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Pyrolysis oil (bio-oil) consists of high water content and vast variety of oxygenates (acids, alcohols, aldehydes, esters, ketones, sugars and phenols), causing some undesirable properties that prevent the direct use of bio-oil as a transportation fuel. Bio-oil upgrading to decrease its oxygen content provides a sustainable fuel that can be considered a valuable substitution for depleting fossil fuels. Catalytic hydrodeoxygenation (HDO) is an efficient method for bio-oil upgrading. This paper presents the HDO of crude bio-oil in supercritical fluid (ethanol, methanol, and 2-propanol) using a batch high pressure reactor. Supercritical fluids have unique physicochemical properties of liquid-like density and gas-like high diffusivity and low viscosity. The upgrading efficiency was evaluated by measuring the elemental composition (CHNS O), water content, carbon residue, and high heating value (HHV) of the bio-oil upgraded over Ni/HBeta catalyst. Compared to ethanol and 2-propanol, supercritical methanol resulted in a higher decrease in the oxygen content of bio-oil. The activity of Ni/HBeta was examined by varying the Ni loading (5–20 wt%), initial hydrogen pressure (10–30 bar), and reaction time (2–6 h). Meanwhile, effects of support materials (HZSM-5, HBeta, HY, Al-SBA-15, and silylated HBeta) on the performance of nickel catalyst in bio-oil upgrading were investigated using supercritical methanol. Image 1 • Enhanced deoxygenation (46.37 wt%) of bio-oil over Ni/HBeta in supercritical MeOH. • Improved HHV of bio-oil from 12.61 to 26.04 MJ/kg (up to 2 times increase). • 36.83 wt% decrease in the carbon residue of bio-oil using supercritical HDO process. [ABSTRACT FROM AUTHOR]

Previous suicide attempts are a leading risk factor for completed suicide. To identify specific characteristics of those at high risk for attempts, we investigated associations with socioeconomic status (SES). Data from the 2013 Korean Community Health Survey (KCHS) included adults who reported suicidal ideation (N = 220,245). Attempts in the past 12 months were assessed. Associations of demographic, socioeconomic, and suicide-related behavioral factors were analyzed using multiple logistic regression. Among those with suicidal ideation, 862 (3.9%) had attempted suicide. After stratification by age and gender, results showed that low education and unemployed young adult men and women had significantly higher rates of attempts. The lowest income level was associated with significantly higher rates of attempts in only young adult women. Among those with the lowest and highest income, the association between ideation and attempts was attenuated, whereas it was enhanced among other income groups. [ABSTRACT FROM AUTHOR]

Abstract: Methyl-modified silica materials with dual mesopore size distribution have been successfully obtained by co-condensation of methyltriethoxysilane and tetraethylorthosilicate via sol-gel method. Non-ionic surfactant, alkyl polyethylene oxide CH3(CH2)12(EO)9, is used as the structure-directing agent, which can be easily removed by solvent extraction. The materials thus obtained exhibit two kinds of mesopores: framework mesopore and textural mesopore with mean pore sizes of about 2.2 and 12nm, respectively. The presence of methyl groups in the framework is proved by FT-IR, TGA and 29Si MAS NMR measurements. The effect of the methyl groups on adsorption properties for water and benzene has also been investigated in the present work. [Copyright &y& Elsevier]

Adsorption and conversion of various hydrocarbons on monolithic hydrocarbon adsorbers were studied using a new experimental model, temperature-programmed adsorption (TPA). In this study, methyl alcohol, acetone, acetaldehyde, 2,2,4-trimethylpentane, n-octane, and toluene were chosen as model hydrocarbons for cold start of a vehicle. The effect of the hydrocarbon components and oxygen concentration on the TPA curve was investigated. Depending on the presence of O2, the adsorbed and desorbed amounts of the hydrocarbons were decreased, while the conversion efficiency of the hydrocarbons was increased. In the case of hydrocarbons containing oxygen, the thermal decomposition appeared to be in the order methanol, acetaldehyde, and acetone. [Copyright &y& Elsevier]

The objective of this study was to report electrocatalytic activity of tin selenide (SnSe) for oxygen evolution process (OER) and hydrogen evolution reaction (HER). Simple and inexpensive SnSe thin films were deposited onto a steel substrate using an electrodeposition method. Orthorhombic SnSe required a low overpotential value of 325, 317, 314 mV for OER and a low overpotential value of 273, 219, 194 mV for HER for SnSe-1, SnSe-2, and SnSe-3 electrodes, respectively, to reach a current density of 10 mA/cm2. The thickness of thin film increased over time 50, 60, and 70 min for each successive SnSe-1 to SnSe-3 samples. SEM image indicated crystalline in nature with compact grain-like morphology on the entire surface of the substrate. The SnSe-3 sample displayed low Tafel slopes of 90 and 68 mV/dec for OER and HER, respectively. EDX showed that atomic percentage ratio of Sn: Se was 54:46 for SnSe-3 thin film. Overall results suggest that electrochemically synthesized SnSe is a promising candidate as an efficient electrocatalyst for overall water splitting. [Display omitted] • Electrodeposited SnSe thin films were successfully synthesized. • The influence of deposition time on catalytic performance was examined. • Electrocatalytic analysis of SnSe was performed to capabilities of OER and HER. • The catalytic activity exhibited stability over a period of 12 h. [ABSTRACT FROM AUTHOR]

This study describes the single-step synthesis of a mesoporous layered nickel-chromium-sulfide (NCS) and its hybridization with single-layered graphene oxide (GO) using a facile, inexpensive chemical method. The conductive GO plays a critical role in improving the physicochemical and electrochemical properties of hybridized NCS/reduced GO (NCSG) materials. The optimized mesoporous nanohybrid NCSG is obtained when hybridized with 20% GO, and this material exhibits a very high specific surface area of 685.84 m2/g compared to 149.37 m2/g for bare NCS, and the pore diameters are 15.81 and 13.85 nm, respectively. The three-fold superior specific capacity of this optimal NCSG (1932 C/g) is demonstrated over NCS (676 C/g) at a current density of 2 A/g. A fabricated hybrid supercapacitor (HSC) reveals a maximum specific capacity of 224 C/g at a 5 A/g current density. The HSC reached an outstanding energy density of 105 Wh/kg with a maximum power density of 11,250 W/kg. A 4% decrement was observed during the cyclic stability study of the HSC over 5000 successive charge–discharge cycles at a 10 A/g current density. These results suggest that the prepared nanohybrid NCSG is an excellent cathode material for gaining a high energy density in an HSC. [ABSTRACT FROM AUTHOR]

With the rapid growth of secondary batteries used in various industries, methods for analyzing battery elements such as electrodes and electrolytes have also improved. In addition, as the utility of nano‐scaled electrode materials have attracted greater attention, it has become increasingly clear that conventional electrochemical analytic methods have limitations. Consequently, electron microscopy and even synchrotron x‐ray radiation techniques have been adopted and are now widely used. Among several advanced analytical techniques, synchrotron radiation‐based operando small‐angle x‐ray scattering (SAXS) enables real‐time analysis of changes in the ordering of nanostructures and in the electron densities of electrodes and solid electrolytes during electrochemical reactions. In this review, the principle and applications of operando SAXS are briefly introduced, to help in understanding the complex nanostructural behaviors of battery components used in secondary batteries, and furthermore, it is hoped to contribute to innovative materials design. [ABSTRACT FROM AUTHOR]

