Methanol conversion to lower olefins over RHO type zeolite

• Phase-pure RHO was synthesized with high BET specific surface area (812 m2 g–1) and acid amount (2.53 mmol g–1).
• H-RHO zeolite was active in the methanol-to-olefins process at 623–723 K with complete initial conversions.
• Highly desired lower olefins were the main product from the methanol conversions.
• Crystalline structure and morphology of the zeolite remained stable after the catalytic tests.

Eight-membered ring small-pore zeolite of RHO-type topology has been synthesized, characterized and tested for methanol-to-olefin (MTO) reaction. The zeolite was hydrothermally crystallized from the gel with Si/Al ratio of 5.0. It showed a high BET specific surface area (812 m2 g–1), micropore volume (0.429 cm3 g–1), and acid amount (2.53 mmol g–1). Scanning electron microscopy observations showed small crystallites of about 1 μm. The zeolite was active for MTO reaction with 100% methanol conversions at 623–723 K, whereas selectivity to lower olefins changed with time.

Methanol conversion over H-RHO at 623 K (triangle), 673 K (cube) and 723 K (diamond).Figure optionsDownload as PowerPoint slide