A Complex Zeolite Containing Multiple Ring Sizes in a Single Channel: One‐Dimensional Zeolite UZM‐55

Abstract

Zeolites are porous aluminosilicate materials utilized in a variety of sorption, separation, and catalytic applications. The oil refining industry in particular has seen a number of significant advances due to the introduction of new technologies enabled by new zeolites. Of particular importance are zeolites with 10‐ or 12‐membered ring pores, resulting in pore shapes and sizes appropriate for the interaction with small hydrocarbon molecules. Here, the synthesis of a new zeolite UZM‐55 is reported and the idealized structure thereof is presented. The most complex structure solved to date, UZM‐55 possesses a large triclinic unit cell containing 52 T‐sites. The material uniquely contains both 10‐ and 12‐membered ring pores in a single, undulating one‐dimensional channel, the first example in a zeolitic material of multiple delimiting rings in a single channel. This discovery opens new opportunities in shape‐selective adsorption and catalysis. Demonstrated here is the unique adsorption behavior of UZM‐55, shown both experimentally and computationally to adsorb one nonane molecule per unit cell in a linear conformation.

An Aluminosilicate Zeolite Containing Rings of Tetrahedral Atoms with All Odd Numbers from Five to Eleven

“…As such, they have the ring sequence 9‐11‐10‐11‐9‐10 and are thus undulating in nature. This feature is particularly intriguing because the pure‐silica UZM‐55 is the only example of the existence among all zeolite structures of multiple delimiting rings (10‐ and 12‐rings) in a single channel [13] . The framework density (defined as the number of T‐atoms per 1000 Å 3 ) of PST‐31 was calculated to be 18.0.…”

An Aluminosilicate Zeolite Containing Rings of Tetrahedral Atoms with All Odd Numbers from Five to Eleven

“…Field emission scanning electron microscopy shows that as-synthesized PST-31 always appears as very small (< 30 nm) nanospheres ( Figure S1), regardless of the type and amount of alkali cations employed in its synthesis. 13 Cm agic-anglespinning (MAS) nuclear magnetic resonance (NMR) spectroscopy reveals that its OSDAm olecules remain intact ( Figure S2). When PST-31 was calcined at 600 8 8Ct or emove the occluded OSDAs ( Figure S3) and then converted to its proton form (H-PST-31), there were no significant changes in the powder X-ray diffraction (PXRD) pattern (Figure 1a), indicating its high structural stability.However,while the 27 Al MAS NMR spectrum of as-synthesized PST-31 shows one resonance around 55 ppm assigned to tetrahedral Al, an additional weak signal around 0ppm due to octahedral Al is observable in the spectrum of H-PST-31 ( Figure S4).…”

“…ing because the pure-silica UZM-55 is the only example of the existence among all zeolite structures of multiple delimiting rings (10-and 12-rings) in asingle channel. [13] Theframework density (defined as the number of T-atoms per 1000 3 )o f PST-31 was calculated to be 18.0.…”

Revival of Zeolite‐Templated Nanocarbon Materials: Recent Advances in Energy Storage and Conversion

“…), [121] 2) 1D channel of zeolites (AEL, AFI, LTL, etc. ), [122,123] 3) 2D channel of zeolites (HEU, IWT, MWW, etc. ), [124,125] and 4) 3D channel of zeolites (CHA, BEA, etc.).…”