Scheelite-type surfactant-assisted SrWO4 was prepared via a simple co-precipitation method. The effect of various surfactants such as hexamethylenetetramine, polyvinylpyrrolidone, and sodium dodecyl sulphate, on the structural, morphological and photoluminescence (PL) properties of SrWO4 was investigated. Powder X-ray diffraction and the Rietveld profile refinement technique confirmed the tetragonal structure of all the as-synthesized SrWO4 materials. Among the three surfactants, particles with spherical morphology were observed for SDS-assisted SrWO4. Surfactant-assisted SrWO4 exhibited bluish-green emission around 500 nm, ascribed to the presence of WO 4 2 - luminescence centre at 284 nm excitation, and the PL emission intensity significantly increased in the presence of surfactant. Electron density distribution analysis of a single unit cell for all the prepared materials was investigated, and correlated with the PL results. [ABSTRACT FROM AUTHOR]

In this study, the ordered mesoporous metal oxides (TiO 2 and SnO 2 ) and compound semiconductors (ZnS, ZnSe, CdS, and CdSe) are manufactured and they exhibit several micrometers (μm) of particle size, and high surface area of about 100 m 2 g −1 . Well-developed crystallinities are prepared via simple nano-replication method by using a 3-D bicontinuous cubic Ia 3 d meso-structured ordered mesoporous silica KIT-6 as a hard-template. The visible-light-driven photocatalytic CO 2 conversion into CH 4 is carried out in the presence of H 2 O over various mesoporous materials. Prepared mesoporous materials show different light absorption behaviors and photocatalytic activities for conversion of CO 2 . The mesoporous compound semiconductors show higher CO yield rates than the mesoporous metal oxides, while mesoporous metal oxides show higher CH 4 yield rates than the mesoporous compound semiconductors. Compared to the commercial TiO 2 material (P25, Degussa), the mesoporous metal oxides (TiO 2 , SnO 2 ) show 9 to 10 times higher yields of CH 4 and 2 to 3 times higher yields of CO owing to their high surface area. Especially, the mesoporous ZnS shows the highest CH 4 yield rate (3.620 μmol g cat −1 h −1 ) and the mesoporous CdSe shows the highest CO yield rate (5.884 μmol g cat −1 h −1 ) out of all photocatalysts considered in the present study. Although mesoporous CdS and ZnSe have great visible light absorption properties, they show relatively low CH 4 yield rates. [ABSTRACT FROM AUTHOR]

Ordered mesoporous MCo 2 O 4 (M = Cu, Zn and Ni) spinel catalysts were synthesized via nano-replication method using mesoporous silica KIT-6 as the hard template. They were applied to methane combustion, in comparison with bulk MCo 2 O 4 spinel catalysts prepared by co-precipitation method. A combined N 2 adsorption-desorption, XRD and TEM results clearly confirm that mesoporous MCo 2 O 4 (m-MCo 2 O 4 ) spinel catalysts contain ordered mesostructure, resulting in the higher BET surface area and pore volume than bulk ones (b-MCo 2 O 4 ). Moreover, the former catalysts demonstrate the better thermal stability as indicated by larger amount of MCo 2 O 4 phase and smaller size of crystallite domain after calcination at 550 °C. Therefore, such excellent properties rationalize that the m-MCo 2 O 4 spinel catalysts reveal higher catalytic activity for methane combustion than bulk counterparts. When it comes to the catalytic performance of the meso catalysts for methane combustion, the m-CuCo 2 O 4 spinel catalyst has superior performance, which is related to the high normalized amount of Co 3+ cations on the surface, as evidenced by XPS. [ABSTRACT FROM AUTHOR]

Particle board and polypropylene (PP) at a mixing ratio of 1:1 were copyrolyzed over two Al-MCM-48 catalysts with Si/Al ratios of 20 and 80. The catalyst characteristics were examined by measuring the Brunauer-Emmett-Teller surface area, temperature programmed desorption of ammonia, and X-ray diffraction. The main pyrolysis products of particle board were oxygenates, acids, and phenolics, whereas a large quantity of hydrocarbons within the diesel fuel range was produced from copyrolysis with polypropylene. The catalytic copyrolysis of particle board and PP over the Al-MCM-48 catalysts produced bio-oil with a much larger hydrocarbon content than that from the catalytic pyrolysis of particle board only. The hydrocarbons produced were mainly in the diesel range, highlighting the potential for the production of high-quality fuel. [ABSTRACT FROM AUTHOR]

H-V-MCM-41 catalysts containing 5, 10, and 30 wt% of vanadium were synthesized and applied to the ex situ catalytic pyrolysis (CP) of three polymeric components of lignocellulosic biomass for the first time. Characterization of the catalysts was performed using N 2 adsorption–desorption, XRD, FT-IR, and NH 3 -TPD. The results of XRD analysis showed that 5 wt% and 10 wt% H-V-MCM-41 catalysts maintained the mesoporous structure, whereas the mesoporous structure was destroyed in 30 wt% H-V-MCM-41 with considerable amount of small V 2 O 5 crystalline outside the framework. NH 3 -TPD showed that H-V-MCM-41 has mostly weak acid sites and that 10 wt% H-V-MCM-41 had the largest quantity of acid sites due to framework vanadium. In the case of CP of cellulose using Py-GC/MS, 10 wt% H-V-MCM-41 showed the highest catalytic activity for the production of valuable furanic compounds such as furfural because of the enhanced deoxygenation over the acid sites formed on framework vanadium. In the case of CP of xylan as well, 10 wt% H-V-MCM-41 led to the largest yield of mono-aromatics. The production of acetic acid was also promoted by H-V-MCM-41 catalysts. The CP of lignin over H-V-MCM-41 catalysts promoted substantially the production of important feedstock chemicals for the petrochemical industry: phenolics and mono-aromatics. [ABSTRACT FROM AUTHOR]

Mesoporous, nanocrystalline alkali promoted Pd/TiO 2 (K–PT) catalyst was prepared by an evaporation induced self-assembly method using P123 as the pore generator. Series of catalysts were prepared by increasing the Pd molar ratio from 0.1 to 1.0. All of the prepared catalysts were characterized thoroughly by using different physico-chemical methods, such as X-ray diffraction, Raman, transmission electron microscopy, X-ray photoelectron spectroscopy, etc. Water gas shift (WGS) reaction was carried out in order to evaluate the catalytic activity of the prepared materials. Among all, the highest CO conversion has been observed with 0.8Pd/TiO 2 . Introduction of K increases the CO conversion mainly at low temperature range between 200 °C and 350 °C. Interestingly, all the prepared catalysts show nearly 0% methane formation. In order to understand the relationship between structure and catalytic activity, the spent catalysts were also analyzed by all physico-chemical methods. Incorporation of K along with Pd reduces the extent of sintering, which in turn increases the stability of the catalyst during the course of WGS reaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • The novel material Mo 2 RuP with I̅ 42m structure was synthesized. • The DOS and COHP calculations were used to study the electronic structure of Mo 2 RuP. • DFT showed that Ru-incorporation effectively reduced Δ G H* on multiple crystal planes. • Intensified alkaline HER performance of Mo 2 RuP at high current density was confirmed. • The HER stability of Mo 2 RuP was elucidated by using COHP. In accordance with the Sabatier principle, Mo-based catalysts typically exhibit lower catalytic activity in the hydrogen evolution reaction (HER) due to strong interactions between Mo and hydrogen within their structures. To overcome this limitation, here, we introduce a novel approach by incorporating Ru into Mo 3 P to modify its electronic structure, resulting in a novel water splitting cathode material of I̅ 42m structured Mo 2 RuP. Notably, Mo 2 RuP demonstrates as an efficient catalyst for alkaline HER, exhibiting outstanding performance with extremely low overpotentials of 29 mV and 62 mV at current densities of 10 mA cm−2 and 100 mA cm−2, respectively. It also displays a small Tafel slope (30 mV dec-1) and long-term durability in hydrogen production even at a current density of 100 mA cm−2 in a 1 mol/L KOH solution. First-principles density functional theory (DFT) calculations elucidate that Ru-substitution significantly reduces the hydrogen adsorption Gibbs free energy on various crystal facets of Mo 2 RuP. This alteration facilitates the transformation of the material to the kinetically favorable Volmer-Heyrovsky pathway during the HER. Furthermore, a comprehensive characterization and investigation into the electronic structure of this innovative material validate the efficacy of Ru modulation within the Mo 3 P structure. The strategy of Ru-substitution to adjust the electronic structure of Mo-based catalysts offers a viable approach for the development of novel, stable, and high-performance catalysts for the HER. [ABSTRACT FROM AUTHOR]

