Preparation and Application of Nano Ce-Zr Mixed Oxides Supported H3PW12O40 in Nitrogen Oxide Capture and Decomposition

摘要

In this study, nano Ce-Zr mixed oxides (CeZrO) were prepared, and XRD, BET surface areas, TEM and TPD-MS were employed for characterization and mechanism analysis. CeZrO was initially used as support for solid tungstophosphoric acid (H_3PW_(12)O_(40) or HPW) and was found to have promotion effect on the adsorption and decomposition of NOx. After loading with HPW, the NO_X adsorption efficiency increased, and the highest efficiency of HPW/CeZrO was 98%, much higher than that of pure HPW (ca. 60%). With the increase of HPW loading, the NO_X adsorption efficiency tended to reach a peak value before dropping down. The mechanical grinding method was much more suitable than the incipient impregnation method for CeZrO to load HPW. Furthermore, the adsorbed NO_X was found to decompose into N_2, O_2 and N_2O, and yields of N_2 of 29.7% for HPW/CeZrO was obtained upon heating at a ramp rate of 50 °C/min.