SSZ‐53 and SSZ‐59: Two Novel Extra‐Large Pore Zeolites

Abstract

The syntheses, structure solutions, and physicochemical and catalytic characterizations of the novel zeolites SSZ-53 and SSZ-59 are described. SSZ-53 and SSZ-59 were synthesized under hydrothermal conditions with the [1-(4-fluorophenyl)cyclopentylmethyl]trimethyl ammonium cation and 1-[1-(4-chlorophenyl)cyclopentylmethyl]-1-methyl azocanium cation, respectively, as structure-directing agents. The framework topology of SSZ-53 was solved with the FOCUS method, and the structure of SSZ-59 was determined by model building. Rietveld refinement of synchrotron X-ray powder diffraction data confirms each proposed model. SSZ-53 and SSZ-59 each possess a one-dimensional channel system delimited by 14-membered rings. Results from transmission electron microscopy, electron diffraction, catalytic experiments (spaciousness index and constraint index tests), and argon and hydrocarbon adsorption experiments are consistent with the proposed structures.

Supra-molecular assembly of aromatic proton sponges to direct the crystallization of extra-large-pore zeotypes

“…Using large and rigid OSDAs, different extra-large-pore zeolites presenting mono-directional 14-ring channels [3][4][5], multi-dimensional extra-large channels [6,7] and even mesoporous zeolites [8,9] have been synthesized. In these cases, the zeolite crystallization occurs through the interaction of single organic molecular units with the inorganic sources present in the synthesis gel.…”

Phase-Transformation Synthesis of SAPO-34 and a Novel SAPO Molecular Sieve with RHO Framework Type from a SAPO-5 Precursor

“…Therefore, novel materials and new synthesis methodologies are always the interesting topics in the field of molecular sieves. [4][5][6][7][8] Molecular sieves are normally synthesized under hydrothermal condition using amorphous gel as the starting material. However, it is sometimes found that the crystallization of one molecular sieve phase is followed by in situ transformation into another phase.…”

Catalytic Properties of Hierarchical Mesoporous Zeolites Templated with a Mixture of Small Organic Ammonium Salts and Mesoscale Cationic Polymers

“…[1,2] [19]). However, the use of these materials is rather limited owing to the difficult separation of nanosized zeolite crystals from the reaction mixture,[3] the complexity of the templates used for the synthesis of ultralarge-pore zeolites, [6][7][8][9] and the relatively low thermal and hydrothermal stability of ordered mesoporous materials. [17][18][19][20][21][22][23][24][25][26][27][28] More recently, mesoporous zeolites from nanosized carbon templates have also been successfully synthesized, [29][30][31][32] but their industrial applications are still limited by the complexity of the synthetic procedure involved and the hydrophobicity of the carbon templates.…”

“…However, relatively small individual micropores in zeolites such as Beta, ZSM-5, and Y strongly influence mass transport to and from the active sites located within them, severely limiting the performance of industrial catalysts. [1,2] To overcome this problem, various strategies have been successfully pursued, such as the synthesis of nanosized zeolites, [3] ultralarge-pore zeolites and zeolite analogues (VPI-5, [4] JDF-20, [5] UTD-1, [6,7] CIT-5, [8] SSZ-53, [9] ECR-34, [10] UCSB, [11] ITQ-21, [12] IM-12, [13] and SU-M, [14,15] among others), and ordered mesoporous materials (e.g. MCM-41, [17] SBA-15, [18] and FSM-16, [19]).…”