Nitrogen-doped (N-doped) graphene films with up to a 17.39 at.% doping level were synthesized with the chemical vapor deposition growth method. An extensive range of tunable nitrogen doping levels was achieved by selecting organic molecules as precursors grown at a wide temperature range of 300 to 1000 °C. The benzene rings in the precursor significantly reduced the energy requirements of N-doped graphene. The incorporation of bridgehead nitrogen and amino groups ensured a high nitrogen doping level and offered the tunable modulation of nitrogen dopant concentrations. The influence of temperature on the nitrogen content was investigated, distinguishing the graphitic and pyridinic dopant types, each demonstrating unique trends considering the dopant stability and growth mechanism. Specifically, the proportion of graphitic doping could be modulated from 40 % to 100 %. Notably, the pyrrolic type was absent at lower temperatures and was nearly negligible at elevated temperatures. Therefore, we developed a synthesis method for N-doped graphene growth that allowed for the selective and prioritized tuning of nitrogen dopant types. This method is particularly favorable when specific nitrogen dopants at certain doping levels are required for electrical and chemical catalytic applications. [Display omitted] • Tunable nitrogen doping content up to 17.39 at.% concentration was achieved at a wide temperature range of 300 to 1000 °C. • Prioritization of dopant types, including tunable graphitic and pyridinic dopants with nearly negligible pyrrolic content. • Graphitic dopant ratio ranged from 40% to 100%. [ABSTRACT FROM AUTHOR]

The movement of the sulfur species of a lithium – sulfur battery cathode was directly observed through pioneering operando SAXS analysis. Micropore is a prior repository for sulfur before and after the electrochemical reaction. Mesopore is actual reaction site for sulfur species. The separate properties of the pores were established, adding critical insight to advanced carbon cathode material design. [ABSTRACT FROM AUTHOR]

Abstract: Catalytic oxidation of benzene with ozone has been studied using manganese oxides with two different manganese precursors, Mn(NO3)2 and Mn(CH3COO)2, supported on SBA-15 (MnO x /SBA-15). The catalysts were characterized by X-ray diffraction, N2 adsorption–desorption, Raman spectroscopy, and H2-temperature programmed reduction. The manganese nitrate (MN) precursor primarily resulted in large particles on the silica support, while the manganese acetate (MA) precursor mainly resulted in a highly dispersed manganese oxide on the silica support. The catalytic activity was dependent upon ozone concentration, reaction times, and the amount of Mn loading. Higher benzene conversion, O3 conversion, and CO x yield were observed for MnO x -MA/SBA-15 catalyst over MnO x -MN/SBA-15, due to the highly dispersed manganese oxides on the supports, and the higher oxygen mobility. The 15wt% MnO x -MA/SBA-15 catalyst shows the highest catalytic activity of all the catalysts considered in this study. [Copyright &y& Elsevier]

Abstract: Highly ordered mesoporous α-Mn2O3 was synthesized from cubic mesoporous silica (KIT-6) via nano-casting method. The mesoporous α-Mn2O3 thus obtained was calcined at 200–500°C, and characterized using XRD, N2 sorption and temperature-programmed reduction (TPR). The calcination temperature did not significantly affect the BET surface areas, mesopore sizes, pore structures and crystallinities of the mesoporous α-Mn2O3 materials. The mesoporous α-Mn2O3 calcined at 300°C showed the highest catalytic activity due to its high reduction ability revealed from the TPR analysis. However, the catalytic activity was negligible without ozone. In addition, the selectivity to CO2 was about 90% and this seems to be an advantage of mesoporous α-Mn2O3 for removing benzene using ozone. [Copyright &y& Elsevier]

Mesoporous silica, SBA-15 was successfully functionalized with quinoline moiety, and was applied as a matrix in the MALDI-TOF-MS analysis of small molecules. The modified SBA-15 material [SBA-15-8-(3-(triethoxysilyl)propoxy) quinoline, SBA-15-8QSi] was obtained by using calcined SBA-15 and 8-hydroxy quinoline. The structure of the functionalized mesoporous material was systemically characterized by TEM, the N2 adsorption-desorption isotherm technique and FT-IR spectra. Compared with DHB and SBA-15, SBA-15-8QSi demonstrated several advantages in the analysis of small molecules with MALDI-TOF-MS, such as less background interference ions, high homogeneity, and better reproducibility. Based on these results, the various analytical parameters were optimized. The ideal operating conditions were (1) methanol used as the dissolving solvent; (2) sample first dropping method; (3) a ratio between the analyte and the matrix of 3.5:10. Under these optimization conditions, a low detection limit (8 pmol for L-Arginine-HCl) and high reproducibility (≤29%) were obtained. This technique was successfully applied to the analysis of various types of small molecules, such as saccharides, amino acids, metabolites, and natural honey. [Copyright &y& Elsevier]

Abstract: Manganese oxide catalysts prepared by a precipitation method with various precipitants were investigated for the low temperature selective catalytic reduction (SCR) of NOx with NH3 in the presence of excess O2. Various characterization methods such as N2 adsorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA) and X-ray absorption near edge structure (XANES) were conducted to probe the physical and chemical properties of MnOx catalysts. The active MnOx catalysts, precipitated with sodium carbonate and calcined in air at moderate temperatures such as 523K and 623K, have the high surface area, the abundant Mn4+ species, and the high concentration of surface oxygen on the surface. The amorphous Mn3O4 and Mn2O3 were mainly present in this active catalyst. The carbonate species appeared to help adsorb NH3 on the catalyst surface, which resulted in the high catalytic activity at low temperatures. [Copyright &y& Elsevier]

Abstract: Cu–Mn mixed oxides were prepared by a co-precipitation method and applied for low temperature NO reduction with NH3 in the presence of excess oxygen. Effects of [Cu]/[Mn] ratio and calcination temperatures on NOx conversions were investigated. Cu–Mn oxide catalysts containing small amounts of copper showed the complete NOx conversion in a wide range of reaction temperature from 323 to 473K. This catalyst showed a reversible deactivation due to the presence of water vapor and SO2. Different catalytic activities of Cu–Mn mixed oxides could be attributed mainly to surface areas and the crystalline nature. [Copyright &y& Elsevier]

