Preparation of SAPO-34 Molecular Sieve Dual Template Using TEA and Morpholine: Influence of Crystallization Times on Catalyst Characteristics and Activity in the MTO Process
Volume 22, Issue 3, Summer 2025, Pages 78-96
https://doi.org/10.22034/ijche.2025.544130.1568
Tayebeh Souri, Mohammad Haghighi, Parisa Sadeghpour, Sogand Aghamohammadi
Abstract Nanostructured SAPO-34 zeolites were synthesized using TEA/morpholine as dual templates through a hydrothermal approach, with the crystallization time as a key parameter. Different characterization methods of XRD, FESEM, EDX-dot mapping, BET, and FTIR were used to analyze these materials. The results demonstrated that the crystallization time was an efficient factor for determining the crystalline phase and uniformity of the final products. Additionally, the size and uniformity of cubic SAPO-34 particles enhanced in longer crystallization times. It was found that the SAPO-34 catalyst synthesized in the crystallization time of 72 h had an optimal distribution of silicon within the crystal lattice structure, resulting in a significant enhancement of its catalytic performance. This catalyst demonstrated the moderately stable production of highly desired olefins, maintaining the selectivity of 58% for ethylene and 38% for propylene over 10 h on stream. The possible reaction mechanism for the MTO process utilizing the prepared SAPO-34 material is proposed.