Johnson Matthey Plc engages in the manufacture of measuring devices. The firm's products include ammonia and nitric acid, edible oils, formaldehyde, methanol, and petrochemicals. It operates through the following segments: Clean Air, PGM Services, Catalyst Technologies, Hydrogen Technologies, and Value Businesses. The Clean Air segment offers catalysts for emission control after-treatment systems used in light and heavy duty vehicles powered by internal combustion engines. The PGM Services segment enables the energy transition through providing circular solutions. The Catalyst Technologies segment is involved in the decarbonization of chemical and fuel value chains. The Hydrogen Technologies segment provides catalyst coated membranes for fuel cells and electrolysers. The Value Businesses segment refers to the portfolio of businesses managed by the firm. The company was founded by Percival Norton Johnson in 1817 and is headquartered in London, the United Kingdom.