Sm 2 O 3 /Co 3 O 4 catalysts prepared by dealloying for low-temperature CO oxidation.

A series of Co 3 O 4 catalysts modified by Sm were prepared by a combined dealloying and calcination approach, and the catalytic activities were evaluated using CO catalytic oxidation. The Sm 2 O 3 /Co 3 O 4 catalysts were composed of a large number of nanorods and nanosheets, and exhibited a three-dimensional supporting structure with pores. The experimental results revealed that the addition of a small amount of Sm into the precursor AlCo alloy led to a dealloyed sample with improved catalytic activity, and the dealloyed Al 90 Co 9.5 Sm 0.5 ribbons (0.5 Sm 2 O 3 /Co 3 O 4 ) calcined at 300 °C showed the highest activity for CO oxidation with complete CO conversion at 135 °C, moreover, CO conversion almost no attenuation, even after 70 hours of catalytic oxidation, which is superior to that of Co 3 O 4 . The enhanced catalytic activity of the Sm 2 O 3 /Co 3 O 4 catalyst can be attributed to the large specific surface area, more reactive oxygen species and Co 3+ ion, as well as electronic interactions between Sm and Co.