Search

Nanostructured materials have attracted attention due to their unique chemical and physical properties different from the bulk. Some nanostructures transform their shape through reactions like oxidation and reduction. Here, we report the Cu2O nanourchin synthesis using spontaneous growth from Cu nanosheets (CuNSs). The CuNSs are synthesised inside the bilayers of the hyperswollen lamellar phase. The obtained CuNSs become Cu2O after drying at 90°C. Atomic force microscopy indicates that the CuNSs are oxidised in the air in the heating process to give Cu2O nanourchins. [ABSTRACT FROM AUTHOR]

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. The Mo/Cr/ZSM-5 showed better catalytic performance on MDA reaction than only Mo-loaded ZSM-5. [ABSTRACT FROM AUTHOR]

Recently, NiS x 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 NiS x based catalysts. Herein, we synthesized NiS x 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 NiS x 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; Ni 3 S 2 is the most active catalyst for HER in NiS x 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. Image 1 • NiS x doped carbons (Ni/S/C) are synthesized using Ni2+ ion exchanged resin. • S/Ni molar ratio of Ni/S/C can be tuned by ion exchange degree. • Ni/S/C with S/Ni ratio of 0.60 showed the highest catalytic activity on HER. • Ni 3 S 2 is the most active species for HER in NiS x. [ABSTRACT FROM AUTHOR]

We describe herein the preparation of ZSM-5/hydrotalcite composites and their catalytic activity for the formation of 5-hydroxymethylfurfural (5-HMF) from glucose. The composites with high surface area and sufficiency in both acidity and basicity were achieved by the hydrothermal and dry gel methods, denoted as ZSM-5/HT-hydr and ZSM-5/HT-dg, respectively. Used as a combined solid acid–base catalyst in a biphasic H2O/THF/NaCl system, the ZSM-5/HT composites showed excellent bifunctional catalytic activities since the base sites on HT promoted an isomerization of glucose to fructose, while the acid sites on ZSM-5 enhanced a successive dehydration of fructose to 5-HMF. Under the optimized reaction conditions, this catalytic process provided over 90% glucose conversion with ＞65% yield of 5-HMF at 150 °C for 120 min and 0.1 : 1 mass ratio of catalyst to glucose. Even through both ZSM-5/HT composites exhibited a comparable catalytic performance, ZSM-5/HT-hydr was more stable, selective, reusable, and preferable for one-pot synthesis of 5-HMF from glucose in the studied conditions. [ABSTRACT FROM AUTHOR]

Abstract 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 N 2 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. Graphical abstract Image 1 Highlights • We performed dry gel conversion synthesis for SSZ-13 under fluoride-free and seed-free condition. • Pure SSZ-13 with high silica (up to Si/Al = 182) was obtained by dry gel conversion under fluoride-free and seed-free condition. • The comparative investigation revealed that dry gel conversion method was an effective method to synthesize pure SSZ-13 with a wide range of Si/Al ratio under fluoride-free and seed-free condition. [ABSTRACT FROM AUTHOR]

Abstract An efficient and simple methodology was proposed to synthesize CHA zeolite without the use of solvent and OSDA. The synthesis strategy is based on a mechanochemical-assisted interzeolite transformation using only Na-type FAU zeolite and KOH as starting materials, for ease of handling and large-scale production. The role of KOH on crystal transformation behaviors and adsorption characteristics of the obtained CHA zeolite were investigated. The important factor was the loading KOH into the cages of starting FAU zeolite with adjusted appropriate amount. In this method, vapor-solid interzeolite transformation occurs by local rearrangement of silicon and aluminum species without accompanying macroscopic dissolution of FAU zeolite, resulting in formation of CHA zeolite maintaining the Si/Al ratio of the starting FAU zeolite. Graphical abstract Image 1 Highlights • Highly versatile methodology to transform FAU zeolite into CHA zeolite without the use of solvent and OSDA. • CHA zeolite with the same Si/Al ratio as starting FAU zeolite could be achieved. • Mechanochemical-assisted interzeolite transformation using only Na-FAU and KOH for easy-to-use and large-scale production. [ABSTRACT FROM AUTHOR]

Abstract Development of electrocatalysts for oxygen reduction reaction (ORR) is important to solve the current problems about energy and fuel. As one of the catalysts with high performance, platina group metals (PGM) based catalysts have been widely known. However, PGM based catalysts are not suitable for large commercial application since the PGM based catalysts are so expensive. In this work, we have developed TiO 2 P25 coated with Co and nitrogen-doped carbon layers using commercially available and inexpensive P25 as a support (Co/P25/NC) as one of the alternatives to PGM based catalysts. Co/P25/NC showed an excellent catalytic activity on ORR compared to the other catalysts prepared using SiO 2 , ZrO 2 and Al 2 O 3 as a support. The ORR activity of Co/P25/NC was comparable to Pt based electrocatalysts. In addition, Co/P25/NC showed excellent durability and tolerance toward methanol compared to the Pt based catalyst. This work would provide a new synthetic strategy of electrocatalysts. [ABSTRACT FROM AUTHOR]

