An investigation of the NO/H2/O2 reaction on noble-metal catalysts at low temperatures under lean-burn conditions

被引:172
作者
Burch, R [1 ]
Coleman, MD [1 ]
机构
[1] Univ Reading, Dept Chem, Ctr Catalysis Res, Reading RG6 6AD, Berks, England
关键词
Pt catalysts; NO reduction by hydrogen; lean-burn; N2O selectivity;
D O I
10.1016/S0926-3373(99)00073-9
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
The NO/H-2/O-2 reaction has been studied under lean-burn conditions at low temperatures. Maxima in the NO conversions have been observed for a Pt/Al2O3 catalyst at 140 degrees C (50% conversion) and for a 1% Pt/SiO2 catalyst at 90 degrees C (75% conversion). The selectivity to N2O is sensitive to the reaction conditions and decreases as the temperature is raised. Addition of water has a noticeable effect on both the activity and the selectivity for the NO reduction reaction, with N-2 formation being significantly decreased when water is introduced into the reaction mixture. The effect of varying the NO and H-2 concentrations has been examined. In general, increasing the NO concentration lowers the activity, whereas increasing the H-2 concentration increases the activity for NO reduction. The effect of these concentration changes on the selectivity to N2O is complex. (C) 1999 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:115 / 121
页数:7
相关论文
共 31 条
[1]   A comparison of the selective catalytic reduction of NOx over Al2O3 and sulphated Al2O3 using CH3OH and C3H8 as reductants [J].
Burch, R ;
Halpin, E ;
Sullivan, JA .
APPLIED CATALYSIS B-ENVIRONMENTAL, 1998, 17 (1-2) :115-129
[2]   Particle size and support effects on the activity and deactivation of Pt-based catalysts for the reduction of NO by n-octane under lean-burn conditions [J].
Burch, R ;
Fornasiero, P ;
Southward, BWL .
CHEMICAL COMMUNICATIONS, 1998, (05) :625-626
[3]   Mechanistic considerations for the reduction of NOx over Pt/Al2O3 and Al2O3 catalysts under lean-burn conditions [J].
Burch, R ;
Sullivan, JA ;
Watling, TC .
CATALYSIS TODAY, 1998, 42 (1-2) :13-23
[4]   The effect of promoters on Pt/Al2O3 catalysts for the reduction of NO by C3H6 under lean-burn conditions [J].
Burch, R ;
Watling, TC .
APPLIED CATALYSIS B-ENVIRONMENTAL, 1997, 11 (02) :207-216
[5]   MECHANISM OF THE SELECTIVE REDUCTION OF NITROGEN MONOXIDE ON PLATINUM-BASED CATALYSTS IN THE PRESENCE OF EXCESS OXYGEN [J].
BURCH, R ;
MILLINGTON, PJ ;
WALKER, AP .
APPLIED CATALYSIS B-ENVIRONMENTAL, 1994, 4 (01) :65-94
[6]   An investigation of the deactivation of Rh/alumina catalysts under strong oxidising conditions [J].
Burch, R ;
Loader, PK ;
Cruise, NA .
APPLIED CATALYSIS A-GENERAL, 1996, 147 (02) :375-394
[7]   A method for obtaining stable, high activity for NOx reduction at low temperatures [J].
Burch, R ;
Fornasiero, P ;
Southward, BWL .
CHEMICAL COMMUNICATIONS, 1998, (07) :739-740
[8]   AN INVESTIGATION OF THE MECHANISM OF THE SELECTIVE CATALYTIC REDUCTION OF NO ON VARIOUS METAL/ZSM-5 CATALYSTS - REACTIONS OF H2/NO MIXTURES [J].
BURCH, R ;
SCIRE, S .
CATALYSIS LETTERS, 1994, 27 (1-2) :177-186
[9]   SELECTIVE REDUCTION OF NITROGEN-OXIDES BY HYDROCARBONS UNDER LEAN-BURN CONDITIONS USING SUPPORTED PLATINUM-GROUP METAL-CATALYSTS [J].
BURCH, R ;
MILLINGTON, PJ .
CATALYSIS TODAY, 1995, 26 (02) :185-206
[10]  
DUMPELMANN R, 1994, 3 ICC AUT POL CONTR, V2, P13