French chemist who made important contributions to industrial chemistry and discovered cellulose, a basic constituent of plant cells.

Payen, the son of an industrialist, was put in charge of a borax-refining (borax) plant in 1815. He broke the Dutch monopoly on borax—most of which was mined in the Dutch East Indies—by discovering a process for producing borax from boric acid. In 1820 he turned his efforts to refining beet sugar. Two years later he introduced the use of activated charcoal to remove coloured impurities from beet sugar. In 1833 he discovered and isolated diastase (amylase), the first enzyme (organic catalyst) to be obtained in concentrated form. He then pursued the extensive analysis of wood and its components that culminated in the discovery of cellulose. He became professor of industrial and agricultural chemistry in 1835 at the Central School of Arts and Manufactures, Paris. Among his other contributions were studies of starch and bitumen and the discovery of pectin and dextrin.