Nanometer-sized (below 100°nm) bimodal mesoporous aluminosilicate molecular sieves (NBMAS) are obtained by using sol–gel method and cetyltrimethylammonium bromide (CTAB) as the structure-directing agent. Ordering-packed framework mesopore is created within the colloidal particles by the templating function of surfactant CTAB and disordered textual pore is formed by the aggregation of colloidal particles as an inter-particle pore. As a result of the special properties of the present material, the hydrothermal stability and catalytic life of the material is highly improved in the catalytic cracking reactions. ZSM-5, normal AlMCM-41 and amorphous alumina–silica with nanometer particle size were used in the catalytic cracking process for comparing purpose. [Copyright &y& Elsevier]

Emissions from diesel engines, including hydrocarbons (HCs), carbon monoxide (CO), and nitric oxide (NO), cause serious environmental and human health problems. Diesel oxidation catalysts (DOCs) are drawing attention for their ability to eliminate such harmful exhausts effectively. Here, we report significantly improved activities of Pt-based catalysts, which are widely used as DOCs, in the oxidation of HC, CO, and NO x after Mn addition. Mn-doped Pt/Al 2 O 3 showed significantly lower light-off temperatures in the oxidation of HC, CO, and NO x than those of the unmodified Pt/Al 2 O 3 catalysts, by as much as 30 °C. The size of Pt particles was reduced from 71 nm to 33 nm after Mn addition, as evidenced by X-ray diffraction analysis and transmittance electron microscopy. Additionally, the interaction between CO and Pt on Mn-doped catalysts was weakened, and the CO adsorbed on Pt was readily oxidized even at room temperature, as confirmed by diffuse reflectance infrared Fourier-transform spectroscopy and CO temperature-programmed desorption experiments. The results of this study provide insights towards the improvement of the activity of Pt-based DOCs used for HC, CO, and NO x oxidation, by enhancing the fundamental understanding of the Pt nature promoted with Mn. [Display omitted] • Manganese improved activities of Pt-based catalysts in HC, CO, and NO x oxidation. • The size of Pt particles is significantly reduced after Mn addition. • Mn addition weakened the CO adsorption strength of Pt-based catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • 'Pt in CeO 2 ' was prepared from 'Pt on CeO 2 ' by the controlled reductive treatment. • 'Pt in CeO 2 ' displayed the high activity in the water-gas shift reaction. • The CH 4 formation was promoted on 'Pt on CeO 2 ' during the water-gas shift reaction. • 'Pt in CeO 2 ' was non-selective to CH 4 during the water-gas shift reaction. • Thin CeO 2 over-layers of 'Pt in CeO 2 ' catalyzed the water-gas shift reaction. Pt supported on CeO 2 (Pt/CeO 2) is known to be a good catalyst for the water-gas shift (WGS) reaction. However, Pt catalyzes the methanation reaction as a side reaction, which limits the usefulness of Pt/CeO 2 as a catalyst in the high-temperature (HT) WGS reaction. In this study, Pt nanoparticles (Pt NPs) were encapsulated in CeO 2 over-layers ('Pt in CeO 2 ') by using controlled reductive treatments to suppress the methanation reaction on Pt NPs. 'Pt in CeO 2 ' catalyst demonstrated the much lower CH 4 selectivity while showing the same high activity in the HT-WGS reaction compared to the conventional 'Pt on CeO 2 ' catalyst. Detailed characterizations revealed that the underlying Pt NPs promoted the WGS reaction on thin (<1 nm) CeO 2 over-layers by facilitating the formation of active oxygen vacancies. The present contribution to catalyst modification via simple thermal treatments will provide additional way to control metal-support interactions to improve catalytic performance. [ABSTRACT FROM AUTHOR]

An open-tubular radially cyclical electric field-flow fractionation technique which achieves the online separation of microparticles in a functional annular channel is proposed in this study. The system was set up by using a stainless steel tube and a platinum wire modified with ionic liquid/mesoporous silica materials as the external and internal electrodes. The feasibility for online separation of various particles was experimentally demonstrated. Particles in the channel were affected by a radial electric field and field-flow fractionation (FFF). On the cross section, different particles showed distinctive migration distances depending on their own properties and the different magnitudes of forces being exerted. The same kind of particles form an annular distribution within the same annulus while different particles form annular distributions at varied concentric annuli through electrophoresis. Under a laminar flow of FFF, different sizes of particles formed a conical arrangement within the annular separation channel. With the joint influence of electric field and flow field, different trajectories were obtained and the particles were eventually separated. Voltage, frequency and duty cycle value are the main parameters affecting the separation of particles. By adjusting these parameters, particles migrate in a zigzag trajectory on one side of the electrodes (mode I) and reach both sides of the electrodes (mode II). Six polystyrene particles were completely separated with high resolution within several minutes. Our system offers numerous advantages of label-free, high-resolution and online separation without tedious operations, and it is a promising tool for the effective separation of various micro-objects. [ABSTRACT FROM AUTHOR]

In the present study, the experimental Raman spectrum of niobium‐selenide nanowires (Nb2Se9) is reported for the first time followed by an analysis of the Raman spectrum using the density functional theory (DFT). According to the group‐theoretical analysis, 33 Ag modes were identified as Raman active modes. In the experimental spectrum, 19 well‐resolved Raman modes were observed: 13 modes in the low‐wavenumber range (50–200 cm−1) and six modes in the high‐wavenumber range (220–340 cm−1). The DFT calculations were performed using the local‐density approximation (LDA) functional and generalized gradient approximation (GGA) functional of Perdew–Burke–Ernzerhof (PBE) with van der Waals corrections (PBE‐D3). PBE‐D3 showed better compatibility with the experimental data for the high‐wavenumber range. Our results provide an essential reference for the Raman scattering of newly synthesized Nb2Se9 nanowires and nanodevices in the future. [ABSTRACT FROM AUTHOR]

The three way catalyst NOx trap catalyst (TWC-NT) is consisted of a conventional three way catalyst (TWC) compositions and NOx storage material (NSM) to mitigate NOx breakthrough occurred during the fuel cut event to improve fuel economy of stoichiometric (A/F = 14.6) gasoline powered vehicles. Typical fuel cut operation generates very lean exhaust mixture that oxidizes the catalyst surface in TWC system, and NOx is slipped on the oxygen rich catalyst surface when the engine is switched back to the stoichiometric air to fuel ratio. The fully batch formulated TWC and TWC-NT catalyst were prepared and aged on engine dynamometer equivalent to 150,000 miles at underfloor location. The aged catalysts was evaluated at LEV-3 SULEV30 passenger car to check their effects on NOx efficiency, fuel saving and N2O suppression ability. The results revealed TWC-NT showed higher NOx removal performance by 71 % with multiple the fuel cuts and O2 purge period through the thermally enhanced NOx storage and reduction function, and 2 % higher fuel economy on FTP-75 cycle than the conventional TWC. Also the catalyst had good N2O suppression ability by the removal of NOx as the main reactant of N2O formation in the exhaust gas reactions over catalyst. [ABSTRACT FROM AUTHOR]

