Hydrogen as a remedy for the detrimental effect of aromatic and cyclic compounds on the HC-SCR over Ag/alumina

Arve, Kalle; Backman, Henrik; Klingstedt, Fredrik; Eränen, Kari; Murzin, Dmitry Yu.

doi:10.1016/j.apcatb.2005.10.036

Cited by 42 publications

(30 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At 250°C the reaction order in H 2 is approximately 0.35 and increases to *0.45 when the C 6 H 14 concentration increases to 280 ppm. These results are in a good agreement with the data reported by Arve [9]. Above 370-390°C the hydrogen effect seems to be minor and the temperature dependences of NO x conversion in the course of SCR with and without H 2 -cofeeding are essentially identical (Fig.…”

Section: Resultssupporting

confidence: 94%

“…However, in most investigations of the hydrogen effect, relatively high H 2 concentrations have been used (e.g., H 2 concentration of 1000-4000 ppm [3], 5000 ppm [4], 500-7200 ppm [5,6], 5000 ppm: 1% [7], 1% [8,9]). Therefore, experimental data on Ag/Al 2 O 3 performance and a possible reaction mechanism within a practical range of H 2 concentrations are scarce.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Two Reaction Pathways in the Selective Catalytic Reduction of NO x by C6H14 Over Ag–Al2O3 with H2 Co-Feeding

et al. 2009

View full text Add to dashboard Cite

The NO x reduction with n-C 6 H 14 was studied over a 3% Ag/Al 2 O 3 catalyst in the presence of hydrogen. The catalyst performance was evaluated by varying the H 2 concentration from 0 to 1600 ppm and by comparing the results with blank runs in which an empty reactor with no catalyst was used. Two distinct reaction pathways were revealed: one at low-temperature (T react \ 370°C) and another one at high-temperature (T react [ 370-390°C). Co-feeding of H 2 promotes the reaction within the 150-360°C interval. The high-temperature pathway (T react [ 370-390°C) seems to be almost independent of hydrogen co-feeding. The homogeneous gas-phase NO x oxidation initiated by NO presumably plays an important role in this high-temperature pathway.

show abstract

Section: Resultssupporting

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Two Reaction Pathways in the Selective Catalytic Reduction of NO x by C6H14 Over Ag–Al2O3 with H2 Co-Feeding

et al. 2009

View full text Add to dashboard Cite

show abstract

“…GC-MS analyses revealed that when n-octane was used as the reducing agent, a variety of amines, aldehydes and alcohols were detected between 150-300°C, while above 300°C mainly oxygenated species were observed [18]. Era¨nen et al [19] have also shown that species like R-NH 2 , NH 3 , R-NCO and R-CN are formed over the Ag/alumina resulting in N 2 formation in the gas phase behind the catalyst.…”

Section: Methyl and Ethyl Laurate-scrmentioning

confidence: 95%

Selective catalytic reduction of NO x over Ag/Al2O3 using various bio-diesels as reducing agents

et al. 2007

View full text Add to dashboard Cite

The effect of bio-diesel compounds (vegetable methyl and ethyl laurate and hexadecane) as reducing agents on the selective catalytic reduction of NO x over a 2 wt.% Ag/Al 2 O 3 was investigated. These components were found to have a two-fold effect on the SCR over Ag/Al 2 O 3 . First, the reduction activity below 400°C was higher with bio-diesel than with n-octane, which is a representative compound for fossil fuels. This effect is attributed to the presence of the ester group in these molecules. However, the conversion above 400°C decreased sharply and was considerable lower than with n-octane. The most interesting observation was found when the reduction efficiency of bio-diesel components was tested in the presence of hydrogen. The well known low temperature boosting effect of hydrogen was visible not only at lower temperatures, but also above 400°C. Mechanistically the observation is extremely interesting and indicates that hydrogen effect cannot directly be connected to reduction of surface nitrates, which can be operative only at low temperature domain.

show abstract

“…℃ 16,18 Additionally, when H 2 levels were higher than 5%, NO x levels can be reduced at low temperatures (about 150 ). ℃…”

Section: Introductionmentioning

confidence: 98%

NO_x Reduction Characteristics for Different Composition Ratios of Pt/Al₂O₃, Rh/Al₂O₃ Catalyst Mixtures Using Model Gas as Reformates

Chung

Lim

et al. 2010

Chin. J. Chem.

View full text Add to dashboard Cite

This study investigated the selective catalytic reduction (SCR) of nitrogen oxides (NO x ) with hydrocarbon in the presence of excess oxygen using various composition ratios of Pt/Al 2 O 3 , Rh/Al 2 O 3 catalyst mixtures. The composition ratios were 1 1, 1 2, 2 ∶ ∶ ∶1, 1∶3 and 3∶1 of 1 wt% Pt/Al 2 O 3 and Rh/Al 2 O 3 , which are known to exhibit efficient NO x reduction at low and high temperatures among the noble metal catalysts. Experiments conducted on a single reductant revealed that more efficient NO x conversion could be obtained when Pt/Al 2 O 3 and Rh/Al 2 O 3 were mixed at a ratio of 3 1, rather than 1 ∶ ∶1 or 1∶3. In a single reductant condition, C 3 H 6 800 ppm (2400 ppmC 1 ) and 400 ppm (1200 ppmC 1 ) exhibited 50% and 38% NO x conversion efficiency at 200 , respectively. However, NO ℃

show abstract

Hydrogen as a remedy for the detrimental effect of aromatic and cyclic compounds on the HC-SCR over Ag/alumina

Cited by 42 publications

References 23 publications

Two Reaction Pathways in the Selective Catalytic Reduction of NO x by C6H14 Over Ag–Al2O3 with H2 Co-Feeding

Two Reaction Pathways in the Selective Catalytic Reduction of NO x by C6H14 Over Ag–Al2O3 with H2 Co-Feeding

Selective catalytic reduction of NO x over Ag/Al2O3 using various bio-diesels as reducing agents

NO_x Reduction Characteristics for Different Composition Ratios of Pt/Al₂O₃, Rh/Al₂O₃ Catalyst Mixtures Using Model Gas as Reformates

Contact Info

Product

Resources

About

Hydrogen as a remedy for the detrimental effect of aromatic and cyclic compounds on the HC-SCR over Ag/alumina

Cited by 42 publications

References 23 publications

Two Reaction Pathways in the Selective Catalytic Reduction of NO x by C6H14 Over Ag–Al2O3 with H2 Co-Feeding

Two Reaction Pathways in the Selective Catalytic Reduction of NO x by C6H14 Over Ag–Al2O3 with H2 Co-Feeding

Selective catalytic reduction of NO x over Ag/Al2O3 using various bio-diesels as reducing agents

NOx Reduction Characteristics for Different Composition Ratios of Pt/Al2O3, Rh/Al2O3 Catalyst Mixtures Using Model Gas as Reformates

Contact Info

Product

Resources

About

NO_x Reduction Characteristics for Different Composition Ratios of Pt/Al₂O₃, Rh/Al₂O₃ Catalyst Mixtures Using Model Gas as Reformates