Isomorphous substitution of zeolites and particle size determination of cobalt clusters in zeolites

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:6914864

Nam, S S

An increasing demand for new energy sources and efforts to cleanup the environment have created a renewed interest in zeolite science and technology. In the fields of catalytic science and research, zeolites have been widely used as catalysts or supports for metals due to their shape-selective character, high surface area, acidic nature, and well-defined structure. The purpose of this research is the preparation, characterization, and application of newly developed, modified or improved zeolites. The first part of the thesis presents synthesis, characterization, and testing of isomorphously substituted ZSM-5 and ZSM-11 zeolites. These materials are useful in the transformation of low olefins to environmentally and commercially useful products such as branched olefins, aromatics or gasoline range distillates. The incorporation of catalytically active species such boron, iron, and gallium into zeolites significantly changes the acidic character and zeolite structure, thereby changing catalytic properties. New synthetic methodologies were introduced and unique characterization methods such as calcination, rehydration and deuteration, and ion-exchange were developed to study isomorphously substituted zeolite structures. Optical and magnetic spectroscopy techniques have been used to study the distribution of isomorphous cations in zeolites. These studies suggest that three different species tetrahedrally coordinated framework species, defeat species, and extraframework oxide species exist in these materials. These isomorphously substituted zeolites were tested as catalysts for upgrading of olefins via oligomerization to gasoline range distillates. In this context, the volatile fraction of gasoline hydrocarbons such as volatile linear olefins may be removed and transformed into less volatile commercially useful products in order to improve air quality. The second part presents data on preparation, characterization, and applications of small metal particles in zeolites.

• Research Organization: Connecticut Univ., Storrs, CT (United States)
• OSTI ID: 6914864
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601 -- Other Materials-- Preparation & Manufacture
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKENES
CATALYSTS
CHEMICAL PREPARATION
CHEMICAL REACTIONS
DERIVATIZATION
DISTILLATES
ENERGY SOURCES
FOSSIL FUELS
FUELS
HYDROCARBONS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
MINERALS
ORGANIC COMPOUNDS
PETROLEUM
PETROLEUM DISTILLATES
PETROLEUM FRACTIONS
POLYMERIZATION
SILICATE MINERALS
SYNTHESIS
ZEOLITES