An Investigation of Promoter Effects in the Reduction of NO by H2 under Lean-Burn Conditions

Burch, Robbie; Coleman, Marc D.

doi:10.1006/jcat.2002.3596

Cited by 102 publications

(49 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A drop of the ethanol suspension was placed on the carbon coated copper grid and the ethanol was then allowed to evaporate in ambient conditions. 4 ] 2+ ions has not been observed when silica gel (Grace) was used in place of Na-magadiite, under similar intercalation reaction conditions. The amount of Pt loaded on silica gel was considerably lower (1.3 wt.%; not shown) than the amount of Pt loaded on Na-magadiite (22.2 wt.%).…”

Section: Characterisationmentioning

confidence: 95%

“…The measurements were conducted from ambient temperature to 1000 °C at a heating rate of 10 °C min -1 in air. 4 ] 2+ ions at room temperature followed by calcination at 600 °C in air.…”

Section: Characterisationmentioning

confidence: 99%

“…Silica-supported Pt catalysts are of considerable interest because of their potential applications in a large number of industrially important chemical reactions such as oxidation, hydrogenation, cracking, hydroisomerisation and NO x reduction reactions [1][2][3][4]. For most of these potential catalytic applications, highly dispersed and thermally stable Pt particles or nano-clusters are necessary for the better performance of the catalysts.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Intercalation of [Pt(NH3)4]2+ ions into layered sodium silicate magadiite: a useful method to enhance their stabilisation in a highly dispersed state

Schwieger

Selvam

Gravenhorst

et al. 2004

Journal of Physics and Chemistry of Solids

View full text Add to dashboard Cite

Al-free layered sodium silicate magadiite has been used as the host material for the stabilisation of [Pt(NH3)4] 2+ ions via intercalation and/or ionexchange reactions. The stabilisation of Pt(NH3)4] 2+ ions in between the layers of Na-magadiite was confirmed by thermogravimetric analysis (TGA), where increased decomposition temperatures were observed for the intercalated materials. The intercalation behaviour of Na-magadiite was evident from the significant uptake of Pt ions (22.2 wt.%). When silica gel was used as the host matrix, negligible uptake of Pt ions (1.3 wt.%) was noticed. The X-ray diffraction (XRD) measurements revealed no appreciable change in the basal spacing of the intercalated materials. Nevertheless, the decrease in the intensity of the 001 peak with increasing Pt loadings (from 13.0 to 22.2 wt.%) substantiated the intercalation of [Pt(NH3)4] 2+ ions within the interlayer spaces of Na-magadiite. The transmission electron microscopy (TEM) studies of the intercalated materials revealed that [Pt(NH3)4] 2+ ions were homogeneously intercalated in the magadiite matrix, ranging from 2-3 nm. Subsequent calcination of the intercalated materials at 600 °C in air led to the formation of Pt nanoparticles supported on silica. The results of XRD and TEM indicated that Pt nanoparticles were highly dispersed on the silica support and were in the range of 5-12 nm. Moreover, chemical analyses confirmed the high loading of Pt on silica in agreement with the TGA results.

show abstract

Section: Characterisationmentioning

confidence: 95%

“…The measurements were conducted from ambient temperature to 1000 °C at a heating rate of 10 °C min -1 in air. 4 ] 2+ ions at room temperature followed by calcination at 600 °C in air.…”

Section: Characterisationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Intercalation of [Pt(NH3)4]2+ ions into layered sodium silicate magadiite: a useful method to enhance their stabilisation in a highly dispersed state

Schwieger

Selvam

Gravenhorst

et al. 2004

Journal of Physics and Chemistry of Solids

View full text Add to dashboard Cite

show abstract

“…Significant attention has been given to the development of selective catalytic reduction (SCR) of NO x using H 2 [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], CO [19][20][21], or a mixture of H 2 /CO [22][23][24][25][26][27][28][29][30][31][32][33] as reductant. Catalysts using H 2 and/or CO have the advantage of lowtemperature DeNO x activity, and the reductants could be produced using an on-board fuel reformer, thus eliminating the need of carrying any additional reductant.…”

Section: Introductionmentioning

confidence: 99%

Influence of Supports on Pd Catalysts for the Selective Catalytic Reduction of NOx with H2 and CO

Caravaggio

Nossova

Burich

2015

Emiss. Control Sci. Technol.

