Enhancing NO-assisted oxygen desorption for efficient N₂O decomposition by introducing iron into Co/β catalysts

Direct catalytic decomposition is one of the green methods for N₂O elimination. However, the activity of catalyst is limited by the slow oxygen desorption rate and the unsatisfactory electronic structure of the active site. In this work, Fe species were introduced into Co/β catalyst to regulate the microstructure of Co active sites and oxygen desorption pathways. A combination of characterization techniques such as XRD, TEM, XPS, DR UV-Vis, etc were employed to elucidate the nature of Co and Fe species in the catalysts. The results demonstrated that the introduction of Fe not only reduced the particle size of CoO_x species, but also effectively improved the reducibility and deoxygenation capacity of the catalysts. Moreover, in-situ FT-IR and N₂O-TPD experiments revealed that the oxidization of N₂O to NO and the decomposition of nitrate species were significantly enhanced over Fe doped Co/β catalyst, thereby facilitated the NO-assisted oxygen desorption process during N₂O decomposition. As a result, the N₂O conversion at 420 °C was elevated from 85% of Co/β catalyst to 100% of 1.0Fe-Co/β catalyst, which is much higher than the 22% conversion achieved over Fe/β catalyst. This work could provide the reference for the design of N₂O decomposition catalysts and understanding of catalytic reaction mechanism.