Fe-Promoted Copper Oxide Thin-Film Catalysts for the Catalytic Reduction of N2O in the Presence of Methane

Thin-film catalysts are recently recognized as promising catalysts due to their reduced amount of materials and good catalytic activity, leading to low-cost and high-efficiency catalysts. A series of CuFeOx thin-film catalysts were prepared with different Fe contents using a one-step method as well as tested for the catalytic reduction of nitrous oxide (N2O) in the presence of CH4 at a high GHSV of 185 000 mL/(g·h). The increase of iron strongly affects the dispersion and leads to the creation of a less-active segregated Fe2O3 phase, which was confirmed by XRD, EDX, and XPS outcomes. The results show that the synergistic properties between Cu and Fe, which affect the CuFeOx film catalysts in many aspects, such as the hollow-like texture, specific surface area, nano-crystallite size, the surface contents of Cu+, Fe3+, and oxygen species, the reductive strength and the strong active sites on the surface. Using DFT calculations, the adsorption and decomposition energy profiles of N2O on the CuFeO2 (012) surface model were explored. The surface Fe-site and hollow-site are active for N2O decomposition, and the decomposition energy barriers on the Fe-site and the hollow-site are 1.02 eV and 1.25 eV respectively at 0 K. The strategy adopted here to tailor the activity through low-doping Fe-oxide catalysts could establish a promising way to improve the catalytic reduction of N2O with CH4.