Strong Structural Modification of Gd to CoO for Catalyzing NO Decomposition under Simulated Real Tail Gases.

In this paper, Gd-promoted CoO catalysts were prepared via a facile coprecipitation method for low-temperature catalytic NO decomposition. Due to the addition of Gd, the crystallite size of CoO in the GdCo catalyst surprisingly decreased to 4.9 nm, which is much smaller than most additive-modified CoO catalysts. This huge change in the catalyst's textural structure endows the GdCo catalyst with a large specific surface area, plentiful active sites, and a weak Co-O bond. Hence, GdCo exhibited superior activity for catalyzing 2000 ppmv NO decomposition, and the temperature for the complete catalytic elimination of NO was as low as 350 °C. Meanwhile, compared with pure CoO, decreased from 77.4 to 46.8 kJ·mol and of the reaction increased from 1.16 × 10 s to 5.13 × 10 s at 300 °C. Moreover, GdCo displayed a quite stable catalytic performance in the presence of 100 ppmv NO, 5 vol % O, and 2 vol % HO.