Search

In this paper, we investigate the properties of well-rounded twists of a given ideal lattice of an imaginary quadratic field K. We show that every ideal lattice I of K has at least one well-rounded twist lattice. Moreover, we provide an explicit algorithm to compute all well-rounded twists of I. [ABSTRACT FROM AUTHOR]

The viability of converting wood chips and plastic to power via compact integrated catalytic fast/slow pyrolysis, combustor, and Stirling engine technologies was determined using modeling analysis. Aspen simulations followed by sizing analysis were performed to determine the size, weight, and net energy efficiency of upgrading wood chips and plastic to power using a compact energy system with a feedstock processing capacity of 1 kg h−1. The equipment and tooling to fabricate individual components of a compact energy system were identified. The total costs of fabricating all the individual components of compact energy systems were assessed. A discounted cash flow analysis with an internal rate of return of 20% was used to assess the minimum selling price of compact energy systems. The specific energy (Wh kg−1) of the compact catalytic fast pyrolysis system, compact slow pyrolysis system, and compact plastic conversion system were assessed at 20, 29, and 63, respectively. The assessed capital and annual costs of manufacturing 10 000 compact energy systems per year were $51 million and about $11 to $13 million, respectively. The calculated minimum selling price of a catalytic fast pyrolysis system, a compact slow pyrolysis system, and a compact plastic conversion system were $3055, $3021, and $2980, respectively. The sensitivity analysis results showed that the internal rate of return, capital investment, materials cost, annual operating costs, and capital cost have significant impacts on the minimum selling price of compact energy systems. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Abstract Titanium silicalite-1 (TS-1) nanosheets can be synthesized from the precursor gels containing a diquaternary ammonium template in hydroxide form. The TS-1 nanosheets tend to form unilamellae interconnected in disordered aggregates. Pillaring of TS-1 nanosheets preserves the mesoporosity, but lacks long-range order of nanosheet layers. Here, we report synthesis of multilamellar TS-1 (M-TS-1) with long-range order of nanosheet layers from the precursor gels containing hexanediamine (C 6 DN) and diquaternary ammonium template in bromide form (C 22-6-6 Br 2). Pillaring of M-TS-1 produced pillared TS-1 (P-TS-1) with well-preserved mesoporosity and long-range order of layers. The influences of concentrations of C 22-6-6 Br 2 , C 6 DN, and Ti precursor as well as crystallization time, on the resultant M-TS-1 were investigated. The physicochemical properties of the M-TS-1 and P-TS-1 were studied and compared to the conventional TS-1 zeolite. The presence of mesopores in P-TS-1 enhanced the catalytic performance in reactions involving bulky molecules. Graphical abstract Image 1 Highlights • Multilamellar TS-1 with long-range ordering structure was synthesized from hexanediamine and Gemini-type bromide templates. • Pillared TS-1 with long-range order of zeolite nanosheet layers was achieved. • Influences of concentrations of templates and Ti precursor, crystallization time on the multilamellar TS-1 were investigated. • Mesopores in pillared TS-1 enhanced the Lewis acid sites accessibility and catalytic performance involving bulky molecules. [ABSTRACT FROM AUTHOR]