Abstract Zeolite Beta has been widely utilized on large molecular systems because of its three dimensional large micropores, 12-membered ring. Controlling amount of acid and its strength of zeolites depending on the composition is very crucial to improve their catalytic performance. Incorporation of heteroatoms into the framework of zeolites is one of the effective ways to control catalytic activities. However, it is difficult to synthesize high-silica zeolite Beta with heteroatoms, which has been limiting the functions of zeolite Beta. To overcome the problem, we developed a dry gel conversion method using dealuminated zeolites; we can synthesize *BEA type ferrisilicate (Fe-Beta). In this method, it is necessary to use two silica sources; dealminated Beta and colloidal silica. The dissolving process of these silica sources by NaOH plays a significant role in the crystallization to Fe-Beta. The Fe-Beta shows higher selectivity to isobutene on acetone-to-olefins (ATO) reaction compared to Al-Beta and Fe-MFI. This is due to the acid strength weakened by substituting Al by Fe and the large diffusivity of isobutene in the large micropores of *BEA structure. Graphical abstract Image 1 Highlights • High silica Fe-Beta was synthesized by dry gel conversion (DGC) method using dealuminated Beta. • Fe-Beta showed weaker acid strength than Al-Beta. • Fe-Beta showed higher selectivity to isobutene on acetone-to-olefins (ATO) reaction. [ABSTRACT FROM AUTHOR]

In this work, a dual-functional catalyst with (1) catalytic activity of metal catalysts and (2) shape-selectivity of zeolites has been developed. We have fabricated Pt nanoparticles encapsulated in core-shell single crystal like silicalite-1 zeolite (CS-Pt/s-1) by a crystalline overgrowth method. The CS-Pt/s-1 catalyst showed much higher catalytic hydrogenation activity of n -hexene compared to cyclohexene. [ABSTRACT FROM AUTHOR]

Mechanical properties of ultra‐thin organic films are fundamentally important in coating applications. Micromechanical cantilever sensor (MCS) and laser‐based surface acoustic wave (LA‐SAW) techniques were both used to measure Young's moduli (E) of plasma polymerized films at different humidities (H). For plasma polymerized allylamine (ppAA) films deposited at 5 W and 90 W, E of 1400 ± 350 MPa and 110 ± 20 MPa at H between 10 and 40%, and 1070 ± 250 MPa and 32 ± 10 MPa at H between 70 and 80% were measured. The LA‐SAW technique revealed E lower than 60% of that measured by MCS. The difference suggested either an enhanced swelling at the air interface or a gradient of cross‐linking density. [ABSTRACT FROM AUTHOR]

We have synthesized MFI type ferrisilicate zeolite (Fe-MFI) nanocrystals with a crystal size smaller than 100 nm by a dry gel conversion (DGC) method using a sole template (tetrapropylammonium hydroxide). The crystal size of Fe-MFI synthesized by the DGC method was much smaller than that of Fe-MFI synthesized by a conventional hydrothermal synthesis (HTS) method despite using the same precursor solution. The catalytic performance of the nano-sized Fe-MFI in methanol to olefin (MTO) reactions was investigated. The Fe-MFI catalysts showed higher propylene to ethylene (P/E) ratios and lower light paraffin yields compared with MFI type aluminosilicate zeolites (Al-MFI) for both the synthesis methods. In addition, nano-sized Fe-MFI showed a higher P/E ratio (ca. 30) and a longer catalyst lifetime than macro-sized Fe-MFI synthesized by the HTS method. [ABSTRACT FROM AUTHOR]

Abstract Zeolites have been conventionally synthesized using organic structure directing agents (OSDA) in solvent. In this work, we synthesized various zeolites from unseeded aluminosilicate via mechanochemical and vapor treatments in the absence of OSDA and solvent. Various types of zeolites were successfully synthesized from starting materials with different Si/Al ratios. With an increase of Si/Al from 1 to 20, different phases appeared in the order of CAN, ANA, MOR, MFI and α-quartz. This work provides a new insight of zeolite synthesis. Graphical abstract Image 1 Highlights • Zeolites were synthesized from unseeded aluminosilicate without OSDA and solvent. • Mechanochemical and vapor treatments were used in this process. • Zeolites with different frameworks were successfully synthesized in our method. [ABSTRACT FROM AUTHOR]

We successfully designed Zn ion doped ZSM-5/silicalite-1 core-shell zeolite catalyst. On methanol to para -xylene (MT p X) over the core-shell catalyst, p -xylene yield was 40.7 C-mol% and para -selectivity ( para -xylene selectivity in xylene isomers) was higher than 99 C-mol%, which substantially exceeds the other results reported in the literature. [ABSTRACT FROM AUTHOR]

Abstract: Various synthesis methods of zeolites have been established. Hydrothermal synthesis method with organic structure directing agent (OSDA) has been widely applied in zeolite synthesis. However, this method has some big problems in terms of industrial and environmental aspects: OSDA is expensive and thermally decomposed OSDA produces air pollution; and the yield of zeolite crystals per reactor volume is low due to the presence of solvent. We hence synthesized ZSM‐5 (MFI‐type zeolite) in the absence of both solvent and OSDA to overcome these problems. Briefly, the starting materials including silica powder, sodium aluminate, sodium hydroxide and a small amount of seed crystals (ZSM‐5) were mixed together and grinded using a ball mill. Then the milled powder was crystallized under a steam atmosphere by varying crystallization time. We found that an MFI phase started to appear after 12 h and the formation of pure ZSM‐5 crystals was completed after 24 h. Our method provides a simpler and efficient process of zeolite synthesis in an environment‐friendly manner than those of any conventional solvent methods, which will promise to promote mass production of a variety of zeolites. [ABSTRACT FROM AUTHOR]

