Selective methylation catalyst, method of catalyst manufacture and methylation process
View Patent ↗Novel catalysts and processes in accordance with the invention can accomplish high selectivity and conversion of naphthalenic compounds such as the conversion of methylnaphthalene (2-MN) or naphthalene to 2,6-dimethylnaphthalene (2,6-DMN). The catalysts are prepared by treating, for example, a ZSM-5-type material with iron in the presence of a halogen such as a fluoride. The resulting catalyst includes iron, as well as a significant portion of aluminum present in the ZSM-5-type starting material. Processes for using the catalysts also are disclosed.
1. A process for preparing an isomorphically substituted zeolitic catalyst comprising the steps of: selecting an aluminosilicate zeolitic material selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-22, MCM-22, ZSM-23, ZSM-39, ZSM-57, mordenite, Beta, FAU, and L-types; and refluxing, in the presence of NH 4 HF 2 , a slurry of the zeolitic material in the presence of a soluble metal compound selected from the group consisting of metal compounds of Fe, Ga, Ti, and Co and mixtures thereof under conditions effective for substituting aluminum in the aluminosilicate zeolitic material with metal from the soluble metal compound to yield a metal to aluminum ratio of between 1:10 and 3:1.
2. A process for preparing an isomorphically substituted zeolitic catalyst comprising the steps of: selecting ZSM-5 aluminosilicate zeolitic material and refluxing, in the presence of NH 4 HF 2 , a slurry of the zeolitic material in the presence of metal fluoride compounds under conditions effective for substituting aluminum in the aluminosilicate zeolitic material with metal from the soluble metal compound to yield a metal to aluminum ratio of between 1:10 and 3:1.