Sol-gel processed silica-alumina materials for diesel engine emission reduction catalysts

C. K. Narula; M. Rokosz; L. F. Allard; R. J. Kudla; M. S. Chattha

doi:10.1021/la991090s

Sol-gel processed silica-alumina materials for diesel engine emission reduction catalysts

C. K. Narula, M. Rokosz, L. F. Allard, R. J. Kudla, M. S. Chattha

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

12 Scopus citations

Abstract

The incorporation of >30% silica in alumina prior to platinum impregnation improves the NOx conversion efficiency in the 200-300 °C range from 45 to 57% and reduces light-off temperature. Further increase in the amount of silica to 50% is detrimental to NOx conversion efficiency. The ¹H and ²⁹Si NMR of the materials suggest that this trend is probably related to the surface acidity. The analyses of these materials by X-ray powder diffraction and electron microscopy do not reveal significant differences. Additional NOx conversion in the 350-450 °C range with a maximum of 30% at 400 °C can be achieved if a rhodium-impregnated 30% silica-alumina. Rh-30% SiO₂-Al₂O₃, is placed upstream of Pt-30% SiO₂-Al₂O₃. It is important to note that mixing Pt-30% SiO₂-Al₂O₃ with Rh-30% SiO₂-Al₂O₃ does nor enhance conversion efficiency or effective temperature range.

Original language	English
Pages (from-to)	3818-3822
Number of pages	5
Journal	Langmuir
Volume	16
Issue number	8
DOIs	https://doi.org/10.1021/la991090s
State	Published - Apr 18 2000
Externally published	Yes

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10.1021/la991090s

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@article{54da5b36f3004782a8aca50926b77671,

title = "Sol-gel processed silica-alumina materials for diesel engine emission reduction catalysts",

abstract = "The incorporation of >30\% silica in alumina prior to platinum impregnation improves the NOx conversion efficiency in the 200-300 °C range from 45 to 57\% and reduces light-off temperature. Further increase in the amount of silica to 50\% is detrimental to NOx conversion efficiency. The 1H and 29Si NMR of the materials suggest that this trend is probably related to the surface acidity. The analyses of these materials by X-ray powder diffraction and electron microscopy do not reveal significant differences. Additional NOx conversion in the 350-450 °C range with a maximum of 30\% at 400 °C can be achieved if a rhodium-impregnated 30\% silica-alumina. Rh-30\% SiO2-Al2O3, is placed upstream of Pt-30\% SiO2-Al2O3. It is important to note that mixing Pt-30\% SiO2-Al2O3 with Rh-30\% SiO2-Al2O3 does nor enhance conversion efficiency or effective temperature range.",

author = "Narula, \{C. K.\} and M. Rokosz and Allard, \{L. F.\} and Kudla, \{R. J.\} and Chattha, \{M. S.\}",

year = "2000",

month = apr,

day = "18",

doi = "10.1021/la991090s",

language = "English",

volume = "16",

pages = "3818--3822",

journal = "Langmuir",

issn = "0743-7463",

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TY - JOUR

T1 - Sol-gel processed silica-alumina materials for diesel engine emission reduction catalysts

AU - Narula, C. K.

AU - Rokosz, M.

AU - Allard, L. F.

AU - Kudla, R. J.

AU - Chattha, M. S.

PY - 2000/4/18

Y1 - 2000/4/18

N2 - The incorporation of >30% silica in alumina prior to platinum impregnation improves the NOx conversion efficiency in the 200-300 °C range from 45 to 57% and reduces light-off temperature. Further increase in the amount of silica to 50% is detrimental to NOx conversion efficiency. The 1H and 29Si NMR of the materials suggest that this trend is probably related to the surface acidity. The analyses of these materials by X-ray powder diffraction and electron microscopy do not reveal significant differences. Additional NOx conversion in the 350-450 °C range with a maximum of 30% at 400 °C can be achieved if a rhodium-impregnated 30% silica-alumina. Rh-30% SiO2-Al2O3, is placed upstream of Pt-30% SiO2-Al2O3. It is important to note that mixing Pt-30% SiO2-Al2O3 with Rh-30% SiO2-Al2O3 does nor enhance conversion efficiency or effective temperature range.

AB - The incorporation of >30% silica in alumina prior to platinum impregnation improves the NOx conversion efficiency in the 200-300 °C range from 45 to 57% and reduces light-off temperature. Further increase in the amount of silica to 50% is detrimental to NOx conversion efficiency. The 1H and 29Si NMR of the materials suggest that this trend is probably related to the surface acidity. The analyses of these materials by X-ray powder diffraction and electron microscopy do not reveal significant differences. Additional NOx conversion in the 350-450 °C range with a maximum of 30% at 400 °C can be achieved if a rhodium-impregnated 30% silica-alumina. Rh-30% SiO2-Al2O3, is placed upstream of Pt-30% SiO2-Al2O3. It is important to note that mixing Pt-30% SiO2-Al2O3 with Rh-30% SiO2-Al2O3 does nor enhance conversion efficiency or effective temperature range.

UR - https://www.scopus.com/pages/publications/0033741829

U2 - 10.1021/la991090s

DO - 10.1021/la991090s

M3 - Article

AN - SCOPUS:0033741829

SN - 0743-7463

VL - 16

SP - 3818

EP - 3822

JO - Langmuir

JF - Langmuir

IS - 8

ER -

Sol-gel processed silica-alumina materials for diesel engine emission reduction catalysts

Abstract

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