Metal doped sulfated ZrO2 as catalyst for the selective catalytic reduction (SCR) of NO with propane

Pasel, Joachim; Speer, Volker; Albrecht, Christiane; Richter, Frauke; Papp, H.

doi:10.1016/s0926-3373(99)00126-5

Cited by 35 publications

(22 citation statements)

References 26 publications

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“…Zirconia was prepared by hydrolysis of ZrCl 4 (Merck, for synthesis) with a concentrated (25%) solution of ammonia. During the dissolution of ZrCl 4 in water (0.3 mol of ZrCl 4 /L) and addition of ammonia solution, the temperature was kept below 343 K. The precipitate was washed thoroughly with deionized water to remove the chloride ions, dried at 393 K for 12 h, and calcined for 4 h at 773 K. The BET surface area was 69 m 2 /g, and according to XRD, the substance was predominantly monoclinic (94%).…”

Section: Methodsmentioning

confidence: 99%

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FTIR Spectroscopic Characterization of NO_xSpecies Adsorbed on ZrO₂and ZrO₂−SO₄^2-

Kantcheva

Ciftlikli

2002

J. Phys. Chem. B

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The nature of the NO x species produced during the adsorption of NO at room temperature and during its coadsorption with oxygen on pure and sulfated zirconia has been investigated by means of in situ FTIR spectroscopy. The adsorption of NO on both samples occurs through disproportionation leading to the formation of nitrous acid; water molecules; nitro species; and anionic nitrosyls, NO -. A mechanism for the formation of these adsorption forms is proposed. The NO -species are stable on the surface of zirconia, whereas on the sulfated sample, they are readily oxidized by the SO 4 2-groups. The process of NO disproportionation is favored by wet surfaces and occurs with participation of the tribridged (ZrO 2 ) and terminal (ZrO 2 -SO 4 2-) hydroxyl groups. Coadsorption of NO and O 2 on pure zirconia leads to the formation of various kinds of nitrate species. The presence of sulfate ions reduces the amount of surface nitrates and decreases their thermal stability. An analysis of the combination bands of the nitrate species shows that this spectral region can be used for structural identification of bidentate and bridged nitrates.

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Section: Methodsmentioning

confidence: 99%

“…Sulfated zirconia was prepared by impregnation of the calcined material with a solution of (NH 4 ) 2 SO 4 . The nominal content of the sulfate ions was 3.8 wt %.…”

Section: Methodsmentioning

confidence: 99%

FTIR Spectroscopic Characterization of NO_xSpecies Adsorbed on ZrO₂and ZrO₂−SO₄^2-

Kantcheva

Ciftlikli

2002

J. Phys. Chem. B

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“…Recent reports have shown that oxide catalysts based on copper-supported on zirconia or sulfated zirconia are promising in the selective catalytic reduction of NO x with hydrocarbons (CH-SCR) and ammonia in an excess of oxygen [1][2][3][4][5][6][7][8][9][10]. In addition, zirconiasupported copper oxide catalysts possess very high activity for NO reduction with CO at low tempera-tures [11][12][13][14][15][16][17] and comparable catalytic behavior with Cu-ZSM5 in the decomposition of N 2 O [18][19][20].…”

Section: Introductionmentioning

confidence: 99%

FT-IR spectroscopic investigation of the reactivity of NOx species adsorbed on Cu2+/ZrO2 and CuSO4/ZrO2 catalysts toward decane

Kantcheva

2003

Applied Catalysis B: Environmental

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The nature of the NO x species produced on NO adsorption and its co-adsorption with O 2 at room temperature on zirconia-supported copper(II) catalysts has been studied by means of in situ FT-IR spectroscopy. The samples were prepared by impregnation of zirconia with aqueous solutions of copper(II) nitrate and sulfate. The structural identification of the surface NO x complexes exhibiting absorptions in the fundamental nitro-nitrato region was performed by analyzing the combination bands of the nitrate species. In order to understand which factors control the selectivity of the catalysts in the catalytic reduction of NO by longer chain hydrocarbons, the stability of surface nitro-nitrato species and their reactivity toward adsorbed decane at various temperatures was investigated. The nitrates on the CuSO 4 /ZrO 2 catalyst are characterized by significantly lower thermal stability than the nitro-nitrato species on the Cu 2+ /ZrO 2 sample. The difference in the thermal stability of the NO x − species (x is 2 and 3) parallels their reactivity toward the adsorbed decane. The sulfate-free catalyst contains bidentate nitro species that are inert toward the hydrocarbon. The bidentate nitro species start to decompose to NO at temperatures higher than 523 K. In contrast, the nitrate species formed on the CuSO 4 /ZrO 2 catalyst are able to oxidize the adsorbed decane completely at 523 K producing acetates, formates, adsorbed CO and isocyanate species. It is proposed that the presence of stable nitro species on the sulfate-free copper(II)-zirconia catalyst is associated with its non-selective behavior above 573 K in the reduction of NO with decane in an excess of oxygen reported in the literature.

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“…Sulfation of Pt or Pt + Cu-loaded samples was carried out following earlier described procedures [23][24][25][26][27] by impregnation with (NH 4 ) 2 SO 4 solutions followed by drying and calcinations at 500 8C. In all cases, the sulfur content was kept at about 1 wt.% S as determined by the chemical analysis.…”

Section: Methodsmentioning

confidence: 99%

“…7) which can be assigned to decomposition of different surface complexes including nitrosyl, nitrite and nitrate species [13,20,22,27,32]. In these adsorption conditions, N 2 O 3 or adsorbed HNO 2 fixed at Zr 4+ cations could exist as well [22].…”

Section: No X Tpdmentioning

confidence: 99%

NOx SCR by decane and propylene on Pt+Cu/Zr-pillared clays in realistic feeds: Performance and mechanistic features versus structural specificity of nanosized zirconia pillars

et al. 2006

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Metal doped sulfated ZrO2 as catalyst for the selective catalytic reduction (SCR) of NO with propane

Cited by 35 publications

References 26 publications

FTIR Spectroscopic Characterization of NO_xSpecies Adsorbed on ZrO₂and ZrO₂−SO₄^2-

FTIR Spectroscopic Characterization of NO_xSpecies Adsorbed on ZrO₂and ZrO₂−SO₄^2-

FT-IR spectroscopic investigation of the reactivity of NOx species adsorbed on Cu2+/ZrO2 and CuSO4/ZrO2 catalysts toward decane

NOx SCR by decane and propylene on Pt+Cu/Zr-pillared clays in realistic feeds: Performance and mechanistic features versus structural specificity of nanosized zirconia pillars

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Metal doped sulfated ZrO2 as catalyst for the selective catalytic reduction (SCR) of NO with propane

Cited by 35 publications

References 26 publications

FTIR Spectroscopic Characterization of NOxSpecies Adsorbed on ZrO2and ZrO2−SO42-

FTIR Spectroscopic Characterization of NOxSpecies Adsorbed on ZrO2and ZrO2−SO42-

FT-IR spectroscopic investigation of the reactivity of NOx species adsorbed on Cu2+/ZrO2 and CuSO4/ZrO2 catalysts toward decane

NOx SCR by decane and propylene on Pt+Cu/Zr-pillared clays in realistic feeds: Performance and mechanistic features versus structural specificity of nanosized zirconia pillars

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FTIR Spectroscopic Characterization of NO_xSpecies Adsorbed on ZrO₂and ZrO₂−SO₄^2-

FTIR Spectroscopic Characterization of NO_xSpecies Adsorbed on ZrO₂and ZrO₂−SO₄^2-