Fe-Beta catalysts prepared by heating wet ion exchange and their catalytic performances on N2O catalytic decomposition and reduction

A heating wet ion exchange method was successfully used to synthesize Fe-beta catalysts by controlling preparation conditions. The iron loading of Fe-beta catalysts increased from 0.88% to 16.56% with raising the ion exchange temperature from 20 to 90 degrees C. Their catalytic activities for N2O decomposition and N2O reduction by NH3 were evaluated. The activity results show that the catalyst prepared at 80 degrees C (Fe-beta-80 degrees C) could achieve complete N2O decomposition at 480 degrees C and N2O reduction by NH3 at 375 degrees C. The iron species of catalysts were further characterized by X-ray diffraction, transmission electron microscopy (TEM), UV-vis, H-2 temperature programmed reduction, and NH3 temperature programmed desorption techniques. The characterization results indicate that related high content of isolated Fe3+ ions and oligonuclear Fex3+Oy clusters existed in the Fe-beta-80 degrees C catalyst, which contributed to the high catalytic activity. Moreover, after the reaction of more than 100 h, Fe-beta-80 degrees C catalyst has no obvious deactivation under simulated emission conditions. The presence of O-2 (5%) reduced N2O conversion only to a small extent, whereas NO (1000 ppm) promoted the N2O decomposition over Fe-beta-80 degrees C. (c) 2013 Curtin University of Technology and John Wiley & Sons, Ltd.