Synthesis of Phosphomolybdate-Based Zeolitic Octahedral Metal Oxide for Methane/Ethane and Methane/Propane Separation

Zeolitic octahedral metal oxide (ZOMO) is interesting for its structure and composition diversity, which make it a good adsorbent for gas separation. This study investigates the synthesis of zeolitic phosphomolybdate and explores the applications of zeolitic phosphomolybdate for methane purification from methane/ethane and methane/propane mixtures. The synthesis conditions have a significant impact on the structure formation and microporosity of the materials, which is studied in detail, shedding light on the formation mechanism of the zeolitic phosphomolybdate framework. The resulting zeolitic phosphomolybdate shows good separation performance for methane/ethane and methane/propane separation. The microporosity of zeolitic phosphomolybdate was modified by organic ammonium cation exchange, which further improved the separation performance. The zeolitic phosphomolybdate can be easily regenerated and reused several times.