Alloyed Ru 0.48 Re 0.52 nanoparticles uniformly grown on reduced graphene oxide performed an intensified alkaline hydrogen evolution reaction, through electronic structure regulation in terms of water dissociation and hydrogen desorption activities. [Display omitted] • Alloyed Ru 0.48 Re 0.52 nanoparticles (Ru 0.48 Re 0.52 NPs) were uniformly grown on reduced graphene oxide (rGO). • Validation of optimal synthesis and electronic structure regulation in Ru 0.48 Re 0.52 NPs@rGO was presented. • Using density functional theory (DFT), water dissociation and hydrogen desorption activities were calculated. • Intensified alkaline hydrogen evolution reaction (HER) in alloy through electronic structure regulation was confirmed. • HER activity of Ru 0.48 Re 0.52 NPs@rGO in alkaline environments exceeded that of commercial Pt/C. Converting electricity into hydrogen is vital for harnessing concentrated renewable energy. To achieve this, cost-effective electrocatalysts capable of withstanding mildly corrosive alkaline hydrogen evolution reaction (HER) conditions are necessary. Ru shows potential as a substitute for Pt-based electrocatalysts due to its comparable hydrogen bond strength. However, improvements are needed to overcome obstacles in water dissociation and hydrogen desorption during alkaline HER. In this work, Ru was alloyed with Re which is water dissociation-efficient to induce a redistribution of electron density in Ru 0.48 Re 0.52 nanoparticles (NPs). These Ru 0.48 Re 0.52 NPs exhibited superior hydrogen desorption, outperforming Pt, highlighting their effectiveness in HER. The Re component received electrons from adjacent Ru while maintaining low energy barriers for water decomposition. Additionally, self-aggregation of Ru 0.48 Re 0.52 NPs was prevented by incorporating reduced graphene oxide (rGO) support, resulting in improved conductivity and electrochemical durability in Ru 0.48 Re 0.52 NPs@rGO. Through various analyses, the optimal synthesis and electronic structure adjustments in Ru 0.48 Re 0.52 NPs@rGO were confirmed, which exhibited remarkable HER overpotentials with values of 14 and 74 mV at current densities of 10 and 100 mA cm−2, respectively, in a 1 M KOH solution. These findings establish Ru 0.48 Re 0.52 NPs@rGO as a universal approach for designing efficient electrocatalysts for HER, surpassing both the activity and cost of commercialized Pt/C. [ABSTRACT FROM AUTHOR]

A novel method that selectively polymerizes pyrrole on the silica surface without inducing polymerization in bulk solution is developed, which is based on in situgeneration of the NO+ion as an oxidant at the silica surface. [ABSTRACT FROM AUTHOR]

Carbon-supported nanoporous palladium-iridium–zinc (NP-PdIrZn) electrocatalyst was prepared through the modification of the alcohol-reduction process following the selective dissolution of excess ZnO nanoparticles using NaOH solution. The electrocatalyst was applied successfully to the cathode for a high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC). X-ray diffraction (XRD) patterns of the NP-PdIrZn nanoparticles suggests formation of the ternary alloy and complete removal of ZnO without the formation of individual Pd, Ir, or Zn nanoparticles. Moreover, transmission electron microscopy (TEM) images displayed porous nanoparticles with an irregular shape, which was generated by removing the ZnO from the PdIrZn–ZnO nanocomposites, and was prepared by using the excessive Zn precursor. The electrochemical surface area (ECSA) of the NP-PdIrZn catalysts was estimated by cyclic voltammetry using a rotating disk electrode method , and the oxygen reduction reaction (ORR) activity was evaluated by a linear sweep method. The NP-PdIrZn catalysts showed larger ECSA and higher ORR activity than those of the PdIr and PdIrZn catalysts, which may be attributed to the increased exposed surface area by selective etching of the ZnO in the composites. Furthermore, the NP-PdIrZn catalyst exhibited excellent performance (0.66 V) in a single cell under the HT-PEMFC condition than those of the PdIr (0.58 V) and PdIrZn (0.62 V) catalysts, indicating that geometric and electronic control of Pd-based alloy can improve the single-cell performance for the HT-PEMFC. [ABSTRACT FROM AUTHOR]

The catalytic oxidation of toluene with ozone at room temperature was carried out over hierarchically ordered mesoporous catalysts (CeO 2 (meso), Mn 2 O 3 (meso), ZrO 2 (meso), and γ-Al 2 O 3 (meso)) and Al 2 O 3 with various textural properties and phases (γ-Al 2 O 3 (meso), γ-Al 2 O 3 (13 nm), and α-Al 2 O 3) to examine the effects of the nature of the catalyst on the catalytic activity. The catalysts were characterized by N 2 -physisorption measurements, powder X-ray diffraction, temperature programmed reduction, X-ray photoelectron spectroscopy and scanning transmission electron microscopy with energy dispersive spectroscopy. Among the ordered mesoporous catalysts, γ-Al 2 O 3 (meso) had the highest toluene removal efficiency because of its highest surface area and pore volume, which in turn was selected for further investigation. Manganese (Mn) was introduced to various Al 2 O 3 to improve the toluene removal efficiency. Comparing the Mn-loaded catalysts supported on various Al 2 O 3 with different crystalline phases or pore structures, Mn/γ-Al 2 O 3 (meso), had the highest catalytic activity as well as the highest CO 2 /CO ratio. The higher activity was attributed to the larger surface area, weaker interaction between Mn and Al 2 O 3 , and larger portion of Mn 2 O 3 phase. The increase in ozone concentration led to an improvement in the carbon balance but this enhancement was insufficient due to the deposition of by-products on the catalyst. After long term tests at room temperature, the reaction intermediates and carbonaceous deposits of the used catalysts were identified. • Ordered mesoporous materials, γ-Al 2 O 3 , CeO 2 , Mn 2 O 3 , ZrO 2 , were used. • Effect of the crystalline phase and pore structure of Mn/Al 2 O 3 was investigated. • The catalytic activity of toluene O 3 oxidation over Mn/γ-Al 2 O 3 (meso) was highest. • The reaction intermediates and carbon deposits on the used catalysts were identified. [ABSTRACT FROM AUTHOR]

Abstract For next generation Li-ion batteries, advanced electrode materials with high energy densities are mightily important issue. Since the partial oxidation of Sn with Li 2 O to form SnO x was demonstrated upon delithiation in SnO 2 anode, the additional conversion reaction has contributed that the theoretical capacity of SnO 2 can be extended from 783 to 1494 mAh g−1. Herein, with the design of additional conversion reaction, we discuss key factors for high electrochemical performances of the SnO 2 anodes through comparative analysis between nano-structured mesoporous SnO 2 and conventional bulk SnO 2 , based on synchrotron radiation-based techniques, quantitative analysis of extended X-ray absorption fine structure spectra, and bond strength calculation. In this way, we demonstrate that the mesoporous SnO 2 has a nano-engineered structure with the weakened Sn-O bond strength for inducing the enhanced reversible conversion reaction as well as the facilitated electrochemical reaction, and a void structure for relieving the severe volume changes during lithiation/delithiation. Consequently, excellent electrochemical performance through the additional reversible conversion reaction is obtained in the mesoporous SnO 2. Insight from this research enables important advance in the development of metal oxide-based anode materials by making irreversible reaction reversible, providing a realizable strategy for the design and creation of high-energy storage devices. Graphical abstract Image 1 Highlights • Comparison of electrochemical reactions between mesoporous and bulk SnO 2. • Validating the key factors for high electrochemical performances of the SnO 2 anode. • Nano-engineering and weaker Sn-O bond strength can enable the additional reaction. • A stable void structure for alleviating the large volume variations is necessary. [ABSTRACT FROM AUTHOR]