View full text Add to dashboard Cite

A major concern of current commercial catalysts for the selective catalytic reduction (SCR) of nitrogen oxides (NO x ) (DeNO x ) is the lack of sufficient catalytic activity at low temperatures (below 200°C) that typically occur during cold start and urban driving conditions. To address this issue, a study was undertaken to develop an (H 2 + CO)-SCR Pd-based catalyst to obtain high DeNO x activity in this low-temperature range. A series of catalysts with Pd loaded on supports containing various amounts of γ-alumina (γ-Al 2 O 3 ) (0-65 wt%), CBV-2314 (15-100 wt%), and TiO 2 (0-20 wt%) were tested for DeNO x activity and aging in a catalyst testing unit (CTU). The results showed that each component in the support played a role in the NO x conversion, depending on the temperature. Catalysts with Pd supported on {[γ-Al 2 O 3 (60 wt%)+CBV-2314 (20 wt%)]-TiO 2 (20 wt%)} achieved the best overall DeNO x activity. Catalysts with various Pd loadings (0.05 wt% to 0.5 wt%) were prepared with a {[γ-Al 2 O 3 (60 wt%)+CBV-2314 (20 wt%)]−TiO 2 (20 wt%)} support. The catalysts loaded with 0.05 wt% and 0.2 wt% Pd demonstrated the best overall DeNO x activity (up to 90 % NO x conversion starting at 150°C). These catalysts were subjected to an accelerated aging regime. Based on the aging studies, the 0.2 wt% Pd/{[γ-Al 2 O 3 (60 wt%)+CBV-2314 (20 wt%)]− TiO 2 (20 wt%)} composition was the most active and stable catalyst.

show abstract

“…The addition of hydrogen-rich reformate to aftertreatment systems is also beneficial as it has been shown that hydrogen can improve the performance of catalytic aftertreatment devices in reducing emissions either directly [13][14][15][16] or by increasing the effectiveness of other agents in reducing emissions [17][18][19][20]. However, the demands made of a reformer in an REGR system [9] can be quite different to those required for promoting aftertreatment.…”

Section: Introductionmentioning

confidence: 99%

Diesel exhaust-gas reforming for H2 addition to an aftertreatment unit

Abu-Jrai¹,

Tsolakis²,

Theinnoi³

et al. 2008

Chemical Engineering Journal

View full text Add to dashboard Cite

The work described in this paper has been undertaken as part of the design of an integrated system comprising a diesel engine, an exhaust-gas fuel reformer and a NO x aftertreatment unit. The exhaustgas reformer is used to provide hydrogen-rich reformate to the NO x aftertreatment unit, containing a hydrocarbon-SCR catalyst, in order to improve its NO x reduction activity at low exhaust-gas temperatures. The reformer configuration and operating parameters have been examined in order to optimise the performance of the hydrocarbon-SCR catalyst, which is promoted by the presence of H 2 but inhibited by CO. The length of the catalyst bed inside the reformer is a key factor in determining the extent to which the water-gas shift reaction can contribute to the reforming process, and therefore strongly influences the proportions of CO and H 2 in the reformate. However, it is also necessary for the reactant ratios at the reformer inlet to be controlled in response to changes in the engine operating conditions. In practice this means that the rate of fuel addition to the reformer needs to be optimised for different exhaust gas compositions and space velocities.

show abstract

An Investigation of Promoter Effects in the Reduction of NO by H2 under Lean-Burn Conditions

Cited by 102 publications

References 57 publications

Intercalation of [Pt(NH3)4]2+ ions into layered sodium silicate magadiite: a useful method to enhance their stabilisation in a highly dispersed state

Intercalation of [Pt(NH3)4]2+ ions into layered sodium silicate magadiite: a useful method to enhance their stabilisation in a highly dispersed state

Influence of Supports on Pd Catalysts for the Selective Catalytic Reduction of NOx with H2 and CO

Diesel exhaust-gas reforming for H2 addition to an aftertreatment unit

Contact Info

Product

Resources

About