Enhancement of N2O decomposition performance by co-doping of Ni and Y to Co3O4 catalyst

Abstract

Co3O4, Y2O3-Co3O4 and NiO-Y2O3-Co3O4 samples were prepared by the simple co-precipitation method, and their N2O catalytic decomposition performance was evaluated. Experimental results disclose that the order of catalytic activity among the three catalysts is NiO-Y2O3-Co3O4 > Y2O3-Co3O4 >> Co3O4. N2O conversion over NiO-Y2O3-Co3O4 catalyst reached 100 % at 360 °C, which was 20 °C and 60 °C lower than those over Y2O3-Co3O4 and Co3O4, respectively. In addition, NiO-Y2O3-Co3O4 catalyst shows better water resistance compared with Co3O4 and Y2O3-Co3O4. Systems-based characterization techniques, it is confirm that Y and Ni were successfully doped into Co3O4, where Y was on the surface and Ni was mainly in the bulk phase. Due to the co-doping of Y and Ni, NiO-Y2O3-Co3O4 catalyst has smaller average particle size and reinforced surface alkalinity. Furthermore, the surface modification of Y enhances the electron-donating capacity of Co2+ and oxygen desorption ability, while bulk phase doping of Ni facilitates the reduction of Co3+ to Co2+ and weakens Co-O bond in Co3O4, which endow NiO-Y2O3-Co3O4 sample with lower Ea for N2O decomposition. Therefore, NiO-Y2O3-Co3O4 catalyst exhibits the best N2O catalytic decomposition performance.