used to enhance the performance of commercial catalysts, with the promise of becoming a generalized platform for the rational design of zeolites across a broad range of framework types.

Zeolite-based catalysts are globally employed in many industrial processes, such as in crude-oil refining and in the production of bulk chemicals. However, to be implemented in industrial reactors efficiently, zeolite powders are required to be shaped in catalyst bodies. Scale-up of zeolite catalysts into such forms comes with side effects to its overall physicochemical properties and to those of its constituting components. Although fundamental research into “technical” solid catalysts is scarce, binder effects have been reported to significantly impact their catalytic properties and lifetime. Given the large number of additional (in)­organic components added in the formulation, it is somehow surprising to see that there is a distinct lack of research into the unintentional impact organic additives can have on the properties of the zeolite and the catalyst bodies in general. Here, we systematically prepared a series of alumina-bound zeolite ZSM-5-based catalyst bodies, with organic additives such as peptizing, plasticizing, and lubricating agents, to rationalize their impacts on the physicochemical properties of the shaped catalyst bodies. By utilizing a carefully selected arsenal of bulk and high-spatial resolution multiscale characterization techniques, as well as specifically sized bioinspired fluorescent nanoprobes to study pore accessibility, we clearly show that, although the organic additives achieve their primary function of a mechanically robust material, uncontrolled processes are taking place in parallel. We reveal that the extrusion process can lead to zeolite dealumination (from acid peptizing treatment, and localized steaming upon calcination); meso- and macropore structural rearrangement (via burning-out of organic plasticizing and lubricating agents upon calcination); and abating of known alumina binder effects (via scavenging of Al species via chelating lubricating agents), which significantly impact catalytic performance. Understanding the mechanisms behind such effects in industrial-grade catalyst formulations can lead to enhanced design of these important materials, which can improve process efficiency in a vast range of industrial catalytic reactions.

Understanding the formation of carbon deposits in zeolites is vital to developing new,s uperior materials for various applications,i ncluding oil and gas conversion processes.H erein, atom probe tomography (APT) has been used to spatially resolve the 3D compositional changes at the subnm length scale in as ingle zeolite ZSM-5 crystal, whichh as been partially deactivated by the methanol-to-hydrocarbons reaction using 13 C-labeled methanol. The results reveal the formation of coke in agglomerates that span length scales from tens of nanometers to atomic clusters with amedian size of 30-60 13 Ca toms.T hese clusters correlate with local increases in Brønsted acid site density,demonstrating that the formation of the first deactivating coke precursor molecules occurs in nanoscopic regions enriched in aluminum. This nanoscale correlation underscores the importance of carefully engineering materials to suppress detrimental coke formation.Zeolites are crystalline,m icroporous materials that exhibit robust hydrothermal stability,allowing them to be used under demanding process conditions,s uch as oil refinery operations [1,2] and automotive emissions treatments. [3,4] Commercially,one of the most important zeolites is ZSM-5 with MFI framework topology,w hich has become ubiquitous in petroleum refining and chemical manufacturing.[2] Thee normous quantities at which this material is utilized at the global scale continue to drive research targeting improved performance. Thed etrimental formation of coke is one of the factors limiting zeolite materials,p articularly ZSM-5, in highdemand catalytic processes,s uch as fluid catalytic cracking (FCC) and the methanol-to-hydrocarbons (MTH) reaction. ZSM-5 coking in the MTH reaction has long been studied, with ar ange of conclusions regarding the nature and mechanism of coke formation. [5,6] Despite ongoing investigations and debates,there is aconsensus that coking occurs due to the formation of alkylated mono-and polycyclic aromatics near internal channel intersections,followed by an increase in surface coke from polycyclica renes near pore openings, which finally form agraphitic layer and block pore access. [7][8][9][10][11][12][13] In order to more fully elucidate the material properties that promote the detrimental formation of coke during the MTH reaction on ZSM-5, it would be beneficial to study the carbon deposits on the sub-nm length scale.P revious coking studies on ZSM-5 in the MTH reaction have concentrated on the bulk, [7][8][9]13] or on micrometer length scales, [10,11,14,15] to gain some spatial insight, but none have been capable of delivering sub-nm resolution.Theo nly characterization method currently capable of spatially resolving 3D element distributions at the sub-nm scale is atom probe tomography (APT), which was first envisioned in the 1930s,b ut has recently experienced rapid growth due to improvements in instrumentation. [16][17][18][19][20] APT is able to create atom-by-atom 3D compositional reconstructions of materials within afabricated needle-...

Zeolites, having widespread applications in chemical industries, are often synthesized using organic templates. These can be cost‐prohibitive, motivating investigations into their role in promoting crystallization. Herein, the relationship between framework structure, chemical composition, synthesis conditions and the conformation of the occluded, economical template tetraethylammonium (TEA+) has been systematically examined by experimental and computational means. The results show two distinct regimes of occluded conformer tendencies: 1) In frameworks with a large stabilization energy difference, only a single conformer was found (BEA, LTA and MFI). 2) In the frameworks with small stabilization energy differences (AEI, AFI, CHA and MOR), less than the interconversion of TEA+ in solution, a heteroatom‐dependent (Al, B, Co, Mn, Ti, Zn) distribution of conformers was observed. These findings demonstrate that host–guest chemistry principles, including electrostatic interactions and coordination chemistry, are as important as ideal pore‐filling.

Establishing structure–reactivity relationships for specific channel orientations of zeolites is vital to developing new, superior materials for various applications, including oil and gas conversion processes. Herein, a well‐defined model system was developed to build structure–reactivity relationships for specific zeolite‐channel orientations during various catalytic reaction processes, for example, the methanol‐ and ethanol‐to‐hydrocarbons (MTH and ETH) process as well as oligomerization reactions. The entrapped and effluent hydrocarbons from single‐oriented zeolite ZSM‐5 channels during the MTH process were monitored by using operando UV/Vis diffuse reflectance spectroscopy (DRS) and on‐line mass spectrometry (MS), respectively. The results reveal that the straight channels favor the formation of internal coke, promoting the aromatic cycle. Furthermore, the sinusoidal channels produce aromatics, (e.g., toluene) that further grow into larger polyaromatics (e.g., graphitic coke) leading to deactivation of the zeolites. This underscores the importance of careful engineering of materials to suppress coke formation and tune product distribution by rational control of the location of zeolite acid sites and crystallographic orientations.