The time on stream during which the @O04322@ for the catalytic reaction, \(k\), falls to a specified fraction of its original value, often 0.5.
PAC, 1976, 46, 71. (Manual of Symbols and Terminology for Physicochemical Quantities and Units - Appendix II. Definitions, Terminology and Symbols in Colloid and Surface Chemistry. Part II: Heterogeneous Catalysis
) on page 83 [Terms