Facile control of crystallite size of ZSM-5 catalyst for cracking of hexane

Nano-sized H-ZSM-5 (ca. ∼65 nm) was successfully prepared by mixing the mother gel under mild conditions before crystallization. Furthermore, a facile control of the crystallite size of the H-ZSM-5 catalyst was achieved merely by changing the amount of water in the mother gel. Three different-sized H-ZSM-5 catalysts were used as a catalyst for hexane cracking at 723–923 K. The crystallite size of H-ZSM-5 little affected the initial activity, but affected the deactivation rate considerably. The reduction in the crystallite size of the H-ZSM-5 catalysts contributes to the slow deactivation, probably because the H-ZSM-5 with a smaller crystallite size is less sensitive to deactivation by pore blocking by coke formed.

Graphical abstractNano-sized H-ZSM-5 (ca. ∼65 nm) was synthesized by mixing the mother gel under mild conditions before crystallization. A facile control of the crystallite size of the H-ZSM-5 catalyst was achieved merely by changing the amount of water in the mother gel. The reduction in the crystallite size of the ZSM-5 catalysts suppressed the formation of coke on the surface and/or in the pore, resulting in the slow deactivation.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Nano-sized H-ZSM-5 (ca. ∼65 nm) was synthesized. ► The particle size of ZSM-5 was controlled by changing the amount of water. ► The reduction in the crystallite size of ZSM-5 suppressed the formation of coke.