Johnson Matthey Plc is a British multinational specialty chemicals and sustainable technologies company that develops and supplies catalysts, precious metal products and related services to the automotive, energy, chemicals and other industries. Founded in 1817 and headquartered in London, United Kingdom, the company operates globally with manufacturing sites and offices across multiple countries, serving customers in transport, energy, chemicals, PGMs and circularity markets. Its core products and services encompass emission control catalysts including three-way catalysts, selective catalytic reduction systems, diesel particulate filters and gasoline particulate filters for light and heavy-duty vehicles; platinum group metals refining, recycling, trading and industrial products such as thermocouple wires, spark plug components and sensor materials; process catalysts and licensing for ammonia, nitric acid, formaldehyde, methanol, petrochemicals, edible oils, biorenewables and sustainable aviation fuels; hydrogen technologies including fuel cell catalysts and membrane electrode assemblies; and PGM chemicals, additives and purification solutions. In May 2025, Johnson Matthey agreed to sell its Catalyst Technologies business, which provides process technology licensing and catalysts for chemical and fuel value chains, to Honeywell International Inc for an enterprise value of GBP 1.8 billion in cash, with the transaction expected to close by the first half of 2026 and proceeds enabling a GBP 1.4 billion return to shareholders; this follows the 2024 divestment of its Medical Device Components business to Montagu Private Equity for USD 700 million, repositioning the group as a streamlined entity focused on Clean Air and PGM Services segments with enhanced cash generation targets of at least GBP 250 million free cash flow by fiscal 2027/28.