CAJ | 학술논문

采用溶胶凝胶法制备了低温脱硝活性良好的Mn-Ce-Zr/γ-Al2O3催化剂。催化剂在150℃下达到接近70%的脱硝效率并在250~300℃下升高到95%左右。空速和SO2/H2O 性能影响实验表明催化剂具有较好的空速变化适应能力和抗 SO2/H2O 中毒性能。NH3和 NO 氧化性能实验在固定床上进行。结果发现 NH3在300℃以上会逐渐被氧化为NO；而NO在250~300℃下容易被氧化为NO2，这有利于选择性催化还原反应的进行。利用多种表征手段，如N2吸附脱附、X射线衍射、H2程序升温还原和程序升温脱附，对催化剂进行了表征。结果表明Zr可以掺杂进入CeO2微晶晶格内并形成了固溶体结构，这可以提高催化剂的比表面积和孔结构参数。程序升温脱附结果表明 NH3主要吸附在催化剂的不稳定酸性位上，而NO吸附后可以亚硝酸盐、不稳定和稳定硝酸盐等多种形式存在，这有利于促进低温选择性催化还原反应的进行。
채용용효응효법제비료저온탈초활성량호적Mn-Ce-Zr/γ-Al2O3최화제。최화제재150℃하체도접근70%적탈초효솔병재250~300℃하승고도95%좌우。공속화SO2/H2O 성능영향실험표명최화제구유교호적공속변화괄응능력화항 SO2/H2O 중독성능。NH3화 NO 양화성능실험재고정상상진행。결과발현 NH3재300℃이상회축점피양화위NO；이NO재250~300℃하용역피양화위NO2，저유리우선택성최화환원반응적진행。이용다충표정수단，여N2흡부탈부、X사선연사、H2정서승온환원화정서승온탈부，대최화제진행료표정。결과표명Zr가이참잡진입CeO2미정정격내병형성료고용체결구，저가이제고최화제적비표면적화공결구삼수。정서승온탈부결과표명 NH3주요흡부재최화제적불은정산성위상，이NO흡부후가이아초산염、불은정화은정초산염등다충형식존재，저유리우촉진저온선택성최화환원반응적진행。
The Mn-Ce-Zr/γ-Al2O3 catalyst with high selective catalytic reduction (SCR) activity at low temperature was prepared by the sol-gel method. The NO conversion reaches 70% at 150℃ and then increases to 95% at 250~ 300℃. The catalyst can also be well-behaved under high space velocity and in the presence of SO2 and H2O. NH3 and NO oxidation performance was tested on the fixed bed. It shows that NH3 can be oxidized to NO at high temperature, while NO is easy to be oxidized to NO2 at 250~300℃, which is beneficial for the proceeding of SCR reactions. Several characterization methods, such as N2 adsorption-desorption, X-ray diffraction (XRD), H2-temperature programmed reduction (H2-TPR) and temperature programmed desorption (TPD) were adopted. It shows that Zr can be incorporated into the CeO2 crystal lattice and form the solid solution, resulting that the BET surface area and pore volume of this catalyst increases obviously. The results of TPD indicate that NH3 is mainly adsorbed on the weak acid sites, and NO can be adsorbed as the nitrite, unstable and stable nitrate species, which is in favor of the low-temperature SCR reaction proceedings.