Fig. 4: New catalyst breaks a general activity/stability tradeoff in the CO oxidation reaction.

a–c Activity, measured as the temperature required to attain 50% CO conversion (T₅₀) under a constant WHSV (on a per Pt basis) for various representative Pt/CeO₂ catalysts as a function of their activation/reaction history (the X axis denotes the gas and temperature of the treatments, run in sequence from left to right). a shows the results for Pt/CeO₂-HS and Pt/CeO₂-LS; (b) for 3.5%Pt/CeO₂; and (c) for Pt/CeO₂-Derived. d CO oxidation activity at 80 °C, as a TOF (mol of CO converted per mol of Pt and second, calculated at conversions lower than 20 %), of the Pt/CeO₂-Derived sample compared to other reference materials, after catalysts had been subjected to O₂-rich reaction conditions in the range 200–400 °C^{25,36,50,51,52} (bottom graph) or 400–500 °C^1,2,53 (top graph); number of top of bars denote the reference number; e Direct comparison of the initial TOF vs the aged TOF for catalysts depicted in (d); f Representation of the initial TOF vs the catalyst stability (aged TOF/initial TOF x 100) for catalysts aged in an O₂-rich stream at 300 °C. In (e) and (f), solid gray circles denote cationic single Pt atoms on CeO₂; pink circle denotes Pt⁰ nanoparticles in zeolites, red circle denotes Pt⁰ nanoparticles on CeO₂ at high Pt loadings; orange and green circles denote mostly Pt⁰ nanoparticles on CeO₂ at low Pt loadings (high surface area and lower surface area CeO₂, respectively); and blue circle denotes mostly Pt⁰ nanoparticles on V-pocketed CeO₂ (this work). The color-shaded areas cluster the different materials as per the activity/stability relationship in (f): Pt/zeolite (metallic nanoparticles) and Pt₁/CeO₂ (single Pt atoms) show at the top left corner, corresponding to low activity/high stability (yellow shade); common reduced Pt/CeO₂ catalysts (low Pt loadings) show high activity/low stability (blue area); reduced, high Pt loading Pt/CeO₂ samples show low activity/low stability (red shade); and the CO-activated Pt/CeO₂-Derived sample in this work shows high activity/high stability (green shade).