Effect of template combinations (TEA/MOR, TEA/DEA, DEA/MOR) in synthesis of nanostructured CoAPSO-34 catalyst used in conversion of methanol to light olefins

• Successful implementation of mixed templates in nanostructured CoSAPO-34 synthesis.
• Nature of the mixed templates determines the morphology of final product.
• DEA/Morpholine mixed template reflects high performance in MTO process.
• Si incorporation was the highest for the catalyst prepared with DEA/morpholine.

Current research was focused on the synthesis of CoAPSO-34 catalysts with various templates combination with the aim of reducing the preparation cost and implemented in methanol conversion to light olefins reaction. Three sets of mixed templates are taken into account for CoAPSO-34 synthesis, being TEA/morpholine, TEA/DEA and DEA/morpholine with constant composition of 50%:50%. The catalysts were prepared via hydrothermal method and characterized with XRD, FESEM, PDS, EDX, BET, FTIR and NH3-TPD techniques. Nanostructured catalyst synthesized with DEA/morpholine mixture exhibited the highest crystallinity evidenced by XRD analysis. The catalyst prepared with TEA/DEA mixed template has the smallest particle size and the most uniform particle size distribution. The highest value of Si incorporation was obtained for the catalyst prepared with DEA/morpholine mixture shown by EDX analysis. Methanol to light olefins reaction was carried out at different reaction temperatures. The stability test was conducted maintaining at constant temperature, molar feed ratio and GHSV to distinguish the effect of time on stream. In comparison, later emergence of DME in the products stream for the catalyst prepared with DEA/morpholine can be due to its higher crystallinity, specific surface area, better Si distribution and higher structural OH bands evidenced by XRD, BET, EDX and FTIR techniques, respectively.

Applying mixed templates resulted in enhancement of catalyst life time and simultaneously causing the reduction in catalyst preparation costs compared to those prepared with single template. Methanol conversion to light olefins was investigated over SAPO-34 catalysts with Co introduction exploring the effect of different mixed templates. Three sets of mixed templates are taken into account for CoAPSO-34 synthesis, being TEA/morpholine, TEA/DEA and DEA/morpholine with constant composition of 50%:50%. The catalysts were prepared via hydrothermal method and characterized with XRD, FESEM, EDX dot-mapping, BET, FTIR and NH3-TPD techniques. Application of DEA/morpholine mixed template resulted in higher dispersion of Si.Figure optionsDownload as PowerPoint slide