The molecular motion of surface-immobilized double-decker phthalocyanine complexes was examined using STM. (C8OPc)2Ce (1), (C12OPc)2Ce (2), and (C8OPc)Ce(Pc) (3) double-decker complexes, of which two ligands contained Pc nuclei, formed well-ordered self-organized structures on their own. Square- shaped top Pc ligands were clearly observed for complexes 1, 2, and 3 even though free space presented around the top ligands caused by mixing the complexes with template molecules. However, the details of the shapes of the top ligands of complexes 1, 2, and 3 were changed by the surrounding environment. The surrounding environment was considered to have influenced the mobility of the top ligands. Another complex, (C8OPc)Ce(TPP) (4), had difficulty forming a self-organized structure by itself. Complex 4 could have been immobilized by coadsorbing on the substrate with the C8OPc template, but the intramolecular structure of the top ligands of complex 4 was difficult to obserVe. The results strongly suggested that combinations of molecules composed of double-decker complexes as well as the free space presented around a top ligand are important factors that control the molecular motion of immobilized double-decker complexes on solid surfaces. [ABSTRACT FROM AUTHOR]

[Display omitted] • Zn ion doped MFI type galloaluminosilicate zeolite (Zn/[Ga,Al]-MFI) was synthesized. • Zn/[Ga,Al]-MFI was the ideal catalyst for stable ethane dehydroaromatization. • The acidity tuned by a partial substitution of Ga for Al suppressed a coke formation. Ethane dehydroaromatization (EDA) reaction is one of the promising processes to meet the growing demand of aromatics in the future. Zn ion exchanged MFI type aluminosilicate zeolite (Zn/[Al]-MFI) shows high activity on EDA reaction. Zn ion and Brønsted acid derived from Al sites contribute to the high activity on EDA reaction, but excess strong acid sites promote coke formation, leading to rapid deactivation. Herein, we have developed a new synthesis method for Zn ion exchanged MFI type galloaluminosilicate zeolite (Zn/[Ga,Al]-MFI). The coke formation was suppressed by partially substituting Al with Ga since acidity derived from Ga sites are weaker than that derived from Al sites. Zn/[Ga,Al]-MFI was the ideal catalyst to achieve both high catalytic activity and stability on EDA reaction. Our work provides a new design direction of zeolite catalysts on EDA reaction, which can contribute to the progress on the transformation of light alkanes to value-added chemicals. [ABSTRACT FROM AUTHOR]

By means of scanning tunneling microscopy (STM), we succeeded for the first time in the quantitative analysis of the intramolecular conformation of a supramolecule, cyclodextrin (CyD) necklace, driven by hydrogen bonding. Contrary to the current model, based on macroscopic analyses, which indicates that all CyDs are arranged in head-to-head or tail-to-tail (secondary-secondary or primary-primary hydrogen bonding) conformation, about 20% head-to-tail (primary-secondary hydrogen bonding) conformation was found to exist in the molecule. In addition, comparing the STM results with the theoretical model of the necklace formation, the formation ratio of the tail-to-tail and head-to-tail conformations due to the strength difference between primary-primary and primary-secondary hydrogen bonds of CyDs was directly obtained, for the first time, to be 2:1. [ABSTRACT FROM AUTHOR]

We developed a thermal flying-height control (TFC) slider to control the flying height of magnetic recording heads. The slider basically consists of a small heater fabricated near the read/write element. This study discusses the effect of heater size and heater location on the change in the flying height at the read/write element. We also discuss the resulting temperature rise due to the additional heat applied by the heater. Specifically, we have found that small heaters generally resulted in lower heater power per unit change in the flying height and lower head temperature rise per unit change in the flying height. In terms of heater location, we have found that a heater closer to the air-bearing surface (ABS) also tends to result in a larger change in the flying height because of the larger protrusion shape. However, the head temperature rose significantly. Therefore, shorter ABS/heater distance was a trade off lower power against higher rise in head temperature. We concluded that smaller heaters and the shorter ABS/heater distance are better as long as head reliability is ensured. [ABSTRACT FROM AUTHOR]

Selective catalytic reduction (SCR) of NO x with zeolite catalysts has been reported as the most promising technique for the removal of NO x from diesel engine exhaust. In this research, SSZ-13 zeolite doped with Cu species was synthesized by dry gel conversion (DGC) method and applied as a catalyst for NH 3 -SCR. The obtained Cu/SSZ-13 was characterized using X-ray diffraction (XRD), Energy-Dispersive X-ray (EDX), Scanning Electron Microscopy (SEM), NMR spectroscopy, ESR spectroscopy, nitrogen adsorption. Cu/SSZ-13 synthesized by DGC method has higher crystallinity and porosity than that synthesized by conventional hydrothermal synthesis (HTS) method. Due to its higher crystallinity and porosity, higher amount of Cu ions was introduced into SSZ-13 synthesized by DGC method, leading to a higher catalytic performance for the SCR of NO x compared with Cu/SSZ-13 prepared by HTS. In addition, Cu/SSZ-13 synthesized by DGC method showed higher hydrothermal stability. Image 1 • SSZ-13 with higher crystalline and microporosity was synthesized by dry gel conversion (DGC) method. • Higher amount of Cu2+ could be introduced into SSZ-13 prepared by DGC method compared to SSZ-13 prepared by conventional hydrothermal synthesis method. • Cu/SSZ-13 prepared by DGC method showed better catalytic performance on NH 3 -SCR due to its higher crystalline and microporosity. [ABSTRACT FROM AUTHOR]