Abstract Hierarchical lamellar zeolites, comprised of both micro- and mesoporosity, afford high active site accessibility and mass transport in processing of bulky molecules. Here, we report the synthesis of hierarchical lamellar MFI zeolites with sequential intergrowth that is induced by composition variation in the standard recipe of 100SiO 2 /0.5Al 2 O 3 /3C 22-6-6 /18.5Na 2 O/4000H 2 O, where C 22-6-6 stands for the diquaternary ammonium surfactant ([C 22 H 45 N+(CH 3) 2 C 6 H 12 N+(CH 3) 2 C 6 H 13 ]Br− 2) template. The influences of C 22-6-6 concentration, alkalinity, and aluminum amount on the intergrowth of hierarchical lamellar MFI zeolites were investigated. The consequences of intergrowth on mesoporosity were analyzed. In all studied synthesis conditions except for very low alkalinity, hierarchical lamellar MFI zeolites were successfully crystallized. The increasing template concentration in the synthesis gel resulted in an increase in intergrowth and thus mesoporsotiy in the hierarchical MFI products. The increasing alkalinity led to an increase and then a decrease in mesoporosity in the hierarchical MFI products, which reflects the same trend in intergrowth in the hydrothermal synthesis process. The aluminum concentration, however, did not significantly affect the intergrowth and mesoporosity of the resultant hierarchical MFI zeolites. The sequential intergrowth achieved by simple variation in the synthesis composition for lamellar MFI zeolites resulted in higher structure hierarchy, mesoporosity, and acid site accessibility in one-step. Graphical abstract Image 1 Highlights • Hierarchical lamellar MFI zeolites were synthesized in one-step. • Intergrowth enhanced mesoporosity in hierarchical lamellar MFI zeolites. • Intergrowth increased with increasing surfactant template content in synthetic gel. • Intergrowth increased and then decreased with alkalinity in synthetic gel. • Aluminum content in synthetic gel did not influence intergrowth noticeably. [ABSTRACT FROM AUTHOR]

Abstract Volume swelling is a typical mode of battery failures, which happens not only in the operation but also during the storage of rechargeable batteries as a result of electrolyte degradation, particularly the chemical oxidation of electrolyte solvents by the active oxygen released in phase transition of the layered cathode materials. Aiming to remove the active oxygen, we herein propose Pyrite FeS 2 powder as an in-situ oxygen remover based on the fact that FeS 2 can be ultimately oxidized to Fe 2 O 3 and Li 2 SO 4 by the active oxygen, and the redox reaction depletes considerable amount of oxygen. By mixing FeS 2 powder into a conventional LiNi 0.80 Mn 0.10 Co 0.10 O 2 (NMC811) cathode, it is found that under normal cycling conditions of the Li/NMC811 cells, FeS 2 is electrochemically stable while being capable of reacting with active oxygen and hence stabilizing the cell's capacity retention. The concept proposed in this work provides a practically viable and cost-effective approach for preventing volume swelling of the rechargeable batteries based on the layered cathode materials. Graphical abstract Image 1 Highlights • Phase transition and oxygen release is an intrinsic nature of layered cathode materials. • Pyrite FeS 2 is proposed as an in-situ oxygen remover for rechargeable batteries. • In battery FeS 2 is electrochemically stable and capable of removing active oxygen. • FeS 2 suppresses impedance growth and the 2nd structure crack of layered cathode materials. [ABSTRACT FROM AUTHOR]

The synthesis of hierarchical meso-/microporous zeolite materials with spatially controlled morphology, meso-/microporosity, and acidity is an expanding area of research interest for a wide range of applications. Here, we report a one-step dual template synthesis method for integration of 3-dimensional (3D) BEA nanosponge and ultra-thin 2D lamellar MFI into a new type of hierarchical meso-/microporous zeolite composite structures. Specifically, the 2D layered MFI nanosheets were laid over the surface of or interdigitated into the 3D BEA particles in the bulk BEA nanosponge-lamellar MFI (BBLM) zeolite structure, which generated a unique morphology of interconnected micropores and mesopores underneath the ‘skinning’ shell (∼3–10 nm) of MFI nanosheets. The BBLM zeolites have higher mesoporosity than either bare BEA or lamellar MFI zeolites. The micropore size decreases with increasing lamellar MFI component in the composite. The fraction of external acid sites of BBLM zeolite composite, represented by the percentage of active sites accessible to bulky organic base molecules, decreases with increasing MFI component. Additionally, the types of acid sites are diversified in the BBLM composites compared to either bare BEA or lamellar MFI zeolites. The catalysis tests using conversion of benzyl alcohol in mesitylene showed that BBLM zeolites had significant higher activity and durability than single zeolites or their physical mixture. The BBLM zeolite composite provides a good model catalyst with integrated 2D-3D structures and meso-/microporosity for studying a series of important catalytic reactions in hierarchical zeolites. The one-step dual template synthesis method described herein is versatile and facile, which may prove to be a general platform for hierarchical zeolite composite design at the unit-cell scales of zeolites and with potentially broader applicability to other porous materials. [ABSTRACT FROM AUTHOR]

