Stable boron-modified ZSM-22 zeolite catalyst for selective production of propylene from methanol

The effects of boron incorporation on the ZSM-22 particle size, morphology, and acidity were investigated via a microwave-assisted synthesis method (MAHyS). The in situ addition of boron into the TON framework resulted in ZSM-22 zeolite (TON framework) with the same needle-shape morphology but smaller particles size as observed from the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images. The incorporation of boron into ZSM-22 zeolite resulted in enhanced textural properties as indicated by N adsorption-desorption measurements. The temperature-programmed desorption of ammonia (NH-TPD) analysis showed insignificant changes in the acidity properties, while pyridine Fourier-transform infrared (FTIR) analysis showed a slight enhancement in the boron-incorporated ZSM-22 zeolite acidity. The boron-incorporated ZSM-22 zeolite sample showed extended catalytic activity in methanol conversion to light olefins