Compared to research progress on cathode materials, progress on anode materials for sodium rechargeable batteries has been relatively slow. To bring sodium rechargeable batteries to a next level, it is necessary to explore feasible anode materials as well as understand clearly the reaction mechanism during electrochemical cycling. We herein introduce mesoporous and bulk molybdenum dioxide materials, which show excellent sodium storage performances under ether based electrolyte conditions, as anodes for sodium rechargeable batteries. Moreover, the pseudocapacitive sodium storage behavior in molybdenum dioxide anodes is proposed based on a quantitative analysis of the cyclic voltammetry responses. This result is systematically corroborated by using synchrotron radiation based analyses, X-ray photoelectron spectroscopy, scanning transmission electron microscope and ab initio molecular dynamics simulation. Comprehensive information on the electrochemical characterization as well as sodium storage mechanism of this transition metal oxide will provide a practical strategy to further advance anode materials for sodium rechargeable batteries. [ABSTRACT FROM AUTHOR]

In order to develop high energy density Li rechargeable batteries, nano-sized materials have attracted attention as the active materials. Mesoporous materials consist of the micrometre-sized particles, and they have high surface area due to their mesopore and thin wall thickness of framework. Here, we synthesize a highly ordered mesoporous RuO 2 to investigate the effect that the mesoscopic structure has on the capacity and their corresponding reaction mechanism of Li rechargeable battery. The synthesized mesoporous RuO 2 shows an initial discharge capacity of 1366 mAh g −1 on mesoporous RuO 2 , which is higher than that of commercial RuO 2 . Our findings via In situ X-ray analysis techniques combined with electrochemical analysis demonstrate that the additional capacity of mesoporous RuO 2 is resulted from the enhanced interfacial reaction between Ru metal and Li 2 O formed by conversion reaction of RuO 2 . Nano-size effects of mesoporous structure such as high surface area, easy electron transport, and small domain would enable to improve the interfacial reaction of highly ordered mesoporous RuO 2 . The understanding of this relationship between structural engineering and electrochemical properties provides the insight into development of high energy density anode materials in next generation Li rechargeable battery. [ABSTRACT FROM AUTHOR]

Pd-based core-shell alloy-supported catalysts were prepared sequentially via a microwave-assisted polyol method and galvanic replacement. To investigate the effect of the core composition on the catalytic activity of such catalysts, three different Pd alloy cores (PdNi, PdCu, and PdNiCu) were prepared on carbon supports using a polyol method. Then, Pd and Ir were introduced simultaneously to form shells on the Pd alloy cores by galvanic replacement in aqueous solution, thereby producing catalysts designated as PdNi@PdIr/C, PdCu@PdIr/C, and PdNiCu@PdIr/C. X-ray diffraction revealed that all three catalysts exhibited the face-centered cubic structure of Pd without the presence of individual phases for Ni, Cu, and Ir. The core-shell structure of the Pd-based alloy nanoparticles on the carbon support was verified by the electron energy loss spectroscopy line profile of a 25 nm nanoparticle of PdNiCu@PdIr/C. Among the three Pd-based core-shell catalysts, the highest electrochemical surface area and oxygen reduction reaction (ORR) activity was observed for PdNiCu@PdIr/C. In addition, the membrane electrode assembly employing the PdNiCu@PdIr/C catalyst displayed a significantly improved voltage compared to the other two catalysts under high-temperature polymer electrolyte membrane fuel cell conditions at 150 °C. Single-cell durability tests conducted to measure the voltage change at a constant current density of 0.2 A cm −2 showed a decay ratio of 12.3 μV h −1 . These results suggest that the composition of the core in core-shell nanoparticles has an important influence on both the electronic properties in the Pd alloy core and compressive lattice strain on the PdIr shell. Control of these synergistic effects provides a new approach for developing catalysts with high ORR activity. [ABSTRACT FROM AUTHOR]

Optimized porous structure is a prerequisite for high performance Li‒O 2 battery cathode. Macroporous-mesoporous carbon (MMC) is fabricated via a nano-replication method using mesoporous SiO 2 (KIT-6) containing NiO as the template. By varying the amount of NiO in the KIT-6/NiO composite template, the amount of macropores inside MMC is easily controlled. The as-prepared MMC exhibits a highly porous structure with abundant ordered mesopores along with macropores that are larger than 200 nm in size. When the MMC is applied as the cathode material in a Li‒O 2 battery, the cell exhibits greatly improved electrochemical performance in comparison to a cell using conventional ordered mesoporous carbon (OMC) without macropores. Systematic studies indicate that while mesopores in the OMC are clogged with Li 2 O 2 formed during the early stage of discharge, the MMC sufficiently accommodates a large amount of Li 2 O 2 in the pores. In addition, Li 2 O 2 with poor crystallinity forms on the cathode containing MMC during subsequent discharge processes, which can be due to the accumulated side product and the limited size of pores. The formation of amorphous Li 2 O 2 and the expedited mass transport through the interconnected meso- and macropores of MMC can attribute to the improved electrochemical performance of the MMC cathode material. [ABSTRACT FROM AUTHOR]

Abstract: Mesoporous silica KIT-6-, SBA-15-, and MCM-41-supported Ni catalysts (Ni/KIT-6, Ni/SBA-15, and Ni/MCM-41) were prepared via impregnation method and studied for CO2 reforming of CH4. The catalysts were characterized by X-ray diffraction analysis, N2 physisorption measurements, scanning electron microscopy, transmission electron microscopy, and temperature-programmed oxidation (O2-TPO). The Ni/KIT-6 catalyst exhibited higher catalytic activity and long-term stability compared with Ni/SBA-15 or Ni/MCM-41. The conversion of CH4 and CO2 over Ni/KIT-6 was 99 and 99 %, respectively. The superior catalytic behavior of Ni/KIT-6 is closely related to the large-pore cubic Ia3d structure of KIT-6, which enhanced dispersion of Ni nanoparticles, reduced carbon deposition, and increased diffusion of reactant and products.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Oxidative desulfurization (ODS) of organic compounds containing sulfur element from a model oil was performed using tungsten oxide catalysts supported on mesoporous silica with cubic Ia3d mesostructure, well-defined mesopores (7.2 nm), high surface area (719 m2/g), and three-dimensional pore network (WOx/KIT-6). The prepared WOx/KIT-6 catalysts (5-20 wt% WOx) were characterized by X-ray diffraction analysis, N2 sorption measurements, electron microscopy, H2-temperature programmed reduction, Raman spectroscopy, and thermogravimetric analysis. Among the mesoporous catalysts, 10 wt% WOx/KIT-6 exhibited the best catalytic performance. Sulfur-containing organic compounds, such as dibenzothiophene, 4,6-dimethyldibenzothiophene, and benzothiophene, were completely (100 %) removed from the model oil over 10 wt% WOx/KIT-6 catalyst in 2 h. In addition, the catalyst could be reused several times with only slight decrease in catalytic activity. [ABSTRACT FROM AUTHOR]

