The direct synthesis of methylchlorosilanes. 1. Steady-state and transient reaction kinetics

Journal Article · Sun Mar 01 04:00:00 EST 1992 · Journal of Catalysis; (United States)

OSTI ID:7202906

Rethwisch, D G ^[1]

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1. Univ. of Iowa, Iowa City (United States)

Reaction kinetics under steady-state and transient conditions were used to study the effects of the catalyst (copper) and promoters (zinc and tin) on the direct reaction of methyl chloride with silicon to produce methylchlorosilanes. Use of infrared spectroscopy allowed rapid analysis of the gas-phase product composition. This allowed the accurate measurement of the apparent activation energy and the apparent reaction order for each product. An improved method for calculating direct reaction rates is also introduced. Addition of Zn as a promoter to Cu did not change the overall reaction rate but increased the selectivity for more methylated silanes. Tin promotion increased the selectivity for more chlorinated silanes, while having little effect on the overall reaction rate. Copromotion with zinc and tin increased the overall reaction rate; however, the selectivity for dimethyldichlorosilane (DMDC) was dependent on the concentration of tim. A trace amount of tin (ca. 0.005-0.01 wt%) produced the highest selectivity for DMDC; however, increasing the amount of tin to 0.2 wt% decreased the selectivity. The authors propose that the primary role of zinc is to direct the dissociative adsorption of MeCl such that the methyl group is attached to the Si, and the Cl group is attached to the Zn.

• OSTI ID: 7202906
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 134:1; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
ACTIVATION ENERGY
ADSORPTION
CATALYSIS
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHLORINATED ALIPHATIC HYDROCARBONS
COPPER
DISSOCIATION
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY
HALOGENATED ALIPHATIC HYDROCARBONS
HYDRIDES
HYDROGEN COMPOUNDS
INFRARED RADIATION
KINETICS
METALS
METHYL CHLORIDE
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC SILICON COMPOUNDS
PERFORMANCE
PROMOTERS
QUANTITY RATIO
RADIATIONS
REACTION KINETICS
SEMIMETALS
SILANES
SILICON
SILICON COMPOUNDS
SORPTION
SPECTROSCOPY
STEADY-STATE CONDITIONS
SYNTHESIS
TIN
TRACE AMOUNTS
TRANSIENTS
TRANSITION ELEMENTS
ZINC