Start with the transition state Zeolites catalyze a wide range of industrial reactions, but identifying reactions that they well tends to be done by trial and error. Gallego et al. propose way rationalize process using structure-directing agents act as scaffolds for creating zeolite pores channels (see Perspective Millini). They picked molecules mimic states such isomerization ethylbenzene into xylene, successfully identified catalysts improved reactant conversion product selectivity....

Selectivity control in zeolite synthesis Zeolites are widely used many industrial applications, but despite decades of research, their still relies on trial-and-error approaches. Complex nucleation mechanisms and topological diversity lead to strong phase competition, complicating the issue rational design synthesis. Using atomistic simulations, literature mining, human-computer interaction, synthesis, characterization, Schwalbe-Koda et al . developed a computational strategy that enables...

Organic structure directing agents (OSDAs) play a crucial role in the synthesis of micro- and mesoporous materials especially case zeolites. Despite wide use OSDAs, their interaction with zeolite frameworks is poorly understood, researchers relying on heuristics or computationally expensive techniques to predict whether an organic molecule can act as OSDA for certain zeolite. In this paper, we undertake data-driven approach unearth generalized OSDA–zeolite relationships using comprehensive...

Novel sunscreens are required providing active protection in the UVA and UVB regions. On other hand, there is an increasing concern about photosafety of UV filters, as some them not sufficiently photostable. Avobenzone one most frequently employed sunscreen ingredients, but it has been reported to partially decompose after irradiation. In present work, photophysical photochemical studies on a methylated avobenzone-derivative have shown that diketo form responsible for photodegradation. A...

An efficient synthesis methodology to obtain homogeneous nanosized high-silica Beta zeolites (∼10-20 nm) with high solid yields (above 95%) using simple alkyl-substituted flexible dicationic OSDAs is described. These allow the of different Si/Al ratios (15-30) in alkaline and fluoride media, resulting nanocrystalline materials physico-chemical properties. show better catalytic behavior towards industrially-relevant alkylation benzene propylene cumene compared other commercially available zeolites.

The catalysts used in the methanol-to-olefins (MTO) reaction are considered dual systems comprising an inorganic zeolite framework and organic compounds hosted inside that act as cocatalysts. influence of cavity architecture on preferential stabilization cationic intermediates involved paring side-chain routes hydrocarbon pool mechanism is analyzed by means density functional theory (DFT) calculations, catalyst testing, 13C NMR spectroscopy for some small-pore cage-based zeolites. A...

From theoretical calculations and a rational synthesis methodology, it has been possible to prepare nanocrystalline (60-80 nm) chabazite with an optimized framework Al distribution that positive impact on its catalytic properties. This is exemplified for the methanol-to-olefin (MTO) process. The nanosized material predicted maximizes formation of required MTO hydrocarbon pool intermediates, while better precluding excessive diffusion pathways favor rapid catalyst deactivation by coke formation.

A novel ab initio methodology based on high-throughput simulations has permitted designing unique biselective organic structure-directing agents (OSDAs) that allow the efficient synthesis of CHA/AEI zeolite intergrowth materials with controlled phase compositions. Distinctive local crystallographic ordering intergrowths was revealed at nanoscale level using integrated differential contrast scanning transmission electron microscopy (iDPC STEM). These have been tested for selective catalytic...

Metal-containing zeolites, especially Sn-Beta, perform as very efficient heterogeneous catalysts in the selective oxidation of levoglucosenone, which is considered a platform chemical for production highly-valuable chemicals, towards synthesis optically pure γ-lactone (S)-γ-hydroxymethyl-α,β-butenolide (HBO) using H2O2 an oxidizing agent. Using Sn-Beta catalyst, yields up to 75% are achieved "one-pot" cascade reaction. When combined with acid resin, such Amberlyst-15, "two-step" process allows 90%.

Light alkenes oligomerization, performed in the presence of heterogeneous acid catalysts, is an interesting alternative for production clean liquid fuels. The process, when catalyzed by zeolites, flexible and can be directed to formation oligomers gasoline, jet fuel, or diesel range adjusting reaction conditions zeolite's structure. Herein we show how reducing crystal size large-pore Beta zeolites down 10–15 nm controlling number strength distribution their Brønsted sites leads highly active...

