Coated bifunctional catalysts for NOx SCR with C3H6

Castagnola, Mario; Neylon, Michael K.; Marshall, Christopher L.

doi:10.1016/j.cattod.2004.05.001

Cited by 15 publications

(7 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Besides NH 3 -SCR, the presence of NO 2 in a feed has been frequently reported to be beneficial for the conversion of NO into N 2 for the SCR of NO with hydrocarbons [11][12][13][14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

NO oxidation over supported cobalt oxide catalysts

Kim

Yie

et al. 2010

Korean J. Chem. Eng.

View full text Add to dashboard Cite

NO oxidation was conducted over cobalt oxides supported on various supports such as SiO 2 , ZrO 2 , TiO 2 , and CeO 2 . The N 2 physisorption, an inductively coupled plasma-atomic emission spectroscopy (ICP-AES), X-ray diffraction (XRD), NO chemisorptions, the temperature-programmed desorption (TPD) with a mass spectroscopy after NO or CO chemisorptions were conducted to characterize catalysts. Among tested catalysts, Co 3 O 4 supported on ceria with a high surface area showed the highest catalytic activity. This catalyst showed superior catalytic activity to unsupported Co 3 O 4 with a high surface area and 1 wt% Pt/γ-Al 2 O 3 . For ceria-supported Co 3 O 4 , the catalytic activity, the NO uptake at 298 K and the dispersion of Co 3 O 4 increased with increasing the surface area of CeO 2 . The active participation of the lattice oxygen in NO oxidation could not be observed. On the other hand, the lattice oxygen participated in the CO oxidation over the same catalyst. The deactivation was observed over Co 3 O 4 /CeO 2 and 1 wt% Pt/γ-Al 2 O 3 in the presence of SO 2 in a feed. 1 wt% Pt/γ-Al 2 O 3 was deactivated by SO 2 more rapidly compared with Co 3 O 4 /CeO 2 .

show abstract

Section: Introductionmentioning

confidence: 99%

NO oxidation over supported cobalt oxide catalysts

Kim

Yie

et al. 2010

Korean J. Chem. Eng.

View full text Add to dashboard Cite

show abstract

“…The enhancement in the de-NO x rate can be noticeable especially at low temperatures such as 200-300 o C when the equimolar amounts of NO and NO 2 are present in a feed (fast SCR process). This beneficial effect on SCR in the presence of NO 2 has also been reported for the SCR of NO with hydrocarbons [11][12][13][14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 53%

The effect of cobalt precursors on NO oxidation over supported cobalt oxide catalysts

Kim

Yie

et al. 2010

Korean J. Chem. Eng.

View full text Add to dashboard Cite

The effect of cobalt precursors such as cobalt acetate and cobalt nitrate on NO oxidation was examined over cobalt oxides supported on various supports such as SiO 2 , ZrO 2 , and CeO 2 . The N 2 physisorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), temperature-programmed reduction with H 2 (H 2 -TPR), NO chemisorptions, and temperature-programmed oxidation (TPO) with mass spectroscopy were conducted to characterize catalysts. The NO uptake as well as the catalytic activity for NO oxidation was dependent on the kinds of cobalt precursors and supports for supported cobalt oxides catalysts. Among tested catalysts, Co 3 O 4 /CeO 2 prepared from cobalt acetate showed the highest catalytic activity. The catalytic activity generally increased with the amount of chemisorbed NO. Reversible deactivation was observed over Co 3 O 4 /CeO 2 in the presence of H 2 O. On the other hand, irreversible deactivation occurred over the same catalyst even in the presence of 5 ppm SO 2 in a feed. The strongly adsorbed SO 2 can prohibit NO from adsorbing on the active sites and also can prevent formed NO 2 from desorbing off the catalyst surface. The formation of SO 3 cannot be observed from the chemisorbed SO 2 on Co 3 O 4 /CeO 2 during TPO.

show abstract

“…Dessa forma, os óxidos de nitrogênio e também os óxidos de enxofre são removidos usando-se um catalisador conveniente. As limitações decorrentes do uso de amônia como agente redutor possibilitaram o avanço das pesquisas na busca por novos catalisadores e incentivou a substituição da amônia por hidrocarbonetos na SCR 6,9 . Nesse sentido, propano e metano são os hidrocarbonetos mais empregados na redução seletiva do óxido nítrico.…”

Section: Introductionunclassified

“…A utilização do propano como agente redutor deve-se ao fato deste hidrocarboneto ser o componente mais representativo dos gases de exaustão em veículos automotivos. Por outro lado, o uso do metano é incentivado devido à sua abundân-cia, bem como sua aplicação como combustível em fontes estacionárias 9,10 . Nos últimos anos, vários catalisadores foram avaliados na redução catalítica seletiva usando hidrocarbonetos [10][11][12] .…”

Section: Introductionunclassified

“…Entre esses materiais, os catalisadores Cu-ZSM-5 e Co-ZSM-5 foram os primeiros empregados nessa reação. Entretanto, observou-se que esses sólidos apresentavam forte inibição da atividade catalítica em presença de vapor de água e/ou óxido de enxofre 9 . Recentemente, mostrou-se que a presença de ferro em zeólitas aumenta a estabilidade desses catalisadores em condições hidrotérmicas, mas forma monóxido de carbono como subproduto da reação 13 .…”

Section: Introductionunclassified

See 1 more Smart Citation