Isomerization of n-butene to isobutene by ferrierite and modified ferrierite catalysts

Journal Article · Fri Dec 01 04:00:00 EST 1995 · Journal of Catalysis

DOI:https://doi.org/10.1006/jcat.1995.1308· OSTI ID:224013

Pellet, R J; Casey, D G; Huang, H M ^[1]

---

1. Texaco Group, Inc., Beacon, NY (United States); and others

n-Butene was isomerized to isobutene over fresh and used ferrierite catalysts. Activity and selectivity for skeletal isomerization and biproduct formation were measured and changes following extended use were related to changes in ferrierite`s aluminum distribution. MAS-NMR of the deactivated catalyst showed a decrease in zeolitic, tetrahedral aluminum and an increase in octahedral aluminum. In order to understand changes occurring following extended use, ferrierite powders were modified by steam and by steam plus acid-wash treatments. A steamed-acid-washed ferrierite catalyst also exhibited reduced initial n-butene conversion but high isobutene selectivity throughout the run. Biproduct formation was greatly reduced. Characterization indicated that acid-wash treatment after steaming had no effect on framework aluminum but partially reduced the amount of nonframework aluminum. Steamed-acid-washed ferrierite was much less sensitive to subsequent hydrothermal treatments than was the starting ferrierite. The study suggests a catalytic role for nonframework alumina, generated upon extended use of unmodified ferrierite and present in steamed ferrierite. Catalytically active, nonframework sites contribute to the production of non-C{sub 4} products and reduced isobutene selectivity. Steamed-acid-washed ferrierite with the active nonframe-work phase removed exhibits excellent isobutene selectivity and catalytic stability. 29 refs., 11 figs., 4 tabs.

• OSTI ID: 224013
• Journal Information: Journal of Catalysis, Journal Name: Journal of Catalysis Journal Issue: 2 Vol. 157; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
40 CHEMISTRY
ALUMINIUM COMPOUNDS
BUTENES
CATALYSTS
CATALYTIC EFFECTS
IRON COMPOUNDS
ISOMERIZATION
ZEOLITES