Background: Heart failure is a costly health condition and a major public health concern. We sought to examine the costs of hospital admissions for heart failure between fiscal years 2004 and 2013 in Canada and to model the future costs to 2030. Methods: Canadian Institutes for Health Information Discharge Abstract Database was used to identify admissions to hospital with heart failure as the primary diagnosis between fiscal years 2004 and 2013. Multiple linear regression models were used to calculate the trend in prevalence and extrapolate these to 2030. Canadian Institutes for Health Information patient cost estimates were used to identify costs of hospital admissions for heart failure. Generalized linear models were used to estimate average annual costs per heart failure patient. We conducted a sensitivity analysis including all admissions for heart failure in any diagnostic field. Results: In 2013, 45 600 (95% confidence interval [CI]: 43 800-47 200) patients were admitted with heart failure as the primary diagnosis, accounting for $482 (95% CI $464-$500) million. By 2030, we estimate 54 000 (95% CI 49 000-60 000) patients and costs of $722 (95% CI $650-$801) million, with older adults (age ≥ 80 yr) accounting for 52% of costs. Including admissions for which heart failure was a secondary diagnosis increases the total cost to $2.8 (95% CI $2.6-$3.0) billion in 2030. Interpretation: As in other developed countries, hospital costs related to heart failure in Canada are on the rise. Older adults are the main consumers of such hospital services. Strategies to improve outpatient care to reduce rates of admission for heart failure are needed. [ABSTRACT FROM AUTHOR]

• Pt/TiO 2 catalysts with different Pt aggregation sizes were prepared. • Hydrogenation activity of Pt/TiO 2 showed a volcano-shaped trend with Pt sizes. • Pt activity ranks in the order of nanometer cluster > nanoparticle > single atom. • Relationships between Pt activity and structural/electronic property were discussed. Supported metal catalysts often consist of metal sites ranging from nanoparticles to subnanometer clusters and single atoms. It remains a necessity to differentiate these sites to guide design of optimal catalysts. Here we report a simple method to assess the distribution of metal active sites in catalyst samples. The method takes the advantage of the structure sensitivity of styrene hydrogenation over titania supported platinum (Pt) catalysts with Pt aggregates varied from single atom to ∼1.40 nm nanoparticles. The physicochemical properties were characterized by STEM, XPS, XANES, H 2 -TPR and CO-chemisorption measurements. The reactivity of Pt sites was quantified by styrene hydrogenation at ambient conditions. The nanometer-sized Pt clusters have significantly higher activity than Pt nanoparticles, sub-nanometer clusters or isolated single atoms. The relationship between activity and structural/electronic properties of Pt sites influenced by particle sizes was discussed. Similar relationship was found in the carbon supported Pt catalysts. [Display omitted] [ABSTRACT FROM AUTHOR]

The redox mechanism of micro-sized FeS 2 particles in a rechargeable lithium battery is studied by galvanostatic cycling and ac-impedance analysis. It is shown that FeS 2 is irreversibly reduced on the first discharge, turning Li/FeS 2 cell into a combination of Li/FeS and Li/S chemistries, as suggested by two distinct discharge plateaus at ∼1.5 and 2.0 V, respectively. The first discharge consists of an irreversible conversion of FeS 2 to Li 2 FeS 2 intermediate and its subsequent reduction to metallic Fe and Li 2 S. The first discharge suffers an initial voltage delay, suggesting that the discharge progresses in a thermodynamic non-equilibrium condition. The initial voltage delay can be attributed to the large grain boundary resistance (GBR) of pristine FeS 2 particles, which impedes the nucleation of a new solid Li 2 FeS 2 phase causing high polarization. Ac-impedance spectra of the FeS 2 cathode are composed of a semicircle and a straight sloping line, representative of an electrode reaction resistance (R er ) and a Li + adsorption impedance, respectively. The R er is found to decrease progressively during the first discharge and reaches a plateau when the cell is charged above 2.5 V vs. Li/Li + , being consistent with the model that FeS 2 is irreversibly reduced during the first discharge and that the Li 2 S/Li 2 S n redox couple is formed in recharge. It is indicated that Li/FeS 2 batteries face the same problems as Li/S batteries, such as the dissolution of lithium polysulfide, the formation of a redox shuttle, and the loss of sulfur active material. [ABSTRACT FROM AUTHOR]

