Support and particle size effects on direct NO decomposition over platinum

Xianqin Wang; Susan M. Sigmon; James J. Spivey; H. Henry Lamb

doi:10.1016/j.cattod.2004.05.003

Support and particle size effects on direct NO decomposition over platinum

Xianqin Wang, Susan M. Sigmon, James J. Spivey, H. Henry Lamb

Research output: Contribution to journal › Article › peer-review

36 Scopus citations

Abstract

Supported Pt catalysts were prepared by ion exchange of Pt(II) tetraamine hydroxide [Pt(NH₃)₄(OH)₂] onto SiO ₂, Al₂O₃, and TiO₂ and by adsorption of Pt bis-acetylacetonate [Pt(acac)₂] onto MgO. All the catalysts except Pt/TiO₂ were characterized by in situ X-ray absorption fine structure (XAFS) spectroscopy after reduction at 300°C in flowing H₂, and the Pt/SiO₂ and Pt/MgO catalysts were examined after subsequent exposure to 1% NO/He at 25-300°C. NO decomposition pathways were investigated by temperature-programmed reaction spectroscopy (TPRS) using a 1% NO/He feed, and steady-state conversions for direct NO decomposition were measured at 600°C. NO decomposition at low temperatures (200-400°C) produces N₂O and N₂, and in situ XAFS spectroscopy indicates that the supported Pt particles are partially oxidized under these conditions. Over each catalyst, O₂ production begins at ∼350°C; N₂O production declines above 400°C; and N₂ and O₂ are the only detectable NO decomposition products at 600°C. Nanometer-sized Pt clusters on SiO₂ sinter during heating in 1% NO/He at 300°C, whereas larger Pt particles supported on SiO₂ and MgO are resistant to sintering under these conditions. The turnover frequency for direct NO decomposition over Pt/SiO₂ catalysts is insensitive to Pt particle size. Pt/SiO₂, Pt/Al ₂O₃, and Pt/TiO₂ catalysts have equivalent NO decomposition activities suggesting the absence of support effects for these metal oxides. In contrast, the NO decomposition activity of Pt supported on strongly basic MgO is significantly lower.

Original language	English (US)
Pages (from-to)	11-20
Number of pages	10
Journal	Catalysis Today
Volume	96
Issue number	1-2
DOIs	https://doi.org/10.1016/j.cattod.2004.05.003
State	Published - 2004
Externally published	Yes

All Science Journal Classification (ASJC) codes

Catalysis
General Chemistry

Keywords

EXAFS spectroscopy
NO decomposition
Particle size effects
Support effects
Temperature-programmed reaction spectroscopy
XANES spectroscopy

Access to Document

10.1016/j.cattod.2004.05.003

Cite this

@article{22dd2cad1b3640f9a6c859740249ba39,

title = "Support and particle size effects on direct NO decomposition over platinum",

abstract = "Supported Pt catalysts were prepared by ion exchange of Pt(II) tetraamine hydroxide [Pt(NH3)4(OH)2] onto SiO 2, Al2O3, and TiO2 and by adsorption of Pt bis-acetylacetonate [Pt(acac)2] onto MgO. All the catalysts except Pt/TiO2 were characterized by in situ X-ray absorption fine structure (XAFS) spectroscopy after reduction at 300°C in flowing H2, and the Pt/SiO2 and Pt/MgO catalysts were examined after subsequent exposure to 1% NO/He at 25-300°C. NO decomposition pathways were investigated by temperature-programmed reaction spectroscopy (TPRS) using a 1% NO/He feed, and steady-state conversions for direct NO decomposition were measured at 600°C. NO decomposition at low temperatures (200-400°C) produces N2O and N2, and in situ XAFS spectroscopy indicates that the supported Pt particles are partially oxidized under these conditions. Over each catalyst, O2 production begins at ∼350°C; N2O production declines above 400°C; and N2 and O2 are the only detectable NO decomposition products at 600°C. Nanometer-sized Pt clusters on SiO2 sinter during heating in 1% NO/He at 300°C, whereas larger Pt particles supported on SiO2 and MgO are resistant to sintering under these conditions. The turnover frequency for direct NO decomposition over Pt/SiO2 catalysts is insensitive to Pt particle size. Pt/SiO2, Pt/Al 2O3, and Pt/TiO2 catalysts have equivalent NO decomposition activities suggesting the absence of support effects for these metal oxides. In contrast, the NO decomposition activity of Pt supported on strongly basic MgO is significantly lower.",

keywords = "EXAFS spectroscopy, NO decomposition, Particle size effects, Support effects, Temperature-programmed reaction spectroscopy, XANES spectroscopy",

author = "Xianqin Wang and Sigmon, {Susan M.} and Spivey, {James J.} and Lamb, {H. Henry}",

note = "Funding Information: This research was sponsored by Caterpillar, Inc. and the US Department of Energy. The XAS experiments were performed using beam line X-11A of the National Synchrotron Light Source at Brookhaven National Laboratory. The authors wish to thank Bryan Silletti of Caterpillar for his contributions to this work. ",

year = "2004",

doi = "10.1016/j.cattod.2004.05.003",

language = "English (US)",

volume = "96",

pages = "11--20",

journal = "Catalysis Today",

issn = "0920-5861",

publisher = "Elsevier B.V.",

number = "1-2",

}

TY - JOUR

T1 - Support and particle size effects on direct NO decomposition over platinum

AU - Wang, Xianqin

AU - Sigmon, Susan M.