To evaluate the lubrication compatibility of SiC-reinforced Ti3SiC2-based composites, i.e., a Ti3SiC2/SiC composite, with water and alcohol, sliding experiments were conducted under dry condition and lubricated with water and C2H5OH. The friction and wear of the Ti3SiC2/SiC composite decreased in the order of dry condition, in water, and in C2H5OH. The worn surfaces indicated that oxide masses, which caused oxidation wear and abrasive wear, were formed by tribo-oxidation on the sliding surface under the dry condition and in water, while tribo-oxidation scarcely occurred in C2H5OH. [ABSTRACT FROM AUTHOR]

Using atomic force microscopy with a spherical indenter, we evaluated the surface and bulk elastic modulus of thick and thin polystyrene films. The elastic modulus of the thick films at penetration depths of more than 10 nm was equivalent to that of bulk measured by a tensile test. In the thin films, the estimated values were greatly affected by the substrate material at penetration depths of more than 7 nm. When the penetration depth was less than 5 nm, however, the elastic modulus of both thin and thick films was slightly smaller than that of the bulk values. [ABSTRACT FROM AUTHOR]

Protrusion of the recording element during the write process due to Joule heating and eddy-current losses adds a significant constraint in reducing the flying height of sliders found in magnetic recording devices. Variation of the drive temperature also adds similar constraint to the system. One method of overcoming these challenges is to control the relative position of the magnetic recording transducer with respect to the disk surface by thermally heating the transducer region, a concept outlined in a U.S. patent. In this paper, we experimentally show that the thermal actuation concept outlined in the patent can indeed be employed to control the magnetic spacing. [ABSTRACT FROM AUTHOR]

In the long history of zeolite research, further enhancement of their acid strength has looked difficult. In this study, we achieved the enhancement by incorporating Ge into the zeolite framework. We synthesised the zeolites by a dry gel conversion method and characterised them in terms of morphology, crystal structure, and composition. We determined the acid strength of these zeolites by calculating the change in the enthalpy of desorption in the temperature‐programmed desorption of ammonia and confirmed that the acid strength of the zeolites with Ge was higher than that of a conventional zeolite. This enhancement of acid strength probably originated from the unprecedented interactions between Al and Ge, unlike the conventional interactions between Al and Si. The enhanced acid strength led to high efficiency of ethanol‐to‐propylene reactions, affording higher yield of propylene than that obtained using conventional zeolites. [ABSTRACT FROM AUTHOR]

Adsorbed molecular films, referred to as boundary films in tribology, are widely used in various industrial products as a keyway for surface functionalisation, such as lubricity, wettability, and adhesion. Because boundary films are thin nanometre-scale molecular layers and can easily be removed, their formation process cannot be elucidated in detail. In this study, to analyse the growth dynamics of boundary films, the film thickness and molecular orientation of the boundary film of a fatty acid used as an additive in rolling contact as mechanical stimuli were measured in situ. The measurements were performed on simple test lubricants, which were composed of n-hexadecane and stearic acid, at rolling tribological condition between steel and glass (or sapphire) surfaces by ultrathin film interferometry combined with sum-frequency generation spectroscopy according to a unique protocol. The results quantitatively demonstrate shear-induced boundary film formation. The insight gained from these results is anticipated to enable the formulation of high-performance lubricant additives to further reduce friction loss and high-performance glues that can be freely designed for removability. [ABSTRACT FROM AUTHOR]

Today's oxygen reduction reaction (ORR) depends on the precious metal Pt‐based catalysts, limiting the large commercialization of promising energy conversion technologies such as proton exchange membrane fuel cells (PEMFCs) and metal‐air batteries. Therefore, the rational design of low‐cost and highly efficient electrocatalysts for ORR is strongly desired. Herein, we report a porous carbon doped with nitrogen, fluorine, and phosphorus (N, F, P tri‐doped carbon) prepared via only a heating process using low‐cost glycine, ammonium fluoride, and phytic acid as precursors. X‐ray photoelectron spectroscopy (XPS) analysis revealed the existence of pyridinic‐N and the co‐existence of graphitic‐N and oxidized graphitic‐P, which can be active sites, with semi‐ionic C−F bonds highly boosting ORR activity. Remarkably, the resultant N, F, P tri‐doped carbon exhibited outstanding activity for the ORR with an onset potential comparable to that of commercial 20 wt % Pt/C catalyst, the half‐wave potential superior to that of the Pt/C catalyst, and the electron transfer number close to 4. [ABSTRACT FROM AUTHOR]

