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 CoOx 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. Direct catalytic decomposition offers a green approach for N2O abatement, however, catalytic performance is severely limited by slow oxygen desorption kinetics and the intrinsic electronic structure of active sites. Here, the authors introduce iron species into a Co/β zeolite catalyst to precisely tailor the microstructure of cobalt active sites and optimize oxygen desorption pathways, significantly promoting NO-assisted oxygen desorption during N2O decomposition and improving the catalytic active site.