Al^(3+)掺入对CeO_2(ZrO_2)/TiO_2催化剂脱硝性能的影响

Influence of Al^(3+) on the performance of CeO_2(ZrO_2)/TiO_2 for selective catalytic reduction of NO

采用溶胶-凝胶法制备Al ^(3+)掺杂CeO_2(ZrO_2)/TiO_2催化剂,研究了Al ^(3+)掺入对CeO_2(ZrO_2)/TiO_2催化剂脱硝性能的影响。采用X射线衍射、氮气吸附脱附、氨气程序升温吸附、氢气程序升温还原以及荧光光谱等表征技术对催化剂进行表征。结果表明:Al ^(3+)的掺入有利于抑制TiO2从无定型相向锐钛矿相转变,增强了催化剂的储释氧性能,提高了催化剂的强酸酸量和缺陷浓度。强酸酸量和缺陷浓度的提高有利于反应气体的吸附;储释氧性能的增强,吸附的NO物种被氧化的速率加快,有利于催化反应的进行。因此,适量Al ^(3+)的掺入会明显提升CeO_2(ZrO_2)/TiO_2催化剂的高温脱硝活性,拓宽活性温度窗口。71400h-1条件下0.8Al-CZT催化剂在330℃达到最高活性(98.9%)且在400℃脱硝活性依然能够维持90.8%。

A series of CeO2（ZrO2）/TiO2 catalysts were modified with Al 3＋using a sol-gel method.The effect of Al 3＋on the catalytic performance of CeO2（ZrO2）/TiO2 for the selective catalytic reduction（SCR）of NO with NH3 was investigated.The catalysts were characterized by XRD,N2-BET,NH3-TPD,H2-TPR and PL spectra,respectively.Results showed that the addition of Al 3＋could inhibit the transformation of TiO2 from amorphous phase to anatase phase.In addition,Al 3＋ions could increase the defects species concentration and the amount of strong acid sites,which was beneficial for the adsorption of reaction gas.The enhancement of oxygen storage capacity was good for catalytic activity.Therefore,the additions of Al 3＋improved catalytic activity at the high temperature and broadened the active temperature window while the amount was appropriate.Under GHSV was 71400 h-1,0.8 Al-CZT obtained the maximum activity（98.9%）at 330℃ and maintained 90.8% NO conversion at 400℃.