The role of the so-called oxygen storage and release capacity (OSC) in promoting the activity of noble metals in the three-way catalysts (TWCs) is critically discussed. It is shown that the promoting effects of CeO2 in the TWCs cannot be attributed to a simple redox type of effect according to the reaction CeO2 .tautm. CeO2 - x + x/2O2, since multiple and sometimes intriguing effects of CeO2 promoter have been obsd., particularly in the latest generation of TWCs contg. modified CeO2-ZrO2 mixed oxides.
