Johnson Matthey Plc engages in the clean air, catalyst and hydrogen technology, and platinum group metals (PGM) service businesses in the United Kingdom, Germany, rest of Europe, the United States, rest of North America, China, rest of Asia, and internationally. It operates through five segments: Clean Air, PGM Services, Catalyst Technologies, Hydrogen Technologies, and Value Businesses. The Clean Air segment provides catalysts for emission control after-treatment systems to reduce harmful emissions from cars, other light duty vehicles, trucks, buses, and non-road equipment powered by internal combustion engines. The PGM Services segment enables the energy transition that offers circular solutions as demand for critical materials. This segment also offers PGM refining and recycling, and trading services; other precious metal products; and PGM chemicals, industrial products, and catalysts. The Catalyst Technologies segment is involved in decarbonization of chemical and fuel value chains. This segment also provides speciality catalysts and additives; process technology licenses; and engineering design services. The Hydrogen Technologies segment offers catalyst coated membranes that are a critical component for fuel cells and electrolysers. The Value Businesses segment business portfolio includes precious metal pastes and enamels, and battery systems and products for devices used in medical procedures; and detection and measurement solutions. The company was formerly known as Johnson & Cock and changed its name to Johnson Matthey Plc in 1851. Johnson Matthey Plc was founded in 1817 and is based in London, the United Kingdom.