An investigation of alumina supported catalysts for the selective catalytic oxidation of ammonia in biomass gasification

L.I. Darvell, Katja Heiskanen, J.M. Jones (Corresponding Author), A.B. Ross, Pekka Simell, A. Williams

Research output: Contribution to journalArticleScientificpeer-review

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Abstract

Alumina-supported catalysts containing different transition metals (Ni, Cu, Cr, Mn, Fe and Co) were prepared and tested for their activity in the selective oxidation of ammonia reaction at high temperatures (between 700 and 900 °C) using a synthetic gasification gas mixture. The catalysts were also characterised for their acidic properties by infrared studies of pyridine and ammonia adsorption and reaction/desorption. The Ni/Al2O3 and Cr/Al2O3 catalyst displayed the highest selective catalytic oxidation (SCO) activity in that temperature range with excellent N2 selectivities. FT-IR studies of adsorbed pyridine and NH3 indicate that Lewis acid sites dominate and that NH3 adsorption on these sites is likely to be the first step in the SCO reaction. FT-IR studies on less active catalysts, particularly on Cu/Al2O3 allowed the detection of oxidation intermediates, amide (NH2), and possibly hydrazine and imido and nitroxyl species. The amide and hydrazine intermediate gives credence to a proposed SCO mechanism involving a hydrazine intermediate, while the proposed imide, N–H, and/or nitroxyl, HNO species could be intermediates in incomplete oxidation of NH3 to N2O.

Original languageEnglish
Pages (from-to)681-692
Number of pages12
JournalCatalysis Today
Volume81
Issue number4
DOIs
Publication statusPublished - 2003
MoE publication typeA1 Journal article-refereed
EventCatalyst Lifecycle Meeting - Bath, United Kingdom
Duration: 16 Sep 200217 Sep 2002

Fingerprint

hydrazine
Aluminum Oxide
Catalytic oxidation
Hydrazine
Gasification
Ammonia
Catalyst supports
Biomass
Alumina
Amides
Pyridine
Oxidation
Catalysts
Imides
Adsorption
Lewis Acids
Gas mixtures
Transition metals
Desorption
Infrared radiation

Keywords

  • gasification

Cite this

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title = "An investigation of alumina supported catalysts for the selective catalytic oxidation of ammonia in biomass gasification",
abstract = "Alumina-supported catalysts containing different transition metals (Ni, Cu, Cr, Mn, Fe and Co) were prepared and tested for their activity in the selective oxidation of ammonia reaction at high temperatures (between 700 and 900 °C) using a synthetic gasification gas mixture. The catalysts were also characterised for their acidic properties by infrared studies of pyridine and ammonia adsorption and reaction/desorption. The Ni/Al2O3 and Cr/Al2O3 catalyst displayed the highest selective catalytic oxidation (SCO) activity in that temperature range with excellent N2 selectivities. FT-IR studies of adsorbed pyridine and NH3 indicate that Lewis acid sites dominate and that NH3 adsorption on these sites is likely to be the first step in the SCO reaction. FT-IR studies on less active catalysts, particularly on Cu/Al2O3 allowed the detection of oxidation intermediates, amide (NH2), and possibly hydrazine and imido and nitroxyl species. The amide and hydrazine intermediate gives credence to a proposed SCO mechanism involving a hydrazine intermediate, while the proposed imide, N–H, and/or nitroxyl, HNO species could be intermediates in incomplete oxidation of NH3 to N2O.",
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author = "L.I. Darvell and Katja Heiskanen and J.M. Jones and A.B. Ross and Pekka Simell and A. Williams",
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An investigation of alumina supported catalysts for the selective catalytic oxidation of ammonia in biomass gasification. / Darvell, L.I.; Heiskanen, Katja; Jones, J.M. (Corresponding Author); Ross, A.B.; Simell, Pekka; Williams, A.

In: Catalysis Today, Vol. 81, No. 4, 2003, p. 681-692.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - An investigation of alumina supported catalysts for the selective catalytic oxidation of ammonia in biomass gasification

AU - Darvell, L.I.

AU - Heiskanen, Katja

AU - Jones, J.M.

AU - Ross, A.B.

AU - Simell, Pekka

AU - Williams, A.

PY - 2003

Y1 - 2003

N2 - Alumina-supported catalysts containing different transition metals (Ni, Cu, Cr, Mn, Fe and Co) were prepared and tested for their activity in the selective oxidation of ammonia reaction at high temperatures (between 700 and 900 °C) using a synthetic gasification gas mixture. The catalysts were also characterised for their acidic properties by infrared studies of pyridine and ammonia adsorption and reaction/desorption. The Ni/Al2O3 and Cr/Al2O3 catalyst displayed the highest selective catalytic oxidation (SCO) activity in that temperature range with excellent N2 selectivities. FT-IR studies of adsorbed pyridine and NH3 indicate that Lewis acid sites dominate and that NH3 adsorption on these sites is likely to be the first step in the SCO reaction. FT-IR studies on less active catalysts, particularly on Cu/Al2O3 allowed the detection of oxidation intermediates, amide (NH2), and possibly hydrazine and imido and nitroxyl species. The amide and hydrazine intermediate gives credence to a proposed SCO mechanism involving a hydrazine intermediate, while the proposed imide, N–H, and/or nitroxyl, HNO species could be intermediates in incomplete oxidation of NH3 to N2O.

AB - Alumina-supported catalysts containing different transition metals (Ni, Cu, Cr, Mn, Fe and Co) were prepared and tested for their activity in the selective oxidation of ammonia reaction at high temperatures (between 700 and 900 °C) using a synthetic gasification gas mixture. The catalysts were also characterised for their acidic properties by infrared studies of pyridine and ammonia adsorption and reaction/desorption. The Ni/Al2O3 and Cr/Al2O3 catalyst displayed the highest selective catalytic oxidation (SCO) activity in that temperature range with excellent N2 selectivities. FT-IR studies of adsorbed pyridine and NH3 indicate that Lewis acid sites dominate and that NH3 adsorption on these sites is likely to be the first step in the SCO reaction. FT-IR studies on less active catalysts, particularly on Cu/Al2O3 allowed the detection of oxidation intermediates, amide (NH2), and possibly hydrazine and imido and nitroxyl species. The amide and hydrazine intermediate gives credence to a proposed SCO mechanism involving a hydrazine intermediate, while the proposed imide, N–H, and/or nitroxyl, HNO species could be intermediates in incomplete oxidation of NH3 to N2O.

KW - gasification

U2 - 10.1016/S0920-5861(03)00166-4

DO - 10.1016/S0920-5861(03)00166-4

M3 - Article

VL - 81

SP - 681

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JO - Catalysis Today

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SN - 0920-5861

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