By combining kinetics and theoretical calculations, we show here the benefits of going beyond concept static localized defined active sites on solid catalysts, into a system that globally dynamically considers site located in an environment involves scaffold structure particularly suited for target reaction. We demonstrate such is able to direct reaction through preferred mechanism when two them are competing. This illustrated industrially relevant reaction, diethylbenzene–benzene...

Zeolites are industrial catalysts and adsorbents whose synthesis usually employs specific molecules known as organic structure-directing agents (OSDAs). The OSDA’s templating effect is pivotal in determining the zeolite polymorph formed its physicochemical properties. However, de novo design of selective OSDAs challenging because diversity size zeolite-OSDA chemical space. Here, a computational workflow powered by machine learning enables an exhaustive exploration OSDA space for zeolites....

The synthesis of the ZSM-5 and beta zeolites in their nanosized form has been achieved by using simple alkyl-substituted mono-cationic cyclic ammonium cations as OSDA molecules. particular combination a fragment short linear alkyl-chain group (preferentially C4) within monocationic molecules allows directing crystallization with excellent solid yields (above 90%). Interestingly, formation mostly depends on size nature molecule, resulting all cases nanocrystalline solids homogeneous...

The selective incorporation of isolated framework Lewis acid sites in specific crystallographic positions high-silica zeolites was achieved successfully by applying a rationalized post-synthetic grafting methodology.

DS-ITQ-2 has been proposed as catalyst for the Diels–Alder (DA) reaction between 2,5-dimethylfuran and ethylene to produce<italic>p</italic>-xylene based on fact that organic molecule employed its synthesis mimics DA intermediate cycloadduct.

Abstract The light olefin product distribution of the methanol‐to‐olefin (MTO) reaction catalyzed by acid zeolites and zeotypes depends on nature entrapped hydrocarbon pool species that act as co‐catalysts. preferential stabilization confinement effects cationic intermediates involved in side‐chain or paring pathways aromatics‐based cycle MTO mechanism small‐pore cage‐based is determined topology cavity, can be quantitatively described through E int(7/5) parameter obtained from DFT...

The design of diverse Ni-zeolites has been performed attempting to control different physico-chemical properties the zeolite supports as well Ni speciation study their influence on industrially relevant ethylene oligomerization reaction. In this sense, Ni-containing medium-pore MFI and large-pore BEA zeolites have synthesized with particle sizes, Si/Al molar ratios following Ni-incorporation strategies (one-pot versus post-synthesis). Characterization techniques reveal preferential presence...

By using a Diels-Alder (DA) reaction as base case, we show that pure silica zeolite acting an entropy-trapping scaffold can be synthesized with organic structure directing agent (OSDA) analogue of the transition state (TS) DA reaction. A cavity stabilization TS is observed corresponding decrease in activation energy lower enthalpy and larger entropy are obtained when compared other zeolitic structures. Those differences maintained, while catalytic activity increased, active sites introduced...

Non surfactant cyclic alkylammonium can selectively decrease the rate of crystal growth along <italic>x</italic>–<italic>y</italic> axes during synthesis MWW zeolite.

Cyclobutane pyrimidine dimers (CPD) and (6-4) photoproducts are among the main UV-induced DNA lesions. Both types of damage mostly repaired in prokaryotes by photolyase enzymes. The repair mechanism photolyases has still not been fully elucidated, but it is assumed that back rearrangement to oxetane occurs prior repair. In this work, a non-steroidal anti-inflammatory drug derivative corresponding dechlorinated methyl ester carprofen (namely 2-(carbazol-2-yl)propanoate, PPMe) used achieve...

Zeolites are industrial catalysts and adsorbents whose synthesis usually employs specific molecules known as organic structure-directing agents (OSDAs). The OSDA’s templating effect is pivotal in determining the zeolite polymorph formed its physicochemical properties. However, de novo design of selective OSDAs challenging because diversity size zeolite-OSDA chemical space. Here, a computational workflow powered by machine learning enables an exhaustive exploration OSDA space for zeolites....

Al-rich MTW zeolites show large pore accessibility, high Brönsted acidity and activity for the cracking of <italic>n</italic>-decane.