We report a series of mesoporous silicate sorbent materials templated by long-chain primary alkylamines that display record level of desulfurization of the jet fuel JP-8. Pure silica frameworks and those with a Si:Zr synthesis molar ratio ranging from 44:1 to 11:1 were investigated. The optimum sorbent was identified as dodecylamine-templated silica-zirconia synthesized from a gel with Si:Zr molar ratio of 15:1. With an optimized silver loading of 11 wt.%, a saturation adsorption capacity of 39.4 mgS g −1 and a silver efficiency of 1.21 molS mol Ag −1 were observed for JP-8. This sorbent displayed exceptional regenerability, maintaining 86% of its initial capacity in model fuel after solvent regeneration with diethyl ether. Low-cost, portable and reusable sorbents for the desulfurization of JP-8 jet fuel are needed to make solid oxide fuel cells (SOFCs) a reality for military power needs. SOFCs require ultra-low sulfur content fuel, which traditional desulfurization methods cannot achieve. [ABSTRACT FROM AUTHOR]

Highlights: [•] Conventional separator is coated with a 50PEO-50SiO2 (wt.%) composite layer. [•] Composite coating increases tensile strength and electrolyte wettability. [•] Coated separator offers an alternative approach for making gel polymer Li/S battery. [•] Li/S battery takes benefits of gel polymer electrolyte at the expense of capacity. [Copyright &y& Elsevier]

Abstract: In this communication, we disclose a proof-of-concept lithium/sulfur liquid battery that has exceptionally high capacity density. In such a battery, the cathode consists of a highly porous carbon cloth (CC) as the cathode current collector and a porous sulfur paper as the source of active material. In the first discharge, sulfur is reduced on the CC surface into high order lithium polysulfide (PS), which dissolves into liquid electrolyte and serves as the catholyte of the so-called “Li/S liquid battery”. By adopting a LiNO3-contained electrolyte to protect Li anode, the Li/S liquid cell is shown to cycle reversibly between 1.7 V and 2.8 V with an initial capacity of 778 mAh g−1 S, corresponding to a capacity density of 10.1 mAh cm−2 CC, which could be the highest capacity density among the rechargeable Li/S batteries reported ever. This work reveals that the high capacity density Li/S batteries can be made through a “Li/S liquid cell” by employing a highly porous carbon electrode to accommodate the insoluble sulfur reduction products (Li2S2/Li2S) with appropriate protection of the Li anode. [Copyright &y& Elsevier]

Abstract: A nano-sized non-noble metal catalyst containing hemin supported on carbon black was synthesized for the oxygen reduction reaction (ORR). The hemin supported on carbon black was heat-treated (HT), and subjected to additional ultrasound treatments to increase the BET surface area and available active sites for the ORR. The HT hemin supported on carbon black was characterized with thermogravimetric analysis (TGA), elemental analysis, transmission electron microscopy (TEM), and BET surface area analysis. The catalytic activity of the synthesized electrocatalysts was analyzed with cyclic voltammetry (CV), rotating disk electrode (RDE), and rotating ring disk electrode (RRDE). The effect of BET surface area on formal potential, anodic and cathodic peak currents, limiting currents, half wave potentials, and kinetic rate constant for ORR were studied. We found an apparent correlation between catalytic activity and BET surface area for this particular catalyst. Increasing BET surface area, the ORR catalytic activity increases significantly. Our research on HT hemin indicates that the catalytic activity for ORR significantly improves by reducing the particle size and increasing the surface area. [Copyright &y& Elsevier]

