Source abstract
Abstract
The present study reports the unbiased chemical etching of micron-sized ZSM-5 crystals with an NH4F solution, resulting in house-of-cards-like single crystals containing large rectangular cavities surrounded by thin (15–30 nm), flat, and highly crystalline walls. The formation of such house-of-cards-like architecture is a result of the preferential extraction of misoriented nanocrystalline domains followed by the uniform dissolution of the remaining part of the crystal. The characteristic features of NH4F-treated zeolites are the retention of framework composition (Si/Al) and Brønsted acidity, high crystallinity, a moderate increase in the external surface area, and increased accessibility to their active sites. Such a combination produces zeolite catalysts with superior performances (activity, stability, and coke resistance) in the ethanol-to-hydrocarbon conversion. The physicochemical properties of this newly engineered zeolite are compared to those of a hierarchical zeolite obtained by caustic leaching and zeolite nanosheets synthesized with a bifunctional template, a diquaternary ammonium-type surfactant.
Source: openalex_inverted_index · Quality: baseline
Affiliations
State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, China University of Petroleum (East China), 266580 Qingdao, China
Institut de Chimie des Milieux et Matériaux de Poitiers (ICM2P), UMR 7285 CNRS, 4 Rue Michel Brunet, Bâtiment B27, 86073 Poitiers Cedex, France
Université de Haute Alsace (UHA), Université de Strasbourg (UDS), Axe Matériaux à Porosité Contrôlée (MPC), Institut de Science des Matériaux de Mulhouse (IS2M), UMR CNRS 7361, ENSCMu, 3 bis rue Alfred Werner, F-68093 Mulhouse, France
Institut de Physique et de Chimie de Strasbourg, Université de Strasbourg 23, rue du Loess BP 43, F-67034 Strasbourg, France
SEM Application Team, JEOL Ltd., Akisima, Tokyo 196-8558, Japan
Laboratoire Catalyse et Spectrochimie, Normandie Univ, ENSICAEN, UN ICAEN, CNRS, 6 Boulevard Maréchal Juin, 14050 Caen, France
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, 130012 Changchun, China
Funding
Ministry of Education of the People's Republic of China · National Natural Science Foundation of China · China University of Petroleum, Beijing · Sino-French International Associated Laboratory
References (55)
Show source-provided references
19. Young, D. A. Hydrocarbon conversion process and catalyst comprising a crystalline alumino-silicate leached with sodium hydroxide. U.S. Patent US3326797, assigned to Unocal, 1964.
20. Gilson, J.P.; Nanne, J. M.; Den Otter, G. J. Process for Isomerizing Hydrocarbons. EP Patent EP0398416, assigned to Shell, 1989.
26. Valtchev, V.; Gilson, J.P.; Qin, Z. Method for the Preparation of Synthetic Crystalline Zeolite Materials with Enhanced Total Pore Volume. WO Patent WO2016005783A1, assigned to CNRS, 2016.
27. Breck, D. W.; Skeels, G. W. Silicon substituted zeolite compositions and process for preparing same. U.S. Patent US4503023, assigned to Union Carbide, 1985.
28. Skeels, G. W.; Breck, D. W. In Proceedings of the Sixth International Zeolite Conference, Olson, D., Olson, D., Bisio, A., Eds. Butterworths: Guildford, U.K., 1984; p 87.