Strong adsorption of phenolics on zeolite acid sites causes high trapping inside zeolite channels and low catalytic activity of zeolite-supported catalysts in atmospheric pressure hydrodeoxygenation (HDO) of lignin-derived phenolics. This adsorption is more severe at low temperatures, and restricts the atmospheric HDO of phenolics to high reaction temperatures. The purpose of this research was to develop a catalyst with low phenolic trapping potential and high HDO efficiency under mild reaction conditions. Among the tested catalysts (Fe/HBeta, FeReOx/HBeta, Fe/MCM-41, ReOx/MCM-41, FeReOx/MCM-41, Fe/ZrO2 and FeReOx/ZrO2), the novel catalyst of FeReOx/ZrO2 exhibited the highest catalytic efficiency for mild-condition (pressure: 1 atm and temperature ＜350 °C) HDO of phenolics (guaiacol, m-cresol and anisole), and led to the selective production of BTX aromatics. Compared to Fe/HBeta(38) as a zeolite-supported catalyst, FeReOx/ZrO2 displayed remarkably enhanced performance, and its catalytic activity for the HDO of m-cresol at 350 °C was almost twice higher than that of Fe/HBeta(38) at 500 °C. Importantly, FeReOx/ZrO2 revealed a high HDO efficiency (BTX yield of 50.5 wt% with phenolic trapping below 5 wt%) at a low temperature of 250 °C, while Fe/HBeta(38) almost lost its entire catalytic activity at this temperature, and gave a low BTX yield of 3.0 wt% with a high trapped phenolic yield of 83.1 wt%. The remarkable catalytic activity of FeReOx/ZrO2 in the HDO of phenolics at atmospheric pressure and temperatures as low as 250 °C is a result of its mesoporosity and oxophilicity as well as its well-balanced acidity induced by both rhenium oxide and zirconia support causing a high dehydration efficiency. [ABSTRACT FROM AUTHOR]

This study focused on the effect of the incorporation of aluminum on the catalytic performance of KIT-6 in the norbornadiene cyclodimerization reaction. An Al-KIT-6 material synthesized through Al grafting over siliceous KIT-6 was shown to have a well-ordered mesoporous structure and a large pore size. The grafting of Al onto siliceous KIT-6 generated weak acid sites consisting of Lewis acid sites and Brönsted acid sites. Cyclodimerization of norbornadiene was carried over Al-KIT-6 catalysts in a batch reactor in order to compare their activity with that of the Al-MCM-41 catalyst. The activity of norbornadiene cyclodimerization over the Al-KIT-6 catalyst was higher than that over the Al-MCM-41 catalyst, which could be attributed to the larger pore diameters of the Al-KIT-6 catalyst. The acidity and the catalytic activity of the Al-KIT-6 catalyst as used here could easily be recovered through filtering and calcination in an air atmosphere at 550 °C. [ABSTRACT FROM AUTHOR]

We describe the synthesis and characterization of hierarchically porous organic-inorganic hybrid silica with periodic 2-D hexagonal order and tunable location of secondary nanopores through co-condensation of tetraethylorthosilicate (TEOS) and a new type of amphiphilic organosilicate precursors. Our amphiphilic organosilicates offer unique tunability of secondary micropores by carefully controlled bond molecular structure and number of bonds between hydrophobic adamantylphenols pore-generating moieties and siloxane precursors. Small angle X-ray scattering (SAXS) and microscopy results show a good structural order of the organic-inorganic hybrid silica. In addition, 29 Si CP-MAS NMR spectra confirm the successful incorporation of organosilicate precursors into a silica framework. The primary cylindrical mesopores (∼6.4 nm) were originated from the cooperative self-assembly of Pluronic P123 triblock copolymer templates while smaller meso-/micropores were derived from adamantylphenols groups. We have previously demonstrated that adam-graft SQ had an affinity for hydrophobic PO core blocks to be located close to PO segment, which resulted in small pores next to primary mesopores and the resultant increment of mesopore size as well as wrinkled silica walls. On the contrary, the secondary small pores were mainly generated within a silica network while the size of the primary mesopores unaffected with the addition of adam-bridge SQ due to its selective incorporation into a silica framework. Moreover, the organic-inorganic hybrid silica prepared with adam-bridge SQ showed higher thermal stability than that of adam-graft SQ and SBA-15 type mesoporous silica. It is attributed to more Si O Si bonds formed from the bridged structure as well as enhanced hydrogen-bonding interaction between adam-bridge SQ hybrid silica and P123 templates. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrocatalytic Re nanoflowers (Re NFs) were grown on a carbon cloth (CC) substrate. • Optimal synthesis and growth mechanism of Re NFs on CC were validated. • Density functional theory (DFT) calculations determined intrinsic HER activity of Re. • Hydrogen evolution reaction (HER) activity of Re in different pH environments was evaluated. • ReNF@CC performed eminent HER activities with significantly reduced overpotentials. The hydrogen evolution reaction (HER) is one of the primary routes for clean hydrogen energy production to replace fossil fuels. However, the lack of cost-effective electrocatalysts hinders its practical implementation. Re, which is considerably less expensive than Pt, has recently emerged as an electrocatalyst owing to its high HER activity over a wide pH range. However, HER processes of Re have been studied primarily through spectroscopy, with little theoretical interpretation to explain the intrinsic HER activity of Re. Additionally, it is necessary to develop antioxidative Re electrocatalysts to prevent hydrogen intercalation, and to suppress catalyst aggregation to ensure long-term stability. In this work, a theoretical analysis was first conducted to investigate the free energy of each HER intermediate and demonstrate high performance of Re. Then, a novel free-standing electrocatalyst consisting of Re nanoflowers (NFs) grown in-situ on a carbon cloth (CC) was synthesized (ReNF@CC) via a hydrothermal method followed by thermal annealing. The Re NFs homogeneously grown on the CC surface effectively suppressed self-aggregation to preserve abundant active sites, and the direct coupling of Re NFs enhanced the conductivity and physical/electrochemical stability to prevent their detachment from the CC during operation. A high HER performance was obtained with low overpotentials of 103, 115, and 75 mV at 10 mA cm−2 in 0.5 M H 2 SO 4 , 1 M PBS, and 1 M KOH, respectively; additionally, a superior durability with respect to commercial Pt/C was achieved. Overall, this study offers a versatile and universal strategy for highly efficient water electrolysis in different media. [ABSTRACT FROM AUTHOR]

We developed highly promising solid polymer electrolytes (SPEs) based on a novel cross-linker containing star-shaped phosphazene with poly(ethylene oxide) (PEO) branches with very high ionic conductivity (7.6 × 10 −4 S cm −1 ), improved mechanical stability, and good electrochemical stability for all-solid-state lithium batteries. In particular, allyl groups were introduced at the ends of the cross-linker in order to overcome the easy self-polymerization of existing cross-linking acrylate end groups. A novel semi-interpenetrating network (semi-IPN) SPE was prepared by in-situ radical polymerization of a precursor solution containing lithium salt, poly(ethylene glycol) dimethyl ether as a plasticizer, and a mixture of pentaerythritol tetrakis(3-mercaptopropionate) and a synthesized hexakis(allyloxy)cyclotriphosphazene ( thiol-ene PAL) as the cross-linker. Batteries employing LiFePO 4 as the cathode, lithium foil as the anode, and the SPE thin film as the electrolyte were assembled and tested. At ambient temperature, the initial discharge capacity was 147 mAh/g at 0.1 °C and 132 mAh/g at 0.5 °C, and 97% of the capacity was retained at the 100th cycle. All-solid-state pouch-package lithium cells assembled with the SPEs exhibited stable electrochemical performance, even under a severely wrinkled state. These outstanding properties of SPEs based on thiol-ene PAL demonstrate feasibility for practical battery applications with improved reliability and safety. [ABSTRACT FROM AUTHOR]