AU - Spivey, James J.

AU - Lamb, H. Henry

N1 - Funding Information: This research was sponsored by Caterpillar, Inc. and the US Department of Energy. The XAS experiments were performed using beam line X-11A of the National Synchrotron Light Source at Brookhaven National Laboratory. The authors wish to thank Bryan Silletti of Caterpillar for his contributions to this work.

PY - 2004

Y1 - 2004

N2 - Supported Pt catalysts were prepared by ion exchange of Pt(II) tetraamine hydroxide [Pt(NH3)4(OH)2] onto SiO 2, Al2O3, and TiO2 and by adsorption of Pt bis-acetylacetonate [Pt(acac)2] onto MgO. All the catalysts except Pt/TiO2 were characterized by in situ X-ray absorption fine structure (XAFS) spectroscopy after reduction at 300°C in flowing H2, and the Pt/SiO2 and Pt/MgO catalysts were examined after subsequent exposure to 1% NO/He at 25-300°C. NO decomposition pathways were investigated by temperature-programmed reaction spectroscopy (TPRS) using a 1% NO/He feed, and steady-state conversions for direct NO decomposition were measured at 600°C. NO decomposition at low temperatures (200-400°C) produces N2O and N2, and in situ XAFS spectroscopy indicates that the supported Pt particles are partially oxidized under these conditions. Over each catalyst, O2 production begins at ∼350°C; N2O production declines above 400°C; and N2 and O2 are the only detectable NO decomposition products at 600°C. Nanometer-sized Pt clusters on SiO2 sinter during heating in 1% NO/He at 300°C, whereas larger Pt particles supported on SiO2 and MgO are resistant to sintering under these conditions. The turnover frequency for direct NO decomposition over Pt/SiO2 catalysts is insensitive to Pt particle size. Pt/SiO2, Pt/Al 2O3, and Pt/TiO2 catalysts have equivalent NO decomposition activities suggesting the absence of support effects for these metal oxides. In contrast, the NO decomposition activity of Pt supported on strongly basic MgO is significantly lower.

AB - Supported Pt catalysts were prepared by ion exchange of Pt(II) tetraamine hydroxide [Pt(NH3)4(OH)2] onto SiO 2, Al2O3, and TiO2 and by adsorption of Pt bis-acetylacetonate [Pt(acac)2] onto MgO. All the catalysts except Pt/TiO2 were characterized by in situ X-ray absorption fine structure (XAFS) spectroscopy after reduction at 300°C in flowing H2, and the Pt/SiO2 and Pt/MgO catalysts were examined after subsequent exposure to 1% NO/He at 25-300°C. NO decomposition pathways were investigated by temperature-programmed reaction spectroscopy (TPRS) using a 1% NO/He feed, and steady-state conversions for direct NO decomposition were measured at 600°C. NO decomposition at low temperatures (200-400°C) produces N2O and N2, and in situ XAFS spectroscopy indicates that the supported Pt particles are partially oxidized under these conditions. Over each catalyst, O2 production begins at ∼350°C; N2O production declines above 400°C; and N2 and O2 are the only detectable NO decomposition products at 600°C. Nanometer-sized Pt clusters on SiO2 sinter during heating in 1% NO/He at 300°C, whereas larger Pt particles supported on SiO2 and MgO are resistant to sintering under these conditions. The turnover frequency for direct NO decomposition over Pt/SiO2 catalysts is insensitive to Pt particle size. Pt/SiO2, Pt/Al 2O3, and Pt/TiO2 catalysts have equivalent NO decomposition activities suggesting the absence of support effects for these metal oxides. In contrast, the NO decomposition activity of Pt supported on strongly basic MgO is significantly lower.

KW - EXAFS spectroscopy

KW - NO decomposition

KW - Particle size effects

KW - Support effects

KW - Temperature-programmed reaction spectroscopy

KW - XANES spectroscopy

UR - http://www.scopus.com/inward/record.url?scp=4644332350&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=4644332350&partnerID=8YFLogxK

U2 - 10.1016/j.cattod.2004.05.003

DO - 10.1016/j.cattod.2004.05.003

M3 - Article

AN - SCOPUS:4644332350

SN - 0920-5861

VL - 96

SP - 11

EP - 20

JO - Catalysis Today

JF - Catalysis Today

IS - 1-2

ER -

Support and particle size effects on direct NO decomposition over platinum

Abstract

All Science Journal Classification (ASJC) codes

Keywords

Access to Document

Other files and links

Fingerprint

Cite this