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

In order to enhance the catalytic performance of the Gd-modified Co 3 O 4 catalyst (Gd 0.06 Co) for the N 2 O decomposition, alkali metal K was introduced as the promoter by impregnating the Gd 0.06 Co powder with an aqueous solution of KNO 3 (with K/Co ratios 0.01–0.05). With the doping of K, the catalytic activity over Gd 0.06 Co was significantly improved and the temperature of N 2 O complete decomposition was decreased from 350 °C to 300 °C. Combining the results of XPS and O 2 -TPD, the superior catalytic performance of the optimum catalyst K 0.025 Gd 0.06 Co 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% O 2 , 100 ppmv NO and 2 vol% H 2 O, the K 0.025 Gd 0.06 Co catalyst exhibited prominently better catalytic activity than Gd 0.06 Co and K 0.025 Co catalysts.