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• Seed-derived ferrierite (FER) without any organic structure-directing agent (OSDA) showed a higher activity and stability. • Optimal amount of commercial FER-seed (15 wt%FER) stabilized Brønsted acidic sites. • Less formation of coke precursors was obserbed by decreasing Lewis acidic EFAL defect sites. The seed-derived ferrierite zeolite (FER) synthesized at different contents of FER seed component without using any organic structure-directing agent (OSDA) showed a higher catalytic activity and stability for a gas-phase carbonylation of dimethyl ether (DME) to methyl acetate (MA) at an optimal amount of the previously synthesized FER-seed with 15wt%. The optimal amount of FER-seed material played an important role to optimize the numbers of active Brønsted acid sites in 8-membered ring (8-MR) channels with less formation of coke precursors by decreasing defect sites through their recrystallization during the preparation step. The defected Lewis acidic extra-framework aluminum (EFAL) sites on the seed-derived FER surfaces were responsible for preferential coke depositions and for a retarded CO insertion by decreasing the rate of the gas-phase DME carbonylation reaction. [ABSTRACT FROM AUTHOR]

An indirect ethanol synthesis in terms of carbon neutral strategy by consuming synthesis gas consists of three separate steps such as syngas to dimethyl ether (DME), DME carbonylation and methyl acetate (MA) hydrogenation through tandem reactions. For the series reactions, the nanosheet ferrierite (FER) zeolite was used for a gas-phase DME carbonylation reaction to MA and the Cu-ZnO-Al 2 O 3 (CZA)-based catalyst was modified with additional metal oxide promoter (M = Ga, In and Nd) for MA hydrogenation, where the CZA-M catalysts were prepared by a simple coprecipitation method. The CZA-M catalysts hybridized with FER zeolite showed different catalytic activity for the tandem reactions, where the catalytic activity was largely affected by the CZA-M surface properties. The effects of additional metal oxides promoter on the CZA-M were carefully investigated and the CZA-Nd catalyst having larger Cu crystallites showed the best catalytic activity due to the enhanced oxygen vacant sites correspond to their basic sites. [Display omitted] • Direct ethanol synthesis was verified by successive carbonylation and hydrogenation. • FER zeolite hybridized with Cu-ZnO-Al 2 O 3 -Nd revealed a higher ethanol yield. • Larger Cu+ sites and Bronsted acid sites were to enhance catalytic activity and stability. [ABSTRACT FROM AUTHOR]

Different distributions and locations of coke precursors on the highly crystalline seed-derived ferrierite (FER) altered the catalytic stability during carbonylation of dimethyl ether (DME) in a gas-phase. The larger amounts of heavy cokes on external Brønsted acidic sites of the FER were responsible for a fast deactivation, and their distributions on the active internal Brønsted acid sites such as 8-membered ring (8-MR) channels were largely affected by their crystallinity. Although the surface cokes on the FERs were inevitably formed, the FER having an optimal Brønsted acid site concentration in its 8-MR channels which were formed by recrystallization of Lewis acidic extra-framework Al species during a seed-assisted OSDA-free synthesis step, revealed slower deactivation rate at the proper seed content in the range of 7–15 wt%. The slow deactivation phenomena on the seed-derived crystalline FERs, especially on the optimal FER(S15) and FER(S7) having the proper amount of crystallization sites were originated by minimizing the coke depositions on the external surfaces. Image 1 • Deactivations for gas-phase DME carbonylation were altered according to coke distributions. • Amount of Brønsted acid sites in 8-MR channels was linearly correlated with crystallinity and activity. • Extent of external cokes was more important for catalyst deactivation compared to internal cokes. • Simple recrystallization method by seed-assisted OSDA-free synthesis was effective to adjust defect sites. [ABSTRACT FROM AUTHOR]

Tandemly coupled gas-phase CO 2 hydrogenation reaction to dimethyl ether (DME) with its successive carbonylation (CO insertion) for one-step methyl acetate (MA) synthesis was investigated on newly designed SiO 2 -encapsulated Cu-ZnO nanoparticles (CZ@Si) hybridized with nano-sized Ferrierite (NFER) zeolite. The core-shell-structured CZ@Si with thermally stabilized Cu-ZnO nanoparticles having stronger Cu-O-Si interfaces was crucial to form an optimal CO/DME ratio, which was found to be a key step to switch the reaction pathway from methanol-mediate hydrocarbon formation route to carbonylation route to selectively synthesize oxygenates by CO 2 hydrogenation-initiated tandemly coupled reaction. The formed methanol intermediate was further reacted to form DME by methanol dehydration, and the rates of surface methoxy formation and CO insertion to form acetyl intermediate were enhanced with the increased Brønsted acid sites in 8-membered ring channels on the NFER with higher MA selectivity of ∼50% through novel tandem reaction for efficient CO 2 utilization. [Display omitted] • Tandemly coupled CO 2 hydrogenation to direct methyl acetate synthesis was investigated. • SiO 2 -encapsulated Cu-ZnO nanoparticles was well hybridized with nano-sized ferrierite. • CO 2 hydrogenation-initiated DME carbonylation revealed higher MA selectivity of ∼50%. [ABSTRACT FROM AUTHOR]

• DME carbonylation is conducted in fluidized bed reactor to enhance the methyl acetate productivity. • Parametric studies on operating conditions were conducted for process optimization. • Optimized MA production can effectively bring economic and environmental benefits through the TEA and LCA. The carbonylation of bio-based dimethyl ether (DME) using ferrierite offers a renewable approach to methyl acetate (MA) production with a potential reduction in carbon emissions. This work showcases the feasibility of employing fluidized-bed reactors in this process, leveraging benefits such as effective solid mixing, uniform temperature distribution, and facile catalyst purge and makeup. Through parametric studies, the impact of operating conditions on the reaction kinetics and reactor hydrodynamics was elucidated. Both physical and chemical catalyst deactivation were found to be dependent on the fluidization regime. Numerical models based on experimental results enabled the prediction of reaction yield and selectivity in the process simulation and optimization. Preliminary techno-economic analysis (TEA) and life cycle assessment (LCA) showed the potential for a 40% reduction in production costs and an 8% reduction in the global warming potential compared to the fossil-based benchmark. Overall, this study highlights the operation simplicity, cost competitiveness, and environmental benefit of MA production from DME carbonylation in a fluidized-bed reactor, providing insights for process scale-up and feedstock sourcing. [ABSTRACT FROM AUTHOR]