铁基氧化物催化剂用于NH3选择性催化还原NO的研究.doc

铁基氧化物催化剂用于NH3选择性催化还原NO的研究.docABSTRACT
NOx is one of the pollutants causing the greenhouse effect, ac id rain and ozone
dep letio n, and has had a serio us imp act on eco no mic de ve lop me nt, eco lo gical balance
and peop le' s lives. Cur re ntly se lec tive ca ta lytic red uctio n of NO with (NH3-SCR) is
the most effective technique for the remo val of N itrogen Oxide(NOx,x=1,2). The
co mmercial ca ta lyst is mainly va nad ium- ba sed ca ta lyst (V2O5-WO3(MoO3)/TiO2).
Altho ugh the catalyst has been ind ustr ia lized for many years, there are some prob le ms:
narrow te mper ature windows, toxicity of vanadium pent-oxide to e nviro nme nt and
human hea lt h, and higher activity for oxidation of SO2 to SO3.
In this paper, no n-to xic to the e nviro nme nt and lo w-cost iron-based o xide
catalysts were prepared for selective ca ta lytic red uctio n of NO by ammonia. By
adjusting the co nte nt of Ce and W, the catalysts with best catalytic perfo rmance were
sa mp les were characterized by SEM, BET, XRD, NH3-TPD and
H2-TPR to investigage the structural feature. The e ffe ct of ca lc inatio n temperature and
catalytic reaction co nd itio ns on the ca ta lytic activity was stud ied.
(1) A series of FeaWbOx catalysts were prepared by co-precipitation and the
results showed that the catalyst with the Fe/W mo lar ra tio of 4/1 e xhib ited the best
catalytic activity with abo ve 90% NO conve rs io n in the te mperature ra nge from
250oC to 400oC unde r the space ve loc ity of 75,000 h-1. The Fe4WOx catalyst a lso
showed high to lera nce to SO2 and H2O in the test co nd itio n. The c ha racte riza tio n
result sho wed that the strong interaction between Fe and W, the la rge specific surface,
and the strong acidity were the main reasons for the iron-tungsten mixed o xide
catalyst to a cq uire the high catalytic activity.
(2) A serie s of Fe4WCeyOx catalysts were prepared by co-precipitation and the
results showed that Fe4WCeOx(y=1) catalyst had best catalyst per for m