Abstract: Applications requiring hydrogen fuel, including portable, mobile and stationary fuel cells for power generation, are increasing. The conversion of JP-8 to hydrogen offers an energy dense feedstock for hydrogen production through fuel reformation. Unfortunately, organic sulfur compounds in logistical fuels, even at part per million levels, can poison reformer and fuel cell catalysts. In this work, adsorbents based on silica supported gold ions and gold nanoparticles were synthesized and evaluated for the adsorptive desulfurization of JP-8 jet fuel. The adsorbents were evaluated with JP-8 fuel containing 430 ppmw sulfur under ambient conditions. The preparation, as well as the sulfur removal and adsorption characteristics for two adsorbents are described in this work. [Copyright &y& Elsevier]

Background: Self-administered subcutaneous immunoglobulin G (SCIg) reduces nursing time and eliminates the need for treatment at ambulatory care clinics, as compared with clinic-based intravenously administered IgG (IVIg), and are therapeutically equivalent. Estimating the economic impact of self-administered SCIg versus clinic-administered IVIg therapy may guide treatment recommendations. Methods: A retrospective population-based cohort study using administrative data from Alberta was performed; those treated with IgG between April 1, 2012 and March 31, 2019 were included. Costs for medical laboratory staff and nursing time, as well as ambulatory care visits were considered. Univariate generalized linear model regression with gamma distribution and log link was used to compare cost ($CDN 2020) between SCIg and IVIg administration. Stratified analysis by age (≥ 18-years; < 18-years) was performed. Results: Among 7,890 (6,148 adults; 1,742 children) individuals who received IgG, the average administration cost per patient-year of self-administered SCIg was $5,386 (95% confidence interval [CI] $5,039, $5,734) lower than clinic-administered IVIg; per patient-year cost of self-administered SCIg was $817 (95% CI $723, $912) versus $6,204 (95% CI $6,100, $6,308) for clinic-administered IVIg. The per patient-year cost of self-administered SCIg was $5,931 (95% CI $5,543, $6,319) lower among adults and $3,177 (95% CI $2,473, $3,882) lower among children compared with clinic-administered IVIg. An estimated $31.0 million (95% CI $29.0, $33.0) in cost savings to the health system would be realised if 80% of individuals switched from clinic-administered IVIg to self-administered SCIg. Conclusions: Self-administered SCIg is substantially less costly from a health care payer perspective in Canada. Within this type of health system, switching to self-administered SCIg has the potential to reduce overall health care costs, lessen nursing burden, and may increase clinic-based capacity for others. [ABSTRACT FROM AUTHOR]

Abstract: A bio-material, hemin, was heat-treated and used as an oxygen reduction reaction (ORR) electrocatalyst. In addition to heat-treatment, two methods were used to improve the catalysts'' electrochemical activity. First, high surface area graphene nanoplatelets (GNP) were chosen as a catalyst support. Second, ultrasound was used to break the catalyst samples into smaller pieces. Hemin supported on GNP and heat-treated at 600°C showed significantly higher catalytic activity than those without ultrasonic treatment. Furthermore, a single fuel cell fabricated with the synthesized catalyst yielded a power density of 300mWcm−2. [Copyright &y& Elsevier]

Abstract: A three-dimensional La(III) based metal-organic framework, La2[NC5H3(CO2)2]3·3H2O, was assembled using the aromatic linker 3,5-pyridinedicarboxylate. This new compound was synthesized hydrothermally and is an unusual example of a lanthanum containing metal-organic network. The compound contains two distinct La centers, each adopting a nine-coordinate geometry. The structure is built up from zig-zag chains that link via bridging water molecules into a double chain defining edge-sharing six rings. These double chains are arranged into layers and connect through 3,5-pyridinedicarboxylate ligands to give the extended 3-D coordination framework. The material is thermally stable to ca. 360°C and transforms to an unknown compound before finally decomposing to phase-pure La2O3 at 800°C. The synthesis, structure, morphology and properties of the new material are described. [Copyright &y& Elsevier]

