High efficient mesoporous HZSM-5 nanocatalyst development through desilication with mixed alkaline solution for methanol to olefin reaction

Abstract

Methanol to olefin (MTO) process is a non-oil route for the light olefins production. We report the mesoporous and high siliceous HZSM-5 nanocatalyst development through the new desilication process including the mixed alkaline solution. The properties of nanocatalysts were characterized using TGA/DTA, XRD, ICP, FE-SEM, BET, FT-IR, and NH3-TPD techniques. FE-SEM images represent the spherical morphology of parent nanocatalyst including smooth surface. The XRD analysis confirms that applied desilication does not change the typical MFI-type structure of ZSM-5 nanocatalysts. The BET and NH3-TPD results show that mixed alkaline solution including 40 wt% TPAOH results in the best adjustment of textural (299.7 m2/g) and acidity (strong/weak ratio of 0.21) properties, respectively. The PHZ-NaTP0.4 nanocatalyst represents the highest methanol conversion (99.2%), propylene selectivity (48.3%), C3 =/C2 = molar ratio (7.4) as well as lowest selectivity to C1–C4 alkanes (4.6%) for long time on stream (170 h). The low selectivity of light alkanes (C1–C4) and high total light olefins (ca. 75%) confirm the stable performance of nanocatalyst. Consequently, the developed PHZ-NaTP0.4 nanocatalyst is a high efficient MTO catalyst and can be candidate for commercial scale up.