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We prepared Mo and Cr co-loaded ZSM-5 (Mo/Cr/ZSM-5) by a sequential impregnation method and applied it to methane dehydroaromatization (MDA) reaction.

We propose a visual detection method using a hyperswollen lamellar phase without electric amplification. Amphiphiles with an oligo(ethylene glycol) chain can catch alkali and alkaline earth metal ions and amplify to macroscopic birefringence.

Sasaki K., Hernandez Gaitan J.A., Tokuda Y., et al. A nanosheet molding method to estimate the size of bilayers suspended in liquids. Journal of Materials Chemistry C 10, 15816 (2022); https://doi.org/10.1039/D2TC03765C., Various methods have been developed to determine the size of molecular bilayer structures dispersed in liquids. We focused on the nanosheet (NS) growth inside the bilayers in hyperswollen lamellar (HL) phases. Here, we propose the method to evaluate the size of bilayers in liquid by observing palladium NSs (PdNSs) growing rapidly in the bilayers of the HL phase. It uncovered that the width of PdNSs depends on methanol concentration, on which the stability of the HL phase also depends. Considering that the stability of the HL phase is positively correlated with the width of bilayers, we concluded that the observation of PdNSs probably corresponds to the indirect measurement of the width of bilayers. This method will also be applied to various other bilayers. Moreover, the PdNSs of a few nanometers in thickness and several hundred nanometers in width show higher catalytic activity for the reduction reaction of 4-nitrophenol to 4-aminophenol than the previously reported Pd catalysts without any supports.

Koki Sasaki, Koji Miyake, Yoshiaki Uchida et al. Mechanochemical Synthesis of Dispersible Platinum Nanosheets for Enhanced Catalysis in a Microreactor. ACS Applied Nano Materials, 5 (4), 4998-5005, April 22, © 2022 American Chemical Society. https://doi.org/10.1021/acsanm.1c04583, Nanosheet fabrication usually requires some self-assembly process of the ingredients themselves or self-assembled templates to lead to the local anisotropy. Macroscopic forces and dynamics cannot usually generate the local anisotropy to synthesize nanosheets in a solution because the anisotropies of the macroscopic mechanical forces and dynamics are promptly relaxed in the molecular scale in a liquid phase. Here, we report the mechanochemical synthesis of dispersible platinum nanosheets (PtNSs) using a microreactor. This work is the first example of bottom-up nanosheet synthesis of a nonexfoliable compound in a microflow reactor. The nanosheets grow through the lateral fusion of nanoplatelets in the hydrophilic space of the stable hyperswollen lyotropic lamellar (HL) phase of a surfactant solution. The lateral fusion is accelerated as the flow rate increases because the area of the bilayer in the HL phase increases with shear stress. The mechanical energy to promote the growth of the PtNSs can also be extracted in different ways. Most simply, syringe pumps electrically generate it. We also illustrate mechanochemical synthesis using gravity, the most universal and eco-friendly energy source on the earth. It is also the first example of the fabrication of anisotropic nanoparticles using gravity. Larger PtNSs show higher catalytic activity for the reduction reaction from 4-nitrophenol to 4-aminophenol due to their dispersibility; surprisingly, the exponential increase of the fusion patterns of nanoplatelets dramatically reduces the agglomeration of PtNSs. These PtNSs perform better in catalysis and should be promising for hydrogen production, fuel cells, and sensors because of their large surface area and dispersibility. This method could open up a pathway to valuable nanosheets.

Uchida Y., Akita T., Hanada K., et al. Molecular clustering behaviour in the cybotactic nematic phase of a spin-labelled liquid crystal. Journal of Materials Chemistry C 10 , 6621 (2022); https://doi.org/10.1039/d2tc00626j., A newly synthesised liquid crystalline nitroxide radical (LC-NR) with a terminal trifluoromethyl group as spin-labelled LC compounds exhibits an anomalous phase transition behaviour. It is likely attributed to non-covalent interactions between the trifluoromethyl groups of the adjacent molecules. X-ray diffractometry of the LC-NR suggests the existence of a cybotactic nematic (Ncyb) phase with a transient and local layer order between the normal nematic (N) and smectic A (SmA) phases. The EPR spectroscopy of the spin-labelled LC implies no discontinuity in magnetic susceptibility around the N-to-Ncyb phase transition. Intermolecular contacts between nitroxide radicals seem to change continuously. These results imply that the interactions between trifluoromethyl groups induce the cybotactic clusters, where molecules move in and out.

Zr-doped SAPO-34 has enhanced Lewis acidity, leading to high catalytic activity for LDPE cracking.

Mg and Zn co-doped mesoporous ZSM-5 was prepared via impregnation of Mg and a Zn ion exchange using a commercial ZSM-5, which achieved a high yield of BTX and the improvement of catalyst lifetime on EDA reaction.

The synthesis strategy of highly dispersed Co/N-doped porous carbon materials using anion exchange resin and ionic liquids.

Vapor consisting of DMF and HCl promotes crystallization of in situ glycine-modified UiO-66.

This study evaluates the effect of loading various mono and divalent metals in Beta zeolite on low-density polyethylene (LDPE) cracking. We revealed that Tl and Ba ions enhanced Lewis acidity, leading to higher catalytic activity on LDPE cracking.

This study is one of the few to develop a strategy that inhibits coke deposition by loading Cr on zeolite defects. We revealed that Cr6+ species, which interacted with hydroxyl groups in the zeolite framework inhibited coke deposition.

N-doped carbon materials have attracted considerable attention as highly functional materials because nitrogen doping distorts the carbon lattice, changes charge density, and introduces additional defects. Among various positions of N...

