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Summary
The recent research results strongly suggest that a major part of methyl group
decomposition and related side-reactions occur at or near the active sites which
catalyze MCS formation. This is evidenced by the following observations: (a)
formation of Si-H and Si-CH
2
-Si containing products; (b) the co-relation of MeH
suppression and Me2 enhancement when methyl group decomposition is suppressed,
(c) formation of coke near Cu and Cl sites. On a single active site, there is competition
between transferring activated methyl groups to form MCS and decomposing them.
Encouraging methyl group decomposition might increase Si-H containing products.
However, the overall material efficiency should decrease, as more methyl groups will
likely be converted to hydrocarbon wastes. Fine-tuning the balance to achieve the
optimum process performance requires detailed mechanistic information of methyl
group decomposition and its related side-reactions. Studying these side-reactions of
the direct process face the challenge of separating them from the main reaction of
forming MCS. Developing new instrumentation and research methods might be
necessary to achieve this goal.
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