Answer
Ryoji Noyori studied hydrogenation reactions for his Nobel-winning research. Hydrogenation reactions are chemical reactions that add hydrogen to other substances. They are important in the production of many different products, including fuels, plastics, and pharmaceuticals. Noyori developed new catalysts that made hydrogenation reactions more efficient and economical. This work has had a major impact on the chemical industry and has led to the development of new drugs and other products.