elements, selenium stands out because it can easily switch between different chemical states, including rare
ones that contain unpaired electrons called radicals. These radicals are highly reactive and can drive chemical
transformations in unique ways, yet their behavior in catalytic processes is still poorly understood. Our project,
THREE, will uncover how selenium radicals form, how they react, and how they can be reused in catalytic
cycles. By combining experiments and computer modeling, we aim to reveal the basic rules that govern their
stability and reactivity. Understanding these principles will open new directions for sustainable chemistry,
helping scientists design future catalysts that use abundant and less toxic elements instead of precious metals.