Selective Isomerization of n-Butane over Mordenite Nanoparticles Fabricated by a Sequential Ball Milling–Recrystallization–Dealumination Route

Abstract

For the first time, a sequential fabrication step involving mechanochemistry, recrystallization, and dealumination was developed to convert low-cost natural zeolites to mordenite (MOR) nanoparticles. Natural zeolites are mostly found having poor textural properties and a high aluminum content, which are not suitable for most industrial catalytic reactions. The parent natural zeolites within the size of 1–10 μm were treated by ball milling to obtain nanosized particles with size in the range of 20–160 nm. The nitrogen physisorption study revealed that the external surface area and intercrystalline mesopore volume of the milled nanoparticles increased by 4- and 7-fold, respectively. Recrystallization by hydrothermal treatment in basic silicate solution was applied to recover the MOR crystallinity at 170 °C for 6 h. The recrystallized MOR samples were further subjected to acid dealumination treatment over different periods. The H-MOR samples were evaluated in a fixed-bed reactor for n-butane isomerization. T...