A novel dual layer SCR catalyst with a broad temperature window for the control of NO  emission from diesel bus

Qi, Feihong; Xiong, Shangchao; Liao, Yong; Dang, Hao; Yang, Shijian

doi:10.1016/j.catcom.2015.03.002

Cited by 10 publications

(6 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Meanwhile, NH 2 on the surface can be deeply oxidized to gaseous NO at high temperatures (i.e., reaction 7), which was the so-called C−O reaction. 19,36 The formed NO from the C−O reaction can then react with NH 2 to form N 2 (i.e., reaction 6), which was the socalled the selective catalytic oxidation of NH 3 .…”

Section: Resultsmentioning

confidence: 99%

“…At last, NH 2 on the surface reacted with gaseous NO to form N 2 (i.e., reaction ). Meanwhile, NH 2 on the surface can be deeply oxidized to gaseous NO at high temperatures (i.e., reaction ), which was the so-called C–O reaction. , The formed NO from the C–O reaction can then react with NH 2 to form N 2 (i.e., reaction ), which was the so-called the selective catalytic oxidation of NH 3 . NO reduction over Ce/TiO 2 and sulfated Ce/TiO 2 through the Langmuir–Hinshelwood mechanism can be approximately described as follows: ,,, Adsorbed nitrite (including monodentate nitrite over Ce/TiO 2 and nitro over sulfated Ce/TiO 2 ) first reacted with adsorbed NH 3 species to form NH 4 NO 2 , which was then decomposed to H 2 O and N 2 .…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of H₂O and SO₂ on the Selective Catalytic Reduction of NO with NH₃ Over Ce/TiO₂ Catalyst: Mechanism and Kinetic Study

et al. 2016

Self Cite

View full text Add to dashboard Cite

Ce-based catalysts now were regarded as a promising alternative to substitute V2O5/WO3–TiO2 catalyst for the abatement of NO x in the flue gas. However, H2O and SO2 showed a notable effect on NO reduction over Ce based catalysts and the mechanism was not very clear. In this work, the mechanism of H2O and SO2 effect on NO reduction over Ce/TiO2 was studied using the steady state kinetic study and the reaction kinetic parameters were compared. Although H2O and SO2 both showed a promotion on NO reduction over Ce/TiO2 at higher temperatures, their mechanisms were quite different. The effect of SO2 on NO reduction over Ce/TiO2 was mainly attributed to the sulfation. The selective catalytic reduction (SCR) reaction over Ce/TiO2 at higher temperatures was promoted after the sulfation due to the promotion of NH3 adsorption. Meanwhile, the catalytic oxidation of NH3 to NO (i.e., the C–O reaction) over Ce/TiO2 at higher temperatures was suppressed after the sulfation. Therefore, the promotion of NO reduction over Ce/TiO2 at higher temperatures due to the introduction of SO2 was related to not only the inhibition of the C–O reaction but also the promotion of the SCR reaction. However, the SCR reaction over Ce/TiO2 at higher temperatures was restrained in the presence of H2O due to the inhibition of NH3 adsorption and the decrease of oxidation ability. Therefore, the promotion of NO reduction over Ce/TiO2 at higher temperatures due to the presence of H2O was mainly attributed to the inhibition of the C–O reaction.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Effect of H₂O and SO₂ on the Selective Catalytic Reduction of NO with NH₃ Over Ce/TiO₂ Catalyst: Mechanism and Kinetic Study

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…Both the SCR reaction and the NSCR reaction contributed to NO conversion and NH 3 conversion. , Although the C–O reaction contributed to NH 3 conversion, it contributed to NO formation. , Therefore, NH 3 conversion (η NH3 ) and NO x conversion (η NO x ) can be described as follows: where η SCR , η NSCR , and η C–O were the contributions of the SCR reaction, the NSCR reaction, and the C–O reaction, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…Reaction is the deep oxidation of NH to NO, which is the key step of the C–O reaction. The formed NO from Reaction can then react with NH 2 /NH on the surface to N 2 /N 2 O, which is the so-called selective/nonselective catalytic oxidation of NH 3 . , There is generally agreement that NH 3 cannot be directly oxidized to N 2 or N 2 O and the formation of N 2 and N 2 O from NH 3 oxidation are mainly related to Reactions and . − Reaction is the regeneration of V 5+ on V 2 O 5 –WO 3 /TiO 2 .…”

Section: Discussionmentioning

confidence: 99%

Global Kinetic Study of NO Reduction by NH₃ over V₂O₅–WO₃/TiO₂: Relationship between the SCR Performance and the Key Factors

Xiong

Xiao

Liao

et al. 2015

Ind. Eng. Chem. Res.

