Dimethyl Ether to Olefins on Hybrid Intergrowth Structure Zeolites

Abstract

A series of catalysts based on hybrid intergrowth structure zeolites MFI-MEL, MFI-MTW, and MFI-MCM-41 are studied in the reaction of olefins synthesis from dimethyl ether at atmospheric pressure and a temperature of 340 °C. The total acidity of hybrid zeolite-based catalysts is shown to correlate with their activity. However, the use of zeolite with the structure MFI-MCM-41, which is characterized by a high content of medium acid sites, additionally catalyzes the methanol dehydration reaction, resulting in a decrease in the observed DME conversion. The obtained product distributions are brought into correlation with the texture of catalysts. It is shown that the use of hybrid zeolites does not change the mechanism of reaction, but the structural features of zeolites influence the priority of the competing MTO reactions: high ethylene yield is observed for catalysts with high micropore volume. The topology of the hybrid zeolite has been shown to influence the hydrogen transfer reaction rate, but not to change the isomerizing activity of the catalyst.

High value-added fuel additive production from waste bio-glycerol over a versatile nanohybrid catalyst

“…This substantial enhancement in acidic sites within the MAZ nanohybrid is attributed to the contribution of TO–Mg–OH (T = Si, Al), AlO + species, and extra-framework Al species originating from MA. 39,43–45 This aspect is further supported by 27 Al NMR spectroscopy. In the MZ sample, the total acidity decreases (0.08 mmol g −1 ) as compared to the bare Z sample (0.14 mmol g −1 ), and this can be attributed to the exchange of Mg 2+ and the capping of the acid sites of Z with the solid basic MgO species.…”

“…51 Intensities of peaks centered at about 260 nm and 400 nm decrease for the MAZ catalyst compared to Z, indicating an interaction between MA and Z. 45 XPS analysis was conducted for the MAZ sample, and the obtained results are depicted in Fig. 4.…”

Statistical analysis and optimization for direct dimethyl ether synthesis from syngas over CuO–ZnO–Al2O3/γ-Al2O3 bifunctional catalysts

“…It is also considered as a potential candidate for solvent-aided recovery processes (Aldalawy et al 2023;Sadeghi Yamchi et al 2020). The high potential of DME as a beneficial chemical intermediate has received much attention for the production of many chemicals such as methyl acetate (Sung et al 2023), and light olefins (Magomedova et al 2023). Moreover, DME has been emerged as an intermediate for diesel fuel used in compression ignition engines because of its high cetane number (Arias et al 2023).…”