铜铈掺杂六铝酸盐的脱硝性能

用共沉淀法制备用于脱除NO的六铝酸盐催化剂LaMxAl12-xO19(M =Cu,Ce,CuCe).用XRD、H2-TPR和BET对催化剂进行了结构和物性表征.用微型催化反应装置考察了催化剂在CO选择性催化还原NO中的活性.结果表明,Cu离子易于进入六铝酸盐晶格内,形成完整的六铝酸盐结构.Ce离子不易于进入六铝酸盐晶格内,主要以CeO2的形式存在.在CO+ NO条件下,3种催化剂都表现出较好的脱硝活性,LaCuCeAl10O19中由于Cu离子与Ce离子间产生协同作用,该催化剂的脱硝活性有所增加.加入SO2后,3种催化剂都有不同程度的失活现象发生,其中LaCuAl11O19催化剂受SO2中毒影响最严重,LaCuCeAl10O19催化剂的脱硝活性在三者中最好.

Denitrification performance of Cu and Ce doped hexaaluminate catalysts

Hexaaluminate catalysts LaM_xAl_12-xO₁₉ (M=Cu, Ce, CuCe) for NO removal were prepared by the co-precipitation method. The catalysts were characterized by the means of XRD, H₂-TPR and BET. The catalyst efficiency for selective catalytic reduction of NO by CO was evaluated in a catalytic microreactor. The results show that Cu ions can easily enter the hexaaluminate crystal lattice to form a good hexaaluminate phase. Ce ions are hard to enter hexaaluminate skeleton, exist mainly in the form of CeO₂. Under the condition of CO+NO, all of the three catalysts have a good denitrification activity. Due to the synergistic effect between Cu ions and Ce ions, catalyst LaCuCeAl₁₀O₁₉ has a better denitrification activity. With the introduction of SO₂, the denitrification activities of all the three catalysts decline to different levels. Catalyst LaCuAl₁₁O₁₉ is poisoned by SO₂ most seriously, while catalyst LaCuCeAl₁₀O₁₉ has the best denitrification activity among them.