Self Cite

View full text Add to dashboard Cite

The nonselective catalytic reduction (NSCR) reaction and the catalytic oxidation of NH3 to NO (C–O reaction) simultaneously happened during the selective catalytic reduction (SCR) of NO with NH3 over V2O5–WO3/TiO2, especially at higher temperatures. There was an excellent linear relationship between the SCR reaction rate and gaseous NO concentration, and the intercept and slope can be used to describe the rate constant of NO reduction through the Langmuir–Hinshelwood mechanism and that through the Eley–Rideal mechanism, respectively. However, the NSCR reaction rate was nearly independent of gaseous NO concentration, and the reaction order of the C–O reaction with respect to gaseous NO concentration was much less than zero. According to the kinetic study, the relationship of the SCR performance (i.e., SCR activity and N2 selectivity) with the key factors (for example V2O5 content, H2O effect, and reactant concentration) was built, which can be used to predict the SCR performance.

show abstract

“…Despite the high efficiency of diesel engines, diesel particulate matter (DPM) or simply soot is an unsolicited byproduct emitted by diesel exhaust engines. Soot can not only foul the exhaust system, but also cause severe respiratory hazards such as asthma, bronchitis, and lung cancers when inhaled [1], [2], [4], [5], [6], [7], [8]. Consequently, emission threshold limits have been established and constantly tightened due to the increased emission of DPM over the last two decades [2], [9].…”

Section: Introductionmentioning

confidence: 99%

Mesoporous manganese oxides for NO2 assisted catalytic soot oxidation

Wasalathanthri

SantaMaria

Kriz

et al. 2017

Applied Catalysis B: Environmental

102

View full text Add to dashboard Cite

Air pollution issues due to soot/diesel particulate matter (DPM) emitted from incomplete burning of diesel fuel have become a global issue in this century. A series of manganese oxides, namely amorphous manganese oxide (Meso-Mn-A), Mn2O3 (Meso-Mn2O3), MnO2 (epsilon phase) (Meso-ϵ-MnO2) and octahedral molecular sieves MnO2 (Meso-OMS-2) was synthesized via a soft template method. The potential of mesoporous manganese oxides in acceleration of NO2 assisted catalytic oxidation of diesel soot (Printex-U) under lean conditions was investigated. The physiochemical properties of synthesized materials were systematically characterized by X-ray diffraction, N2-sorption, high-resolution transmission electron microscopy, and H2-temperature programmed reduction. A series of temperature programmed oxidation experiments was carried out to investigate the effect of feed gas composition on activity of the catalyst, and TGA-MS experiments were done to calculate the kinetic energy for each system. Mesoporous manganese oxides were found to be effective for complete oxidation of diesel soot under exhaust gas temperatures, and activities of all the manganese oxides were increased in the presence of NO2 in the feed gas. Meso-ϵ-MnO2 possesses the highest performance, exhibiting the lowest Ti and Tm (230 °C and 305 °C), the narrowest temperature range (75 °C), and the lowest Ea (298 kJ/mol).

show abstract

A novel dual layer SCR catalyst with a broad temperature window for the control of NO emission from diesel bus

Cited by 10 publications

References 15 publications

Effect of H₂O and SO₂ on the Selective Catalytic Reduction of NO with NH₃ Over Ce/TiO₂ Catalyst: Mechanism and Kinetic Study

Effect of H₂O and SO₂ on the Selective Catalytic Reduction of NO with NH₃ Over Ce/TiO₂ Catalyst: Mechanism and Kinetic Study

Global Kinetic Study of NO Reduction by NH₃ over V₂O₅–WO₃/TiO₂: Relationship between the SCR Performance and the Key Factors

Mesoporous manganese oxides for NO2 assisted catalytic soot oxidation

Contact Info

Product

Resources

About

A novel dual layer SCR catalyst with a broad temperature window for the control of NO emission from diesel bus

Cited by 10 publications

References 15 publications

Effect of H2O and SO2 on the Selective Catalytic Reduction of NO with NH3 Over Ce/TiO2 Catalyst: Mechanism and Kinetic Study

Effect of H2O and SO2 on the Selective Catalytic Reduction of NO with NH3 Over Ce/TiO2 Catalyst: Mechanism and Kinetic Study

Global Kinetic Study of NO Reduction by NH3 over V2O5–WO3/TiO2: Relationship between the SCR Performance and the Key Factors

Mesoporous manganese oxides for NO2 assisted catalytic soot oxidation

Contact Info

Product

Resources

About

Effect of H₂O and SO₂ on the Selective Catalytic Reduction of NO with NH₃ Over Ce/TiO₂ Catalyst: Mechanism and Kinetic Study

Effect of H₂O and SO₂ on the Selective Catalytic Reduction of NO with NH₃ Over Ce/TiO₂ Catalyst: Mechanism and Kinetic Study

Global Kinetic Study of NO Reduction by NH₃ over V₂O₅–WO₃/TiO₂: Relationship between the SCR Performance and the Key Factors