Kinetics and mechanism of the N2O reduction by NH3 on a Fe-zeolite-beta catalyst

被引:82
作者
Coq, B
Mauvezin, M
Delahay, G
Kieger, S
机构
[1] Grande Paroisse, F-92062 Paris La Defense, France
[2] ENSCM, Lab Mat Catalyt & Catalyse Chim Organ, CNRS, UMR 5618, F-34296 Montpellier 5, France
关键词
nitrous oxide; ammonia; Fe-zeolite; reduction; mechanism;
D O I
10.1006/jcat.2000.2980
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
In the context of decreasing the emissions of greenhouse gases, a Fe-exchanged zeolite-beta (Fe-BEA) catalyst is shown to be very active in the reduction of N2O by NH3 in the presence of O-2. The temperature at which 50% N2O conversion is obtained is lower by ca. 80 K compared to its catalytic decomposition in the absence of NH3. TPR, TPO, and TPD experiments after treatments in various atmospheres provide evidence that the reaction involves the redox cycle Fe-III <->Fe-II where the Fem active species are Fe oxocations of low nuclearity. N2O decomposes into O* surface species on specific reduced Fe sites with the concurrent release of N-2; these species do not compete with O* coming from O-2 for their removal by NH3. In the absence of O-2, catalytic experiments with (N2O)-N-14 and (NH3)-N-15 show that: (1) N-2 is mainly formed from (NN)-N-14-N-14-O Splitting to yield N-14(2), the O* species being in turn removed by (NH3)-N-15 to give N-15(2); (2) some N-14-(NO)-N-14 bond splitting occurs, which leads to (NN)-N-14-N-15 after reaction of (NO)-N-14* and (NH3)-N-15 through a classical SCR mechanism. The Fe active species in the N-NO splitting are inhibited in the presence of O-2. The kinetics of N2O reduction by NH3 obeys a Mars and van Krevelen oxide-reduction mechanism modified with an inhibiting term of NH3. (C) 2000 Academic Press.
引用
收藏
页码:298 / 303
页数:6
相关论文
共 24 条
  • [1] Bosch H., 1986, CATAL TODAY, V2, P369, DOI DOI 10.1016/0920-5861(88)80002-6
  • [2] Selective catalytic reduction of N2O in industrial emissions containing O2, H2O and SO2:: behavior of Fe/ZSM-5 catalysts
    Centi, G
    Vazzana, F
    [J]. CATALYSIS TODAY, 1999, 53 (04) : 683 - 693
  • [3] Activity and durability of Fe/ZSM-5 catalysts for lean burn NOx reduction in the presence of water vapor
    Chen, HY
    Sachtler, WMH
    [J]. CATALYSIS TODAY, 1998, 42 (1-2) : 73 - 83
  • [4] The simultaneous catalytic reduction of NO and N2O by NH3 using an Fe-zeolite-beta catalyst
    Coq, B
    Mauvezin, M
    Delahay, G
    Butet, JB
    Kieger, S
    [J]. APPLIED CATALYSIS B-ENVIRONMENTAL, 2000, 27 (03) : 193 - 198
  • [5] Isothermal oscillations during N2O decomposition over Fe/ZSM-5:: effect of H2O vapor
    El-Malki, EM
    van Santen, RA
    Sachtler, WMH
    [J]. MICROPOROUS AND MESOPOROUS MATERIALS, 2000, 35-6 : 235 - 244
  • [6] REDOX CATALYSIS IN ZEOLITES - INVESTIGATION OF THE BEHAVIOR OF IRON-EXCHANGED MORDENITE TOWARD CARBON-MONOXIDE REDUCTION
    FANG, SM
    PETUNCHI, J
    LEGLISE, J
    MILLMAN, WS
    HALL, WK
    [J]. JOURNAL OF CATALYSIS, 1985, 96 (01) : 182 - 188
  • [7] Forzatti P, 1996, HETEROGEN CHEM REV, V3, P33, DOI 10.1002/(SICI)1234-985X(199603)3:1<33::AID-HCR54>3.0.CO
  • [8] 2-R
  • [9] DECOMPOSITION OF NITROUS-OXIDE ON FEY ZEOLITE
    FU, CM
    KORCHAK, VN
    HALL, WK
    [J]. JOURNAL OF CATALYSIS, 1981, 68 (01) : 166 - 171
  • [10] Kapteijn F, 1996, APPL CATAL B-ENVIRON, V9, P25