Ultraviolet Raman spectroscopy characterization of coke formation in zeolites

Can Li; Peter C. Stair

doi:10.1016/S0920-5861(96)00120-4

Ultraviolet Raman spectroscopy characterization of coke formation in zeolites

Can Li^*, Peter C. Stair

^*Corresponding author for this work

Chemistry

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

156 Scopus citations

Abstract

Ultraviolet (UV) Raman spectroscopy has been used to characterize coke formation in ZSM-5 and USY zeolites under propene at temperatures from 300K to 773K. The strong fluorescence background always present with normal Raman spectra is completely avoided in UV Raman spectra. Three groups of UV Raman bands near ~ 1390, ~ 1600 and ~ 3000 cm^-1 regions were detected for the two zeolites, and these bands varied significantly at different stages of coke formation. At room temperature, adsorbed propene was formed in the two zeolites and showed similar spectra. At elevated temperatures, the coke formation behavior in the two zeolites is quite different. For example, at 773K the coke species in ZSM-5 are mainly polyolefinic and aromatic species, but poly aromatic and pregraphite species are predominant in USY. The major portion of coke species formed in ZSM-5 can be removed even by He purging at 773K while the coke species in USY are very stable and can only be removed in O₂ flow at temperatures above 773K. The difference in coke formation in ZSM-5 and USY is likely due to the different pore structure and acidity of the two zeolites.

Original language	English (US)
Pages (from-to)	353-360
Number of pages	8
Journal	Catalysis Today
Volume	33
Issue number	1-3
DOIs	https://doi.org/10.1016/S0920-5861(96)00120-4
State	Published - Jan 17 1997

Keywords

Carbonaceous
Coke formation
Deactivation
Resonance raman
USY
UV raman spectroscopy
ZSM-5
Zeolites

ASJC Scopus subject areas

Catalysis
Chemistry(all)

Access to Document

10.1016/S0920-5861(96)00120-4

Cite this

@article{fa85008b88ac46038340cafa6992b8aa,

title = "Ultraviolet Raman spectroscopy characterization of coke formation in zeolites",

abstract = "Ultraviolet (UV) Raman spectroscopy has been used to characterize coke formation in ZSM-5 and USY zeolites under propene at temperatures from 300K to 773K. The strong fluorescence background always present with normal Raman spectra is completely avoided in UV Raman spectra. Three groups of UV Raman bands near ~ 1390, ~ 1600 and ~ 3000 cm-1 regions were detected for the two zeolites, and these bands varied significantly at different stages of coke formation. At room temperature, adsorbed propene was formed in the two zeolites and showed similar spectra. At elevated temperatures, the coke formation behavior in the two zeolites is quite different. For example, at 773K the coke species in ZSM-5 are mainly polyolefinic and aromatic species, but poly aromatic and pregraphite species are predominant in USY. The major portion of coke species formed in ZSM-5 can be removed even by He purging at 773K while the coke species in USY are very stable and can only be removed in O2 flow at temperatures above 773K. The difference in coke formation in ZSM-5 and USY is likely due to the different pore structure and acidity of the two zeolites.",

keywords = "Carbonaceous, Coke formation, Deactivation, Resonance raman, USY, UV raman spectroscopy, ZSM-5, Zeolites",

author = "Can Li and Stair, {Peter C.}",

note = "Funding Information: The zeolite samples were kindly provided by Amoco Co. The authors would like to thank Drs. Frank Modica and Jeffrey Miller for their helpful discussion. Acknowledgment is extended to the Donors of the Petroleum Research Fund, administered by the American Chemical Society for partial support of this research. This project was also partially supported by the Center for Catalysis and Surface Science of North-western University.",

year = "1997",

month = jan,

day = "17",

doi = "10.1016/S0920-5861(96)00120-4",

language = "English (US)",

volume = "33",

pages = "353--360",

journal = "Catalysis Today",

issn = "0920-5861",

publisher = "Elsevier",

number = "1-3",

}

TY - JOUR

T1 - Ultraviolet Raman spectroscopy characterization of coke formation in zeolites

AU - Li, Can

AU - Stair, Peter C.

N1 - Funding Information: The zeolite samples were kindly provided by Amoco Co. The authors would like to thank Drs. Frank Modica and Jeffrey Miller for their helpful discussion. Acknowledgment is extended to the Donors of the Petroleum Research Fund, administered by the American Chemical Society for partial support of this research. This project was also partially supported by the Center for Catalysis and Surface Science of North-western University.

PY - 1997/1/17

Y1 - 1997/1/17

N2 - Ultraviolet (UV) Raman spectroscopy has been used to characterize coke formation in ZSM-5 and USY zeolites under propene at temperatures from 300K to 773K. The strong fluorescence background always present with normal Raman spectra is completely avoided in UV Raman spectra. Three groups of UV Raman bands near ~ 1390, ~ 1600 and ~ 3000 cm-1 regions were detected for the two zeolites, and these bands varied significantly at different stages of coke formation. At room temperature, adsorbed propene was formed in the two zeolites and showed similar spectra. At elevated temperatures, the coke formation behavior in the two zeolites is quite different. For example, at 773K the coke species in ZSM-5 are mainly polyolefinic and aromatic species, but poly aromatic and pregraphite species are predominant in USY. The major portion of coke species formed in ZSM-5 can be removed even by He purging at 773K while the coke species in USY are very stable and can only be removed in O2 flow at temperatures above 773K. The difference in coke formation in ZSM-5 and USY is likely due to the different pore structure and acidity of the two zeolites.

AB - Ultraviolet (UV) Raman spectroscopy has been used to characterize coke formation in ZSM-5 and USY zeolites under propene at temperatures from 300K to 773K. The strong fluorescence background always present with normal Raman spectra is completely avoided in UV Raman spectra. Three groups of UV Raman bands near ~ 1390, ~ 1600 and ~ 3000 cm-1 regions were detected for the two zeolites, and these bands varied significantly at different stages of coke formation. At room temperature, adsorbed propene was formed in the two zeolites and showed similar spectra. At elevated temperatures, the coke formation behavior in the two zeolites is quite different. For example, at 773K the coke species in ZSM-5 are mainly polyolefinic and aromatic species, but poly aromatic and pregraphite species are predominant in USY. The major portion of coke species formed in ZSM-5 can be removed even by He purging at 773K while the coke species in USY are very stable and can only be removed in O2 flow at temperatures above 773K. The difference in coke formation in ZSM-5 and USY is likely due to the different pore structure and acidity of the two zeolites.

KW - Carbonaceous

KW - Coke formation

KW - Deactivation

KW - Resonance raman

KW - USY

KW - UV raman spectroscopy

KW - ZSM-5

KW - Zeolites

UR - http://www.scopus.com/inward/record.url?scp=0000229055&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0000229055&partnerID=8YFLogxK

U2 - 10.1016/S0920-5861(96)00120-4

DO - 10.1016/S0920-5861(96)00120-4

M3 - Article

AN - SCOPUS:0000229055

SN - 0920-5861

VL - 33

SP - 353

EP - 360

JO - Catalysis Today

JF - Catalysis Today

IS - 1-3

ER -

Ultraviolet Raman spectroscopy characterization of coke formation in zeolites

Abstract

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this