摘要 |
Provided are catalyst composites useful for the production of olefins during a metathesis reaction, as well as methods of making and using the same. Certain methods comprise a support comprising at least about 90% by weight silica; and an eggshell layer on the support comprising about 0.25 to about 10 wt. % tungsten in the form of tungsten oxide or tungsten oxide hydrate, based on the total weight of the catalyst composite. |