摘要
利用共沉淀法制备了铁铈催化剂,考察添加钛、锆、钨和钼对其SCR脱硝的改性规律。结果表明,钨和钼的添加提高了铁铈催化剂高温脱硝性能,却使其低温活性有所降低;钛的添加对铁铈催化剂脱硝性能具有促进作用,尤其提高了其低温活性,并拓宽了其完全转化温度窗口,为最佳改性物。当钛的物质的量比逐渐由0.10增至0.40,铁铈钛催化剂低温脱硝效率先增大后减小,但其高温脱硝效率逐渐增大至100%,钛的最佳物质的量比为0.15。XRD和N2吸附分析结果表明,钛能优化铁铈催化剂的孔隙结构,增大其比表面积和比孔容,细化其孔径,并与催化剂中铁、铈氧化物形成良好的固溶体,从而提高了铁铈催化剂的SCR脱硝性能。Fe0.8Ce0.05Ti0.15Oz催化剂在150～400℃取得了高于90%的NOx转化率。
A series of iron-cerium mixed oxide catalysts modified titanium, zirconium, tungsten and molybdenum were prepared by co-precipitation. The selective catalytic reduction of NO2 with NH3 （NH3-SCR） activity of the catalysts were carried out in a fixed-bed quartz tube reactor. The research results indicated that the addition of tungsten and molybdenum could increase the high-temperature NH3-SCR activity of the iron-cerium mixed oxide catalysts, but decreased its low-temperature NH3-SCR activity. Titanium could improve the NH3- SCR activity of the iron-cerium mixed oxide catalyst within the range of reaction temperature, especially at low- temperature. Titanium was the most suitable assistant. When increasing the molar fraction of titanium from 0.10 to 0.40, the low-temperature NH3-SCR activity of iron-cerium-titanium mixed oxide catalysts firstly increased and then decreased while the high-temperature activity gradually increased to 100%, and the optimum molar fraction of titanium was 0.15. The results of X-ray diffraction（XRD） and N2 adsorption isotherms showed that the addition of titanium could optimize the pore structure of iron-cerium mixed oxide catalyst, and increased the BET surface and the pore volume of the iron-cerium mixed oxide catalyst, meanwhile refined its pore size. At the some cases, titanium could react with iron oxide and cerium oxide within the iron-cerium mixed oxide catalyst to form the solid solution. Therefore, the addition of titanium could enhance the NH3-SCR activity of iron-cerium mixed oxide catalyst. Under the condition of the test, more than 90% of NOx conversion could be achieved over Fe0.8 Ceo. 05 Ti0.15 Oz catalyst at the temperature range of 150 ~ 400 ~（2.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2013年第3期361-367,共7页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(51276101)
山东省自然科学基金(ZR2012EEM013)
关键词
铁铈复合氧化物催化剂
选择性催化还原脱硝
NOx
钛
改性
iron-cerium 1nixed oxide catalyst
selective catalytic reduction （SCR） of NO
NOx
titanium
modification
