Figure 1. Periodic redox operation of the 5 wt% Pt/Al₂O₃ catalyst at 298 K.

(a) Transient evolution of CO₂ observed during exposure of a pre-reduced Type-94 (Johnson Matthey) 5 wt% Pt/Al₂O₃ catalyst to 5 vol% CO/Ar (shaded area), followed by a switch to 21 vol% O₂/He at 298 K. The left-hand axis reports the evolution of CO₂ in terms of molecules per second (black), the right-hand axis shows the cumulative CO₂ production as a fraction of the total number of Pt atoms in the catalyst bed (blue). (b) Repeated cycles of a similar (shorter oxidizing cycle) experiment shown in a: black=5 wt% Pt/Al₂O₃; red=Al₂O₃. (c) Cumulative CO₂ (molecules) production during the experiment shown in b.