EMM-17, a New Three-Dimensional Zeolite with Unique 11-Ring Channels and Superior Catalytic Isomerization Performance

Abstract

A new catalytically active zeolite, designated , with a three-dimensional (3D) 11 × 10 × 10-ring topology has been discovered from high throughput experiments while evaluating a family of new organic structure directing agents (OSDAs), 1-alkyl-4-(pyrrolidin-1-yl)pyridin-1-ium hydroxide. The framework structure was determined by model building techniques and confirmed by diffraction calculations. The EMM-17 structure is a random intergrowth of two polymorphs which have a 3D arrangement of intersecting 11 × 10 × 10-ring pores. EMM-17 is stable to calcination to remove the OSDA and can be reproducibly synthesized in the presence of fluoride using common, inexpensive reagents over a wide Si/Al range from 15 to infinity, enabling the catalyst acidity to be tailored to almost any petrochemical application. Unlike OSDAs for many new zeolite structures, the OSDAs for EMM-17 are prepared in one simple alkylation step, making EMM-17 an easy to prepare, highly accessible, catalytically active zeolite. Zeolites containing odd numbered channel sizes are rare, and this is the first confirmed example of a 3D 11-ring aluminosilicate zeolite with a pore size in between those of the commercially important 10-and 12-ring zeolites such as ZSM-5 and Zeolite-Y, respectively. Catalysts prepared from EMM-17 exhibit significantly higher activity for catalytic isomerization with no loss in selectivity than current state of the art catalysts. Catalytic isomerization of linear to branched alkanes is a critical component of commercial dewaxing, allowing for the improvement of cold flow properties of hydrocarbon fuels and lubricants through selective hydroisomerization of normal paraffins.

Machine Learning in the Development of Adsorbents for Clean Energy Application and Greenhouse Gas Capture

“…Likewise, the reproducibility of the computational information should also be guaranteed by providing open access to the data, input and output files, and the software or codes used for computation. [ 223 ] In addition, high throughput experiments promise to generate large quantities of data for specific materials systems, [ 32 , 224 , 225 ] but we stress that experimental data on poorly performing materials are also valuable for training the most robust ML models. [ 40 ] An interesting and very recent development is autonomous laboratories that merge ML techniques with robotics, [ 30 , 128 , 226 , 227 ] where synthesis and characterization are carried out without human intervention.…”

High Throughput Methods in the Synthesis, Characterization, and Optimization of Porous Materials

“…Screening a variety of possible OSDA candidates with HTS has been performed by many authors [54][55][56] as the SDA is an additional degree of freedom when exploring new possible topologies or compositions. A novel example of this is the discovery of the exceptionally low density ITQ-37 zeolite (ITV type).…”

“…[38] Therefore, contemporary HT zeolite work focuses predominantly on a targeting or screening via computational methods prior to synthesis (see Section 3) with novel zeolite discovery through HTS, for example, becoming increasingly infrequent besides a few instances. [39,56] Beyond HTS, HTE focuses on optimization or the benchmarking of catalysts with this avenue similarly involving simulations to pre-screen and flag samples for further investigation. Such developments are to be expected, and indeed welcomed, due to continual increase in computational capabilities coupled with experimental unexplored phase regions increasing in complexity and dimensionality as time increases.…”

EMM-25: The Structure of Two-Dimensional 11 × 10 Medium-Pore Borosilicate Zeolite Unraveled Using 3D Electron Diffraction

“…Among the 15 that have been reported, only five have 11-ring pore windows, which are intermediate in size to medium- and large-pore zeolites. Of the five, JU-64 ( JSR ) and PKU-16 ( POS ) are gallogermanate and germanosilicate, respectively, which are unstable to calcination of the organic structure directing agent (OSDA), and only EMM-17, NU-86, and PST-31 are catalytically active aluminosilicates. − PST-31, however, does not contain 11-membered ring channels. NU-86 was the first aluminosilicate zeolite with a proposed 11-ring channel system, and EMM-17 possesses the framework proposed for NU-86 and can be prepared in all-silica or higher-silica compositions.…”