Copper(II) ion-exchanged ZSM-5 zeolites as highly active catalysts for direct and continuous decomposition of nitrogen monoxide

Iwamoto, Masakazu; Furukawa, Hiroshi; Mine, Yoshihiro; Uemura, Fumihide; Mikuriya, Shin-ichi; Kagawa, Shuichi

doi:10.1039/c39860001272

Cited by 517 publications

(327 citation statements)

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“…A whole series of catalysts was explored over the last 50 years, but no appreciable reaction rates were obtained till the epochmaking finding of Iwamoto et al in 1986 [5]. They reported the uniquely high and stable activity of overexchanged Cu-ZSM-5 for the direct NO decomposition [5]. However, tests under conditions representative of automotive exhaust gases pointed toward two important limitations of Cu-ZSM-5 for a practical application: (1) a too low activity by 1-2 orders of magnitude and (2) the suppression of the activity by water vapor and SO 2 [1].…”

Section: Introductionmentioning

confidence: 99%

An operando optical fiber UV–vis spectroscopic study of the catalytic decomposition of NO and N2O over Cu-ZSM-5

Groothaert

Lievens

Leeman

et al. 2003

Journal of Catalysis

137

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The role of the bis(µ-oxo)dicopper core, i.e., [Cu 2 (µ-O) 2 ] 2+ , in the decomposition of NO and N 2 O by the Cu-ZSM-5 zeolite has been studied with combined operando UV-vis monitoring of the catalyst and on-line GC analysis. An optical fiber was mounted on the outer surface of the quartz wall of the plug-flow reactor and collected the UV-vis diffuse reflectance spectra under true catalytic conditions.

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Section: Introductionmentioning

confidence: 99%

An operando optical fiber UV–vis spectroscopic study of the catalytic decomposition of NO and N2O over Cu-ZSM-5

Groothaert

Lievens

Leeman

et al. 2003

Journal of Catalysis

137

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“…Solid-state 31 P NMR spectra were recorded at 161.9 MHz with a spinning rate of 10 kHz, a π/2 pulse of 5 μs with 20 s repetition time. 29 Si, 27 Al and 31 P chemical shifts were referred to tetramethylsilane, Al 3+ (H 2 O) 6 , and 85% H 3 PO 4 , respectively.…”

Section: The Chemical Analyses Were Carried Out In a Varian 715-es Icmentioning

confidence: 99%

“…The discovery of copper-exchanged zeolites as active and stable catalysts for the SCR of NOx by Iwamoto et al introduced an attractive alternative to vanadia-based materials [6]. Several metal-exchanged molecular sieves, primary medium and large pore zeolites, have been reported in the last two decades for the SCR of NOx [7].…”

Section: -Introductionmentioning

confidence: 99%

Rational direct synthesis methodology of very active and hydrothermally stable Cu-SAPO-34 molecular sieves for the SCR of NOx