CHA-type silicoaluminophosphate zeolite (SAPO-34) has been utilized as a functional material in various applications such as reactions and separations due to its unique pore structure and acidity. Various efforts have been made to improve its performance. However, the Lewis acidity of SAPO-34 has not been focused on so far. Herein, Zr-doped SAPO-34 was synthesized by a dry gel conversion using amorphous ZrO2–SiO2 with highly-dispersed Zr species to control the Lewis acidity of SAPO-34. The Zr-doped SAPO-34 had only highly-dispersed Zr species, which interacted with the frameworks of SAPO-34, while bulky ZrO2 was formed in Zr-loaded SAPO-34 prepared by an impregnation method. The Zr-doped SAPO-34 showed higher catalytic activity in low-density polyethylene cracking than a pristine SAPO-34 and Zr-loaded SAPO-34. The higher catalytic activity is likely to originate from the highly-dispersed Zr species showing Lewis acidity without inactive bulky ZrO2. This work can provide a new direction for the design of SAPO-34. [ABSTRACT FROM AUTHOR]

For wide use and cost reduction of proton exchange membrane fuel cells (PEMFCs), the development of transition-metal-doped porous carbon (TMPC) electrocatalysts for the oxygen reduction reaction (ORR) is urgently needed. Herein, we report a new strategy for designing CoNx-doped carbon materials with fine-tuned porosity via anion exchange and CO2 activation processes. Highly dispersed CoNx species are introduced into carbon materials by the anion exchange process. After that, the porosity of the CoNx-doped carbon is controlled by an optimized CO2 activation. The precisely controlled active sites and porosity of the obtained catalyst (Co/N/C-act) lead to an extraordinary ORR performance in an alkaline medium. This work paves a new direction in development strategy not only for electrocatalysts but also for other potential applications, such as water splitting and supercapacitors. [ABSTRACT FROM AUTHOR]

A microwave plasma (MP) cathode for ion sources has advantages of a long lifetime for reactive gas, and a capability of a high-current electron emission of several amperes. This article describes a new MP cathode, in which a convergent magnetic field is formed at an electron emitting aperture in order to improve the working gas efficiency, that is the decreasing of the gas flow rate (Q[sub eff]) to obtain the electron emission current of 1 A. By applying a magnetic field (∼3 kG), the Q[sub eff] was decreased to 1/5 to 1/10 of that in the conventional MP cathode, and a high current of oxygen ion beam of 62 mA in a high vacuum (1.8×10[sup -5] Torr) system was successfully obtained. Further improvements are expected by changing various parameters. [ABSTRACT FROM AUTHOR]

Investigates the electronic structure of silicon(111)-7x7 phase boundary. Utilization of scanning tunneling microscopy in the analysis; Relation of the observed charge transfer to the structural change in the dimer layer; Agreement of the results with the similar chemical reactivity observed in the two disordered structures.

Zeolites have been applied in various chemical processes due to their multi-functionality. In practical use of zeolites, their hydrothermal stability is one of the important factors. We focused on the coating with hydrophobic silicalite-1, which is all silica MFI zeolite. In this work, we investigated the hydrothermal stability of ZSM-5 (MFI type aluminosilicate zeolite) coated with silicalite-1 (all silica MFI zeolite) by the combination of steam treatment and NH 3 temperature programed desorption (NH 3 -TPD). The peak area at higher temperature (h-peak area) in NH 3 -TPD profiles for core-shell MFI zeolite (ZSM-5/s-1) was unchanged even after steam treatment for 8 h in contrast to uncoated ZSM-5. These results strongly indicate that extremely high Si/Al ratio on the external surface coated with silicalite-1 is highly effective for improving the hydrothermal stability; the hydrophobicity of silicalite-1 probably prevents the penetration of steam into Al sites of ZSM-5. This work opens up a new function of the silicalite-1 layer on ZSM-5 other than improvement of shape selectivity. Image 1 • The hydrothermal stability of acid sites in Core-Shell ZSM-5/silicalite-1 was investigated. • The hydrothermal stability of acid sites improved by coating silicalite-1 layer. • The increase of Si/Al ratio on the external surface mainly contributes to improving hydrothermal stability of acid sites. [ABSTRACT FROM AUTHOR]

Zeolite deactivation induced by coke deposition is a critical problem in the industrialization of the chemical recycling (CR) of plastics. We previously demonstrated that Cr6+ species bonded to silanol groups in the zeolite framework inhibit coke deposition in low‐density polyethylene (LDPE) cracking. In this study, the role of Cr6+ species and the mechanism of coke reduction were determined experimentally. During LDPE cracking, hydrogen was generated from the alkane products at the Cr6+ sites. Furthermore, the hydrogenation and decomposition of aromatics, which are coke precursors, occurred at the zeolitic acid sites, resulting in the reduction of coke deposition. Owing to the synergistic effect of the Cr6+ and zeolitic acid sites, coke reduction was achieved without reducing cracking activity. [ABSTRACT FROM AUTHOR]

The manufacture of efficient and low‐cost hydrogen evolution reaction (HER) catalysts is regarded as a critical solution to achieve carbon neutrality. Herein, we developed an economical method to synthesize a CoP‐anchored N‐doped carbon catalyst via one‐step pyrolysis using inexpensive starting materials (cobalt ion salt, phytic acid, and glycine). The size of the CoP nanoparticles was controlled by adjusting the Co/P ratio of the catalysts. Nanoscale CoP particles with adequate exposure to active sites were uniformly anchored on the surface of the conductive nitrogen‐doped carbon substrate, ensuring the rapid transfer of electrons and species. When Co/P=0.89, the as‐made catalyst exhibited outstanding HER activity, with an extraordinarily low overpotential of 202 mV at 10 mA cm−2 and long‐term stability. [ABSTRACT FROM AUTHOR]