We describe herein a three-dimensional Cu(II) based metal−organic framework, copper hydroxide 2,6-naphthalenedisulfonate, Cu3(OH)4[C10H6(SO3)2]. The compound contains embedded positively charged 2-D copper oxide layers. This higher dimensionality of inorganic connectivity leads to far greater thermal stability (375 °C vs 245 °C) over our previously reported three-dimensional metal−organic framework containing embedded 1-D cuprate chains. Single crystal data for this material are as follows: FW = 544.92, monoclinic, space group P21/c, a = 13.549(5) Å, b = 5.503(2) Å, c = 9.512(4) Å, β = 90.031(6)°, V = 709.2(5) Å3, Dc = 2.552 g·cm−3, and Z = 4. The structure, crystallinity, morphology, and properties of the material are discussed. The magnetic susceptibility exhibits a broad maximum centered at 80 K, indicative of low-dimensional antiferromagnetic interactions. Control of inorganic dimensionality embedded within an MOF is an often overlooked yet key feature in determining the stability and important properties of MOFs such as adsorption, conductivity, and magnetism. A three-dimensional Cu(II) based metal−organic framework, copper hydroxide 2,6-naphthalenedisulfonate, is described. The compound contains embedded cationic 2-D copper oxide layers, with greater thermal stability over our previously reported three-dimensional MOF containing embedded cationic 1-D cuprate chains. Control of inorganic dimensionality embedded within an MOF is an often overlooked yet key feature in determining important properties of MOFs such as adsorption, conductivity, and magnetism. [ABSTRACT FROM AUTHOR]

Abstract: A three-dimensional Bi(III) based metal–organic framework was synthesized under hydrothermal conditions using the multidentate organic linker 3,5-pyridinedicarboxylate. Bismuth oxide 3,5-pyridinedicarboxylate, Bi2O2[NC5H3(CO2)2], contains embedded 1-D cationic bismuth oxide chains that propagate along the crystallographic c-axis. The oxygens of the Bi2O2 core are three-coordinate and bond strongly to the Bi atoms. Thermogravimetric analysis shows that the material possesses high thermal stability up ca. 400°C before decomposing to phase-pure Bi2O3 at 800°C. The structure, crystallinity, morphology and properties of the material are discussed. [Copyright &y& Elsevier]

Abstract: A three-dimensional strontium-based metal-organic framework was constructed using 1,3,5-benzenetricarboxylic acid, [Sr3((OOC)3C6H3)2(H2O)4]·H2O. This new compound was synthesized hydrothermally and is a rare example of a strontium metal-organic network. The compound network contains three distinct Sr centers, one of which is seven-coordinate and the other two are nine-coordinate geometry. The benzene rings form a herring-bone type of arrangement down the a-axis. The material is thermally stable to ca. 230°C and transforms to an unknown material before finally decomposing to phase-pure SrCO3 at 650°C. The synthesis, structure, morphology and materials properties are discussed. [Copyright &y& Elsevier]

Bioimaging at molecular and cellular levels requires specific image analysis methods to help life scientists develop methodologies and hypotheses in biology and biomedicine. In particular, this is true when dealing with microscopic images of cells and vessels. To facilitate the automation of cell screening, we have developed methods based on vector quantization and Markov model for classification of cellular phases using time-lapse fluorescence microscopic image sequences. Because of ambiguity inherently existing in the labeling of cell-phase feature vectors, we proposed to use relaxation labeling technique to reduce uncertainty among cell-phase models having overlapping properties. To further improve the classification rate we applied a fuzzy fusion strategy for combining individual results obtained from multiple classifiers. Our proposed image-classification methods can be useful for the task of high-content cell-cycle screening which is essential for biomedical research in the study of structures and functions of cells and molecules. [ABSTRACT FROM AUTHOR]