This paper reports the random lasing and whispering gallery mode (WGM) lasing in dye-doped nematic liquid crystal (NLC) droplets. We discuss the emission behavior of the droplets in detail. Their lasing behavior depends on irradiation position and droplet diameter. Moreover, the two types of lasers likely share energy. Naturally, stopping one increases the efficiency of the other. Besides, the coexistence of the two types of lasers in an NLC droplet offers a controllable dye laser emitting two lights in different wavelength ranges.

Dry reforming of methane was studied over high-ratio zirconia in ceria-zirconia-mixed oxide-supported Ni catalysts. The catalyst was synthesized using co-precipitation and impregnation methods. The effects of the catalyst support and Ni composition on the physicochemical characteristics and performance of the catalysts were investigated. Characterization of the physicochemical properties was conducted using X-ray diffraction (XRD), N

Recently, NiSx based catalysts are promising electrocatalysts for Hydrogen Evolution Reaction (HER) via water electrolysis. In particular, the S/Ni ratio is crucial to improve catalytic activity of NiSx based catalysts. Herein, we synthesized NiSx based catalysts (Ni/S/C) with a tuned S/Ni molar ratio using Ni2+ ions exchange resin. We succeeded in synthesizing Ni/S/C with different S/Ni molar ratio in the range of 0.33–1.72 by changing Ni2+ ions exchange degree. The combination of NiSx and conductive carbon support contributes to high catalytic activity of Ni/S/C on HER. Additionally, Ni/S/C with the S/Ni molar ratio of 0.6 showed the highest onset potential; Ni3S2 is the most active catalyst for HER in NiSx species. Our synthesis method can easily tune the ratio of S/transition metal. This work provides a new direction for the catalyst design of transition metal sulfides and expands their utilization in sustainable catalytic reaction processes.

The energy shortage and environmental pollution crises have prompted the investigation of hydrogen based cleaner energy system. Therefore, hydrogen has been considered as a promising energy carrier due to its sustainability and environmentally friendly. This research considered the separation of hydrogen from mixed gas (H2 and N2) by using Pd-based membrane. In order to produce extra high purity of hydrogen, the separation of hydrogen using Pd-based membrane under steady state operation suffers from long time lag and membrane deactivation. These two technical problems leading to the decrease of hydrogen permeability were intensively addressed in this work. The separation of hydrogen was conducted by using a Pd/α-Al2O3 membrane with aim to improve the performance of separation, indicated by time lag and hydrogen recovery. The novel method of the dynamic membrane operation was applied by performing a composition modulation of the feed gas flow rate. The steady state operation was used as a base case for comparison to dynamic operation. All experiments were carried out at 325 °C, atmospheric pressure, and H2/N2 ratio of 1:1, while varying the switching time and concentration amplitude for dynamic operation. The Pd based membrane was prepared, characterized, and it showed no pin hole could be found. The permeability constants for unsteady state condition resulted in higher when compared to steady state condition. The experiment results showed that the recovery of hydrogen under steady state condition was 21%. On the other hands, the recovery of hydrogen under invoked unsteady state operation was significantly improved three times higher than that of the steady state operation. The recovery of hydrogen increased 8–13% when the feed gas amplitude decreased from 1.5 mL/s to 0.5 mL/s. Operations at 300 s switching time and 0.5 mL/s flowrate amplitude reached the hydrogen recovery up to 63%.

Sasaki Koki, Gaitan Jose A. Hernandez, Okue Tsuyoshi, et al. Amorphous Aluminosilicate Nanosheets as Universal Precursors for the Synthesis of Diverse Zeolite Nanosheets for Polymer‐Cracking Reactions. Angewandte Chemie 134, (2022); https://doi.org/10.1002/ange.202213773., Zeolites catalyze some reactions in their molecular-sized pores, but large molecules can react only on their external surface. Zeolite-nanosheets (NSs) have been developed as catalysts for large molecules. The previously reported methods to synthesize zeolite-NSs are specialized for each zeolite type. Here we propose a new method to synthesize various zeolite-NSs from the same amorphous aluminosilicate NSs (AAS-NSs) as a universal precursor. We successfully synthesized the unprecedented AAS-NSs in the hydrophilic space of the stable hyperswollen lyotropic lamellar (HL) phase. The four zeolite types could be obtained from the single-species AAS-NSs. These results imply that this method enables us to synthesize almost all types of zeolite-NSs. Moreover, the synthesized CHA-NSs have great potential for various applications because of their thickness and large external surface area.

A simple, rapid and sensitive vinyl-functionalized mesoporous carbon-based dispersive micro-solid phase extraction method has been developed for the preconcentration and quantification of azole ant...

We have synthesized very thin nanosheets (NSs) of metal-organic frameworks (MOFs) in sandwich-like reaction fields (SRFs) inside the bilayers of a hyperswollen lyotropic lamellar (HL) phase. The ob...

Chabazite SSZ-13 has attracted wide attention due to its physiochemical properties and excellent potential as a catalyst for various application. In this study, pure phase SSZ-13 CHA zeolite with wide range of Si/Al ratio has been synthesized in a fluoride-free media by dry gel conversion method where the conversion of SSZ-13 from aluminosilicates precursor gel occurs under water vapor. The difference between products produced by conventional hydrothermal synthesis method and the new method has been investigated and characterized with XRD, SEM, XRF, and N2 adsorption. Pure SSZ-13 with wide range of Si/Al up to 182 was obtained by dry gel conversion method while pure SSZ-13 with higher Si/Al ratio than 20 with similar starting gel composition could not synthesized by hydrothermal synthesis method. Our work has demonstrated that dry gel conversion method was an effective method to synthesize pure SSZ-13 with a wide range of Si/Al ratio under fluoride media-free condition.