A great decrease in the crystallization time of EU-1 zeolite to 10 h was achieved by coupling between the microwave-assisted hydrothermal synthesis and the addition of fluoride as crystallization promoter in the presence of 10% EU-1 seeds in alkaline media. Interesting characterization results were obtained by observing an octahedral coordination of Al incorporated with the fluoride presented in the synthesis in the form of AlO 4 F 2 . This finding was confirmed by analyzing the spectra of FTIR and 27 Al MAS NMR which showed additional peak attributed to AlO 4 F 2 . The short crystallization time offered a significant decrease of EU-1 particle size to ∼500 nm as observed on FE-SEM. A pure phase of EU-1 was synthesized in the range of 25–100 Si/Al ratio. An intergrowth phase of EU-1 and ZSM-48 was observed on XRD when 200 Si/Al ratio gel was prepared. Excellent catalytic performance of DME conversion to olefins was achieved over the co-crystalline EU-1 and ZSM-48 sample. The sample showed exceptional stability for 360 min on stream compared with other samples and the highest olefins selectivity which reached to 78%. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor about several cases of successful use of interferon for male infertility.

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

• S-doped Co 2 P loaded on P and S co-doped carbon was syntheiszed using ion exchange resin with a sulfonic acid group. • The optimized catalyst showed high hydrogen evolution reaction (HER) activity with 161 mV of overpotential at 10 mA/cm2. • S species was introduced into the Co 2 P lattice, which should lead to the achieving the suitable hydrogen adsorption-free energy. Co 2 P is a promising catalyst for the hydrogen evolution reaction (HER) because of its excellent conductivity. Herein, we developed a facile method to synthesize a S-doped Co 2 P anchored P,S co-doped carbon catalyst via an ion-exchange process and one-step pyrolysis. Through prolonged ion exchange, cobalt ions were uniformly immobilized onto the organic carbon framework, ensuring a uniform distribution of Co 2 P nanoparticles and robust interactions between the resultant product and carbon substrate. The agglomeration of the Co 2 P nanoparticles during pyrolysis was prevented, thus generating a larger number of exposed active sites. In addition, doping with S can efficiently regulate the electronic states of the Co sites, resulting in an improved ΔG H*. The best catalyst exhibited outstanding HER activity, with an extraordinarily low overpotential of 161 mV to achieve a current density of 10 mA cm−2 in 0.5 M H 2 SO 4. Compared with the mechanically stirred sample and the sample without S atoms, the catalytic activities of the samples subjected to ion exchange are improved by 37.8 % and 54.2 % respectively. [ABSTRACT FROM AUTHOR]

Hydrogen is widely considered an emissions-free alternative energy carrier for sustainable energy devices, such as fuel cells and nickel-metal hydride batteries. Recently, electrochemical hydrogen evolution reaction (HER) from water splitting has been attracted as an eco-friendly process for producing hydrogen. Herein, we report a Co/P-doped carbon material (Co/P/C) derived from cobalt-aluminum layered double hydroxide nanosheets (LDHs) for HER. The Co/P/C was synthesized using triethyl phosphite as phosphate and carbon sources by a one-step chemical vapor deposition (CVD) process. The regular arrangement of Co and Al atoms in the precursor LDHs allowed Co/P species to be highly dispersed under optimized CVD conditions. The carbon nanotube formed by the CVD process improved the catalytic activity of Co/P/C. The optimized Co/P/C exhibits a low overpotential of 240 mV at −10 mA cm−2 for HER, comparable to the commercial Pt/C catalyst. This work provides a new direction for developing transition-metal and hetero-atom co-doped carbon materials with high catalytic activity for HER. • Co/P-doped carbon materials are prepared by using layered double hydroxide. • The metal aggregation was prevented by the unique of the layered double hydroxide. • The deposition process using triethyl phosphite can introduce desire Co/P species. • The synthesized Co/P/C shows excellent activity for HER in an acidic media. [ABSTRACT FROM AUTHOR]

Abstract: This paper reported a novel innovation of electrical contact structure in flexible device technology. A coating of poly(3,4-ethylenedioxythiophene) poly(4-styrenesulfonate) (PEDOT:PSS) as a solid electrolytic layer deposited on silicone elastomer structure is employed in composing the electrical circuit through a large area of woven electronic textile (e-textile), and functions as the electrical contact between weft and warp (interlaced) fiber ribbons. It was observed that the elastomer structure itself had no major damage after 106 cycles load test with a force of 1N (≈100MPa). The resistance of PEDOT:PSS coated elastomer structure in contacted with the plain PEDOT:PSS coated polyethylene terephthalate (PET) ribbon with a force of 10mN was measured at about 300Ω. These results show a promising durability and electrical transfer ability within the limitations of materials employed for reel-to-reel continuous processes. From the bending experiments using flexible sheet by weaving PET ribbon cables, the structure enhances the flexibility and stability of electrical contact in the woven e-textile better than those of the ribbons without it. [Copyright &y& Elsevier]