Martínez-Franco

Moliner

Franch

et al. 2012

Applied Catalysis B: Environmental

158

103

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A one-pot direct synthesis of Cu-SAPO-34 has been achieved that allows more than 90% yield in the material synthesis. By this method it is easy to control the Cu-loading in the Cu-SAPO-34. It is presented that a maximum in hydrothermal stability with very high activity for NOx SCR with NH 3 is obtained for an optimum Cu loading. KeywordsOne-pot synthesis, silicoaluminophosphate, SAPO-34, selective catalytic reduction (SCR), nitrogen oxides (NOx) Highlights-Rational direct synthesis of Cu-SAPO-34 by using the co-directing templates.-Easy control of Cu-loading in Cu-SAPO-34 materials, and very high solid yields.-High activity and stability for SCR of NOx. In fact, the SCR of NOx experiment described by Xiao was performed on the sample with Si/Al ratio of 4.1 under mild conditions (low space velocity), and the stability of the synthesized samples under hydrothermal treatments was not studied. In addition to SSZ-13, the chabazite molecular sieve can be synthesized as silicoaluminophosphate form, . Cu-exchanged SAPO-34 has also been shown as a very stable and active material for SCR of NOx [14]. In the last years, some groups have attempted the direct preparation of Cu-SAPO-34 in order to achieve an inexpensive and more efficient synthetic route for this metal-substituted material [15].In those cases morfoline and copper oxide were used as organic structure directing with the tetraethylenepentamine (TEPA, 99%wt, Aldrich). This mixture was stirred for 2 hours until complete dissolution. Secondly, distilled water and phosphoric acid (85% wt, Aldrich) were added and stirred during 5 minutes. Third, alumina (75%wt, Condea) 7 and silica (Ludox AS40 40%wt, Aldrich) sources were introduced in the gel mixture.Finally, diethylamine (DEA, 99%wt, Aldrich) and SAPO-34 seeds (5%wt of expected final yield), if required, were added in the gel, and the mixture was stirred during 30 minutes. The resulting gel was transferred to an autoclave with a Teflon liner, and heated at 150ºC under static conditions during the required time (see experimental conditions for each sample in Table 1, Table 3, or Table 4). Crystalline products were filtered and washed with abundant water, and dried at 100ºC overnight. The samples were calcined at 550ºC in air to properly remove the occluded organic species. washed with distilled water, and dried at 100ºC overnight. The sample was calcined at 550ºC in air to remove the occluded organic species.In order to perform the Cu ion exchange on this SAPO-34 material, the calcined sample was first washed with NaNO 3 (0.04M), and afterwards, the sample was exchanged at room temperature with a Cu(CH 3 CO 2 ) 2 solution (solid/liquid ratio of 10g/L). Finally, the sample was filtered and washed with distilled water, and calcined at 550ºC for 4 h. 2.2.-CharacterizationX-ray diffraction (XRD) measurements were performed on a multisample Philips X'Pert diffractometer equipped with a graphite monochromator, operating at 40 kV and 45 mA, and usig Cu K α radiation (λ = 0,1542 nm).The chemical analyses were car...

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“…A variety of materials have been studied for their ability to catalyse these processes, and these include various kinds of zeolites, metal oxides and supported noble metal catalysts. Cu-ZSM-5, a copper ion-exchanged zeolite, has been reported to be a much more efficient catalyst for the elimination of NO than the earlier known catalysts for the catalytic reduction of this gas [24]. However, its activity decreases sharply with a decrease in the NO concentration, and it suffers from severe deactivation in the presence of oxygen or sulphur oxides [24].…”

Section: Catalytic Conversion Of Pollutants In Automobile Emissions Umentioning

confidence: 99%

“…Cu-ZSM-5, a copper ion-exchanged zeolite, has been reported to be a much more efficient catalyst for the elimination of NO than the earlier known catalysts for the catalytic reduction of this gas [24]. However, its activity decreases sharply with a decrease in the NO concentration, and it suffers from severe deactivation in the presence of oxygen or sulphur oxides [24]. In another study, it was found that Ga-ZSM-5 and In-ZSM-5 catalysts were highly active and selective for NO reduction by CH 4 .…”

Section: Catalytic Conversion Of Pollutants In Automobile Emissions Umentioning

confidence: 99%

Gold, an alternative to platinum group metals in automobile catalytic converters

et al. 2011

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Catalytic convertors based on the use of platinum, palladium and rhodium play a major role in the cleaning of automobile emissions. Gold, when dispersed as nano-sized particles, has demonstrated significant activity in the conversion of toxic components, including carbon monoxide, unburnt hydrocarbons and nitrogen oxides, in engine emissions and some advantages over the platinum group metals. Some research outcomes on the application of nano-sized gold for the conversion of these components are reviewed. Several key issues in relation to its performance and applicability in catalytic convertors such as low-temperature activity and thermal stability and the possibilities of substituting platinum group metals for automobile emission control with gold are discussed.

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Copper(II) ion-exchanged ZSM-5 zeolites as highly active catalysts for direct and continuous decomposition of nitrogen monoxide

Cited by 517 publications

References 1 publication

An operando optical fiber UV–vis spectroscopic study of the catalytic decomposition of NO and N2O over Cu-ZSM-5

An operando optical fiber UV–vis spectroscopic study of the catalytic decomposition of NO and N2O over Cu-ZSM-5

Rational direct synthesis methodology of very active and hydrothermally stable Cu-SAPO-34 molecular sieves for the SCR of NOx

Gold, an alternative to platinum group metals in automobile catalytic converters

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