| 초록 |
NOx reduction to N2 by C3H6 was investigated on various copper alumina catalysts prepared by precipitation method. It was found that the catalyst preparation method as well as the copper content exerts a significant influence on catalyst activity. The catalysts were prepared using a mixture of 1M Na2CO3 and 2M NaOH as precipitating agent. The prepared catalysts were characterized by XRD, DTA, TGA, FT-IR, BET-SA, XPS, H2-TPR and SEM. From the DTA analysis it was found that the loss of water and CO2 observed at 114 to 390 °C and total weight loss (TGA) at around 600 °C. The results of XPS show that the Cu-Al (30-70) catalysts calcined at 600 °C possess highly dispersed surface and bulk CuO and CuAl2O4 phases. The presence of Cu2+ phase was also confirmed from the TPR and XPS. A high conversion (70%) of NOx to N2 was obtained by Cu-Al (30-70) catalyst at 300 °C in presence of 600 ppm NOx+ 600 ppm C3H6+ 8 vol% O2. The order of NOx to N2 conversion as follows Cu-Al (30-70) ＞ Cu-Al (20-80) ＞ Cu-Al (40-60) ＞ Cu-Al (10-90) ＞ Cu (70-30). Based on the in-situ DRIFT specta, different reaction intermediates R-NO, -COO- and –NO2 were formed on various catalysts with difference in intensities. Also studied the formation of different intermediates with difference in intensities upon increase of temperature of Cu-Al (30-70) catalyst. |
