Transition metals are a group of chemical elements that are characterized by their partially filled d-orbitals, which give them unique properties such as variable oxidation states, complex formation, and catalytic activity.
Transition metals are commonly used as catalysts in industrial processes such as the Haber-Bosch process for ammonia synthesis, the Fischer-Tropsch process for hydrocarbon synthesis, and the production of polyethylene terephthalate (PET) from ethylene glycol and terephthalic acid. They are also used in the production of steel and other alloys, as well as in electronic and magnetic materials, batteries, and fuel cells.
Moreover, due to their unique electronic properties, they also play a critical role in biological systems, where they participate in a wide range of biochemical reactions, such as oxygen transport in hemoglobin and myoglobin, electron transfer in photosynthesis, and hydrogen production in hydrogenases.