Effect of selective 4-membered ring dealumination on mordenite-catalyzed dimethyl ether carbonylation
| Autor: | James A. Sawada, Natalia Semagina, Allen A.C. Reule |
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| Rok vydání: | 2017 |
| Předmět: |
Methyl acetate
Inorganic chemistry 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Catalysis Mordenite 0104 chemical sciences chemistry.chemical_compound chemistry Nitric acid Dimethyl ether Leaching (metallurgy) Physical and Theoretical Chemistry 0210 nano-technology Selectivity Carbonylation |
| Zdroj: | Journal of Catalysis. 349:98-109 |
| ISSN: | 0021-9517 |
| Popis: | Dimethyl ether carbonylation to methyl acetate was studied on a series of dealuminated mordenites with Si/Al ratios of 6.5 through 15.4. Dealumination was achieved via leaching with nitric acid. Selective coupled removal of T3 and T4 Al sites located in 4-membered rings in 8- and 12-membered channels, respectively, was suggested by a combination of DRIFTS, TPD of probe molecules, 27 Al MAS NMR, surface area, pore distribution, and XRD analyses. The methyl acetate peak productivity was found to be equal when calculated per residual T3 sites in 8-membered rings, providing experimental evidence of the reaction site specificity. While dealumination led to the decrease in product peak rate because of active and selective T3 site removal, it doubled the catalyst lifetime and increased selectivity upon deactivation from 50% to 80%. The study decoupled the contribution of 4-membered (T3 and T4) and 5-membered (T1 and T2) acid sites to the products’ formation and catalyst deactivation. |
| Databáze: | OpenAIRE |
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