Purpose: To analyze the horizontal rectus extraocular muscles (EOMs) by orbital magnetic resonance imaging (MRI) in patients with congenital cranial dysinnervation disorders that arises from abnormal development of cranial nerve nuclei or their axonal connections. Design: Case series, retrospective analysis. Methods: The morphology of the horizontal rectus EOMs was analyzed in orbital MRI on 4 patients with congenital oculomotor palsy, 26 with congenital superior oblique palsy, and five with Duane syndrome. Orbital imaging was performed by 1.5 tesla (T) and 3T MRI, and quasi-coronal and sagittal images perpendicular and parallel to the long axis of the orbit were obtained at slice thicknesses of 3 and 2 mm. Results: The horizontal rectus EOMs were split in 4 of the 35 patients (11%). Splitting was observed in 2 of the five patients (40%) with Duane syndrome, one of the 26 patients (4%) with congenital superior oblique palsy, and 1 of the 4 patients (25%) with oculomotor palsy, but in none of the 6 normal subjects and 12 patients with acquired cranial nerve palsy. Conclusion: Since splitting of the horizontal rectus EOMs was noted in patients with congenital dysinnervation disorders, including Duane syndrome, Sevel''s theory that the horizontal rectus EOMs develop from the superior and inferior mesodermal complexes is considered to be reasonable. [Copyright &y& Elsevier]

Two kinds of SiC-reinforced titanium-matrix composites were slid against themselves in water and in ethanol to evaluate the influence of their microstructure on the wear behavior. The composites had a structure in which the SiC particles were coated with interfacial layers that consisted of Ti5Si3C x and TiC, and the TiC particles were dispersed in a titanium matrix. The wear resistance of the composites was much better than that of titanium metal. The wear of the composites prepared from starting materials with a high SiC content was lower than that with a low SiC content. [ABSTRACT FROM AUTHOR]

UiO-66, composed of a Zr6O4(OH)4 cluster and 1,4-benzene dicarboxylate, is a promising material for practical chemical processes because it is known as one of the most thermally and chemically stable Metal Organic Frameworks (MOFs). Recently, the structure and composition of UiO-66 have been modified in various ways to improve its functionality and expand its utilization. Herein, we report the synthesis of in situ glycine-modified UiO-66 using a vapor-assisted crystallization (VAC) method. The VAC method using HCl turned out to be the most suitable for synthesizing of glycine-modified UiO-66 with high crystallinity and porosity. Modifying glycine enhanced the CO2 adsorption capacity. In XPS measurement on Zr 3d, the peak shift to higher binding energy was observed by modifying glycine. This result implys that carboxylates derived from glycine chemically interacted with defects of Zr clusters. This work provides a new direction to modify UiO-66. [ABSTRACT FROM AUTHOR]

The flexible DLC film is one of the novel techniques to deposit the DLC film on polymer materials such as rubber and resin, which does not cause any peeling-off of the film even with the deformation of the substrates. It was found that the DLC film deposited by modulated RF plasma-CVD has the features of (1) small friction, (2) small wear (less than Teflon), (3) high water repellency (90° contact angle for pure water), (4) good insulation characteristic (surface resistance on the order of 1012 Ω cm), (5) less peeling-off due to expansion and contraction of the polymer material, and (6) deposition at lower temperatures (below 80°). This new DLC film is applied to the rubber seal ring (O-ring) for zoom lens system of 35 mm compact cameras. The flexible DLC technique is expected to expand itself and to create wider applications of DLC films. [Copyright &y& Elsevier]

Proton-exchange-membrane fuel cells (PEMFCs) are of considerable interest as a sustainable, renewable, efficient, and eco-friendly electrochemical conversion systems of energy. Sluggish oxygen reduction reaction (ORR) as the cathodic reaction have mainly dragged down the PEMFCs in practical use. The most effective catalyst for ORR today is a Pt-based catalyst, which have a high scarcity value and low durability for methanol. Therefore, major efforts have recently been devoted to exploring transition metal and hetero-atom doped carbon materials in fuel cells for large-scale and commercial applications. Herein, we report a facile synthesis route of Co-N doped meso/microporous carbon catalysts (Co/N/MPC-act) via self-assembly of resorcinol-based resin, triblock co-polymer and Co containing ionic liquid followed by CO 2 activation. The obtained catalyst exhibited outstanding oxygen reduction activity in an alkaline medium. It yields an onset potential of 0.960 V (vs. RHE) and a limiting current density of 5.0 mA/cm2, which are comparable to that of the commercial Pt/C catalyst. This high activity is contributed by the combination of inter-connected meso/microporous structures and highly dispersed CoN x species with metallic Co. The Co/N/MPC-act catalyst exhibited excellent long-term operation stability and methanol tolerance, making it a promising non-precious metal-based ORR catalyst for PEMFCs. [Display omitted] • Co/N doped meso-micro porous carbon (Co/N/MPC-act) was prepared by self-assembly process and CO 2 activation. • Co/N/MPC-act contains high content of pyridinic-N and Co-N. • Co/N/MPC-act exhibits an impressive high catalytic performance for ORR. • Co/N/MPC-act shows better durability and tolerance to methanol for ORR than 20 wt% Pt/C. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cephalopod-inspired extremely rapid self-repairing coatings are designed that can repair surface. • The introduction of counter-ions into polyelectrolyte multilayers produces the mimicking coatings. • Mimicking the cephalopod's self-healing mechanisms achieved ultrafast self-repair within 10 sec. • The key technology has various potential applications and contributes to the development of a sustainable society. Emerging materials capable of self-repair to damaged areas are attracting attention for environmental protection and energy reduction. Although coatings whose material elasticity physically restores surface-dents are in practical use, in the case of crack damage, they cannot perform their self-repairing function. Conversely, coatings that exhibit the capacity to repeatedly repair themselves chemically have been challenged by long repair times. Here water-induced, self-repairing coatings inspired by cephalopod self-healing mechanisms were developed that can ultra-rapidly repair surface scratches. The introduction of counter-ions into polyelectrolyte multilayers produced coatings mimicking the strong β -sheet structures, noncovalent intermolecular interactions, and consequently self-repair process in cephalopods. These features resulted in a decrease in the strong polycation–polyanion electrostatic bonds and an increase in the noncovalent polymer networks. Furthermore, counter-ion addition improved the coating's water absorption and retention properties. The ion-trapped polymer networks facilitated expansion in the horizontal direction where a scar was present, resulting in ultrafast self-repairing rate of 92% in 1 s and 100% in 10 s. These extremely rapidly self-repairing coatings have various potential applications given knowledge acceleration via machine learning. The key technology developed here paves the way for novel insights into the construction of self-repairing materials and contributes to the development of a sustainable society. [ABSTRACT FROM AUTHOR]

