Gold nanoparticles on Fe-doped Co3O4 for enhanced low-temperature CO oxidation

A series of Au/Co x Fe 3- x O 4 catalysts was synthesized using the sol-deposition method by depositing 2–5 nm Au particles on Fe-doped Co 3 O 4 . Co 2 FeO 4 , with a Co/Fe molar ratio of 2:1, exhibited higher specific surface area , Co 3+ /Co 2+ ratio, and oxygen vacancy content compared to Co 3 O 4 . As a result, it displayed better performance in CO oxidation , achieving a total conversion temperature ( T 100 ) of 96 °C. Au greatly improved the catalytic efficiency of all Co x Fe 3- x O 4 samples, with the 0.2%Au/Co 2 FeO 4 catalyst achieving a further decrease in T 100 to 73 °C. Stability tests conducted at room temperature on the 1%Au/Co x Fe 3- x O 4 catalysts demonstrated a slowed deactivation rate after Fe-doping. The reaction pathway for CO oxidation catalyzed by Au/Co 2 FeO 4 followed the Mars-van Krevelen mechanism.