A simple method for determining the speed of oxygen release from Pt/CeO 2 –ZrO 2 materials is proposed. We determined the speed of oxygen release from three differently prepared Pt(1wt%)/CeO–ZrO 2 catalysts by two methods: the method employing temporal analysis of products (TAP) reactor with CO, O 2 , and CO 2 pulsed gases, and a conventional method with CO and O 2 switch gases. Strong CO 2 adsorption precluded correct analysis of oxygen release speed, when it was determined from the amount of CO 2 formed. Therefore, instead of the amount of CO 2 formed, we suggested the t max value, defined as the position of maximal intensity of CO 2 transient responses obtained upon low-intensity (10 15 –10 16 molecules) CO pulsing in the TAP reactor. Shorter the t max value, higher the rate of oxygen release, because the temperature dependence of the t max determined in the present study resembles the previous results of oxygen release analysis [T. Tanabe, A. Suda, C. Descorme, D. Duprez, H. Shinjoh, M. Sugiura, Stud. Surf. Sci. Catal. 138 (2001) 135].