The preparation method of nanosheets using hyperswollen lyotropic lamellar phases, the 'two-dimensional reactor in amphiphilic phases (TRAP) method', has successfully provided nanosheets of various non-layered materials. Previously reported examples started from a single hydrophobic or hydrophilic precursor and multiple hydrophobic precursors. Here, we propose a synthesis method of nanosheets of ZIF-8, zinc 2-methylimidazolate, with a sodalite-like framework. They grow up to a few nanometers of thickness and several hundred nanometers of width with neither aggregation nor impurities from multiple hydrophilic precursors in the stoichiometric ratio inside the hydrophilic TRAPs consisting of the amphiphile Brij L4. The thin nanosheets of ZIF-8 doped with Co2+ (Co-ZIF-8) synthesized by the same method maintained a high specific surface area after calcination. Therefore, the oxygen reduction reaction (ORR) activity of the calcined Co-ZIF-8 NSs for fuel cells becomes higher than that of the calcined conventional Co-ZIF-8 crystals. [ABSTRACT FROM AUTHOR]

• This study describes the synthesis of N and F co-doped carbons by zeolite templating method using fluoropyridine. • N, F co-doped carbons showed better ORR activities than N doped carbon prepared using pyridine. • The optimized N, F co-doped carbon showed a quite high half-wave potential of 0.87 V vs. RHE. • Precise introduction of semi-ionic F species boosted the ORR activity. Heteroatom-doped carbons have attracted increasing attention in recent years as inexpensive high-performance electrocatalytic materials owing to their electrical properties. A precisely controlled synthesis method for heteroatom-doped carbons is important to improve their performance and expand their applications. In this study, we developed a fluoropyridine-medicated zeolite templating method for Nitrogen/Fluorine (N/F) co-doped carbons. The N/F co-doped carbons showed better catalytic performances for oxygen reduction reaction (ORR) than N-doped carbon prepared using pyridine. In particular, the optimized N/F co-doped carbon exhibited a higher half-wave potential (0.87 V vs. RHE) than commercial Pt-loaded carbon black and N/F co-doped carbons reported in the literature. The comparative studies using various N/F co-doped carbons revealed that semi-ionic bonded C-F might improve ORR activity. In contrast, the contribution from covalent or ionic C-F to improving ORR activity would be negligible. [ABSTRACT FROM AUTHOR]

Electrocatalysts used in sustainable energy conversion devices, such as fuel cells and air-metal batteries, have been widely investigated. Pt-based catalysts are widely used in the oxygen reduction reaction (ORR), which is a key reaction in these devices; however, these catalysts are highly expensive and unstable, thus impeding commercialization. Therefore, metal-free catalysts have attracted significant research interest as alternatives to noble-metal-based catalysts. We synthesized N and P co-doped carbon using a mixture of glycine and phytic acid, followed by CO 2 activation to improve porosity. The optimized catalyst (CNP-act825-4) exhibited onset and half-wave potentials of 0.925 V vs. reversible hydrogen electrode (RHE) and 0.838 V vs. RHE, respectively. Density functional theory calculations revealed that the catalytic performance was attributed to the synergistic effects between graphitic-N and oxidized graphitic-P, in addition to the suitable porosity for ORR. This study provides a simple method for synthesizing N and P co-doped carbon and describes the effects of introducing N and P in electron distribution for ORR activity. This study demonstrates that N and P co-doping facilitates the effective preparation of highly active metal-free N and P co-doped catalysts. This study unlocks the possibility of maximizing the potential of metal-free multi-heteroatom-doped carbons for electrocatalytic processes via precise nanoscale control of the chemical states of multi-heteroatoms and pore structures. [Display omitted] [ABSTRACT FROM AUTHOR]