The Phase pure wurtzite structured ZnO phosphor was prepared by sintering three different precursors viz. zinc acetate, zinc nitrate, and ZnO at 800 °C, 900 °C, and 1000 °C in a reducing atmosphere for 1 h. The prepared ZnO phosphor samples were characterized by powder X-ray diffraction and the Rietveld refinement analysis in order to study their structural information that confirms their wurtzite hexagonal phase. Scanning electron microscopy (SEM) pictures exhibited irregular spherical morphology with an average particle size between 1 and 3 μm. The corresponding EDAX spectrum confirmed the presence of Zn and O species. Dependence of sintering temperature on the photoluminescence (PL) properties of ZnO samples and their enhancement on deep-level emission were studied. Deep level green emission around 505 nm was observed for the ZnO samples sintered in the reducing atmosphere without adding any impurities. Among three samples, the maximum PL emission intensity and better CIE colour coordinates under 380 nm excitation were obtained for the ZnO sintered at 900 °C and 1000 °C. Maximum Entropy Method (MEM) were used to determine the electron distributions in the unit cell which supports the PL investigation. [ABSTRACT FROM AUTHOR]

Lithiation-delithiation reactions in Li-ion batteries do exhibit a huge electrochemically driven volume change of the anode material between the lithium-free and lithiated-host states, which results in a gradually fading capacity. Minimizing this volume change of the electrode during cycling is essential to achieve stable electrochemical behavior and thus for innovating design of electrode materials for Li storage. Here, ordered mesoporous CoSn intermetallic anode materials with various Co/Sn atomic ratios are developed. A dual-buffer effect is discovered that accommodates the volume changes in the electrode material by not only repeatedly generating void nanospaces but also by incorporating electrochemically inactive elements. Novel insights into the nanostructural changes of electrode materials during the lithiation-delithiation process are obtained by in operando small angle X-ray scattering. The degrees of volume change and nanoscopic order are found to be highly dependent on the Co contents in the mesoporous CoSn intermetallic anode materials, being possible to achieve a durable nanostructured electrode upon prolonged cycling. [ABSTRACT FROM AUTHOR]

A nano-composite of ordered mesoporous carbon (OMC) and silicon carbide (SiC) was investigated as a durable support for Pt nanoparticles, in order to improve the electrochemical activity and stability in oxygen reduction reaction (ORR). The OMC and OMC–SiC were synthesized via a nano-replication method, using ordered mesoporous silica as a template and 1,10-phenanthrolline as a carbon source at temperatures of 900 and 1350, respectively. Non-porous SiC material was obtained by heat treatment at 1600 °C. The OMC–SiC composite, containing 10.3 wt% of SiC, exhibited a high surface area (568 m 2 /g) and well-defined mesopores (2.7 nm). Highly dispersed Pt nanoparticles were supported on both the OMC and the OMC–SiC, using a polyol method. The ORR activity and the electrochemical surface area (ECSA) of Pt/OMC, Pt/OMC–SiC and commercial Pt/C catalysts were measured using a rotating disk electrode technique with the linear sweep method, and a potential-cycling test, respectively. The Pt/OMC–SiC composite showed the highest activity as well as the highest durability for ECSA and ORR, which may be attributed to the effect of the intimate hybridization of SiC with the OMC in nanoscale. These results indicate that the OMC–SiC composite is a very promising support material for electrochemical catalysts in fuel cells. [ABSTRACT FROM AUTHOR]

Highly ordered mesoporous antimony-doped tin oxide (ATO) materials, containing different amount of antimony in the range of 0-50mol%, are prepared via a nanoreplication method using a mesoporous silica template. The mesoporous ATO materials thus obtained exhibit high electrical conductivity, high reversible capacity, superior cycle stability and good rate capability as anode materials for lithium-ion batteries, compared to those of pure mesoporous tin oxide. Amongst the ATO materials in this work, the mesoporous ATO material with 10mol% of antimony has highest discharge capacity of 1940mAhg-1 (charge capacity of 1049) at the 1st cycle, best cycle performance (716mAhg-1 at 100th cycle) and excellent rate capability, which are probably due to the enhanced electrical conductivity as well as reduced crystalline size. Ordered mesoporous antimony-doped tin oxide (ATO) materials with Ia3d mesostructure were obtained using nanoreplication method. The electrical conductivity of meso-ATO-10 is drastically enhanced, compared to that of meso-ATO-0. Moreover, the Sb-doping results in the high capacity retention (67% at 100th cycle) as well as excellent rate capability. We believe that the Sb-doping reduces the possibility of aggregation of the metallic tin toward larger crystals and accommodates the electrochemically induced volume change during Li alloying-dealloying process. [ABSTRACT FROM AUTHOR]

We report on a facile synthesis of the ordered mesoporous carbon (OMC) materials with systematically controlled microporosity and mesoporosity simultaneously through the nano-replication route using phosphoric acid as the acid catalyst and activation agent. The use of phosphoric acid affects the pore structures of OMC materials, such as the formation of numerous micropores by activation of the carbon framework and the enlargement of mesopores by spontaneous phase separation during the carbonization. The mesopore sizes, surface areas, total pore volumes, and micropore volumes of the OMC materials are highly dependent on the phosphoric acid content and can be systematically controlled in the range 3.7-7.5 nm, 1027-2782 m2 g-1, 1.12-3.53 cm3 g-1 and 0.34-0.95 cm3 g-1, respectively. OMC materials with systematically controlled pore structures were successfully synthesized using phosphoric acid as the carbonization catalyst and mesoporous silica materials with cubic Ia3 d and 2-D hexagonal mesostructures as the templates. The phosphoric acid in the synthesis of ordered mesoporous carbon materials acts as the chemical activating agent for micropore generation of the carbon framework and pore-expanding agent for controlling of mesopore size, in addition to functioning as the acid catalyst. The present synthesis pathway is very useful for preparing OMC materials with tunable mesopore sizes and well-developed microporosities at the same time. [ABSTRACT FROM AUTHOR]

Highly ordered mesoporous tungsten trioxide (WO3) with high surface area (75 m2/g) and well-defined mesopores were successfully prepared through a hard templating method using a mesoporous silica KIT-6 as a template and (NH4)6H2W12O40 ⋅ xH2O as a tungsten precursor. Oxidative desulfurization of a model oil with H2O2 as the oxidant was carried out at 50°C under atmospheric pressure in order to analyze the catalytic activity. The desulfurization reactions were optimized by various kinds of reaction parameters such as H2O2/S molar ratio, reaction temperatures and series of sulfur-containing compounds [dibenzothiophene (DBT), benzothiophene (BT) and 4,6-dimethyl dibenzothiophene (4,6-DMBT)]. Excellent catalytic activity for the removal of the sulfur-containing compounds from the model oil was observed with mesoporous WO3 catalyst, where the activity was maintained during 5 recycle tests without any regeneration process. The high catalytic activity and durability is mainly attributed to well-defined mesopores and high surface area of mesoporous WO3 catalyst. [ABSTRACT FROM AUTHOR]