Prolonged operation of compact sealed CO₂ TEA lasers has been achieved at pulsed repetition frequencies up to 100 Hz, with the high CO₂ levels (50% and above) needed for maximum peak power output per unit discharge volume. This has hitherto been prevented by the inability to recombine the dissociation products CO and O₂ rapidly enough in high-CO₂, high-PRF conditions. This has now been achieved through the first use of an unheated SnO₂-Pd catalyst (active at -26°C) placed in the mainstream of gas circulated inside the laser. More than 2.5 × 10⁶ pulses have been obtained, with no evidence of a limit to the life through decline in catalyst activity or deterioration of the gas discharge