Shape-selective Fe-MFI catalyst for synthesis of 2,6-dimethylnaphthalene by methylation with methanol

The present study deals with shape-selective methylation of naphthalene for synthesis of 2,6-dimethylnaphthalene (2,6-DMN), and focuses on the Fe-MFI (Fe-ZSM-5) catalyst prepared by isomorphous substitution using Fe compounds and ZSM-5, which led to a highly shape-selective catalyst formulation for 2,6-DMN synthesis. Results with modified ZSM-5 by isomorphous substitution with Ti and Co, by ion exchange with Fe as well as acid treatment of ZSM-5 are also shown for comparison. The best Fe-ZSM-5 formulations used under suitable conditions can lead to shape-selective methylation of naphthalene with methanol, with the 2,6-/2,7-DMN ratio and 2,6-DMN/DMNs percentage reaching as high as 2.2 and about 60%, respectively.