An efficient, rapid, and non-centrifugation synthesis of nanosized zeolites by accelerating the nucleation rate

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 6; no. 42; pp. 21156 - 21161
• Main Authors: Zhang, Changsheng, Wu, Qinming, Lei, Chi, Han, Shichao, Zhu, Qiuyan, Maurer, Stefan, Dai, Daniel, Parvulescu, Andrei-Nicolae, Müller, Ulrich, Meng, Xiangju, Xiao, Feng-Shou
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 30.10.2018
• Subjects: activation energy; Alkenes; Aluminum; catalysts; catalytic activity; Catalytic converters; Centrifugation; Chemical reactions; Chemical synthesis; Crystals; Gels; Mass transfer; methanol; Nucleation; silica; silicon; Silicon dioxide; Solvents; Water consumption; Zeolites
• ISSN: 2050-7488; 2050-7496; 2050-7496
• DOI: 10.1039/C8TA07171C

Access to nanosized zeolites is a topical subject due to the advantageous mass transfer in zeolite catalyzed reactions. Herein we report a low-cost and generalized methodology to decrease zeolite crystal sizes by accelerating the nucleation rate when reducing the solvent amount in the synthesis. As anticipated, nanosized zeolites like MFI (100–200 nm, Si/Al ratios from 100 to ∞ in the starting gels) and BEA (50–200 nm, Si/Al ratio of 13) have been successfully synthesized with a H 2 O/SiO 2 ratio of 2.0–3.0. The lower consumption of water as the solvent in the synthesis leads to non-centrifugation for nanosized zeolites, giving higher yields of the zeolite product. Experimental data confirm lower apparent activation energy for nucleation at higher gel concentrations in the synthesis of ZSM-5 zeolites. Catalytic examination of the conversion of methanol to olefins (MTO) demonstrates that the thus-obtained nanosized ZSM-5 zeolite (NS-ZSM-5) exhibits a much longer catalyst lifetime than conventional ZSM-5 (C-ZSM-5) and even nanosized ZSM-5 crystals (NC-ZSM-5) obtained from a hydrothermal route.