Potassium promoted Gd0.06Co catalysts for highly efficient catalytic N2O decomposition in presence of impurity gases at low temperature.

ABSTRACT

In order to enhance the catalytic performance of the Gd-modified Co3O4 catalyst (Gd0.06Co) for the N2O decomposition, alkali metal K was introduced as the promoter by impregnating the Gd0.06Co powder with an aqueous solution of KNO3 (with K/Co ratios 0.01-0.05). With the doping of K, the catalytic activity over Gd0.06Co was significantly improved and the temperature of N2O complete decomposition was decreased from 350 °C to 300 °C. Combining the results of XPS and O2-TPD, the superior catalytic performance of the optimum catalyst K0.025Gd0.06Co was mainly owing to the synergistic effect of Gd and K, which weakened the Co-O bond and endowed the catalyst surface with much more amount of oxygen vacancies. Even under the coexist of the impurity gases, such as 5 vol% O2, 100 ppmv NO and 2 vol% H2O, the K0.025Gd0.06Co catalyst exhibited prominently better catalytic activity than Gd0.06Co and K0.025Co catalysts.