Advances in fluorescent probing and microscopic imaging technology provide important tools for biomedical research in studying the structures and functions of cells and molecules. Such studies require the processing and analysis of huge amounts of image data, and manual image analysis is very time consuming, thus costly, and also potentially inaccurate and poor reproducibility. In this paper, we present and combine several advanced computational, probabilistic, and fuzzy-set methods for the computerized classification of cell nuclei in different mitotic phases. We tested our proposed methods with real image sequences recorded over a period of twenty-four hours at every fifteen minutes with a time-lapse fluorescence microscopy. The experimental results have shown that the proposed methods are effective for the task of classification. [ABSTRACT FROM AUTHOR]

A three-dimensional Cu(II) metal-organic framework, copper hydroxide p-pyridinecarboxylate hydrate, [Cu(OH)(C5H4NCO2)·H2O], was synthesized by hydrothermally reacting copper nitrate with p-pyridinecarboxylic acid. The crystals were suitable for single-crystal X-ray diffraction analysis, which showed that the Cu(II) centers adopt a slightly distorted square pyramidal geometry. They coordinate to both the pyridyl and carboxylate functionalities of the pyridinecarboxylate bridging ligands. Infinite copper oxide chains run through the structure and are connected by p-pyridinecarboxylate (p-PyC) ligands. Crystal data: monoclinic, space group P21/n, a = 3.5521(2) Å, b = 15.8665(11) Å, c = 12.9977(9) Å, β = 95.285(2)°, and Z = 4. Thermogravimetric analysis (TGA) revealed that the guest H2O molecules in the channels may be removed, and the material is stable to ca. 245 °C. Magnetic measurements indicated the material has one-dimensional (1D) antiferromagnetic ordering within the Cu2+ chains with a Néel temperature of ca. 51 K. Data fitting to the Bonner-Fisher model yielded a coupling constant, J, of -7.3 cm-1 and g factor of 2.15. The Curie tail below 20 K is due to a small amount of paramagnetic impurities, calculated to be ∼0.2% in concentration. Further characterization of crystallinity and morphology are discussed, including powder X-ray diffraction (PXRD), elemental analysis, and optical microscopy. [ABSTRACT FROM AUTHOR]

We report the solvothermal synthesis and characterization of a series of layered lead phenylphosphonates. The crystals were suitable for single crystal X-ray diffraction data, and the two new structures we denote BING-6 [SUNY at Binghamton, Structure No. 6, Pb(PO[sub 3]C[sub 6]H[sub 5])·0.25C[sub 5]H[sub 5]N, triclinic space group P&1oline;, Z = 2, a = 7.0770(4) Å, b = 9.3113(6) Å, c = 14.6785(9) Å, α = 80.456(1)°, β = 78.023(1)°, γ = 73.265(1)°] and BING-9 [Pb(PO[sub 3]-HC[sub 6]H[sub 5])(PO[sub 3]HC[sub 6]H[sub 4]CH[sub 3]), monoclinic space group C2/c, Z = 4, a = 32.663(8) Å b = 5.6220(13) Å, c = 8.3307(19) Å, β = 101.419(4)°]. The third structure, a polytype of BING-9, was previously known only from powder X-ray diffraction methods and is denoted 3 [Pb(PO[sub 3]HC[sub 6]H[sub 5])[sub 2], monoclinic space group C2/c, Z = 4, a = 31.681(6) Å, b = 5.5639(11) Å, c = 8.2515(16) Å, β = 101.814(4)°]. All three structures possess Pb(II) and P centres connected by doubly and triply bridging oxygens. The phenyl groups cap and separate the charge-neutral layers. The phosphonates of BING-6 are nonprotonated, and the structure therefore has a Pb/P ratio of 1:1. Neutral, partially disordered pyridine solvent molecules also reside in the interlamellar space, increasing the layer to layer distance. BING-9 and 3 are polytypes and contain singly protonated phosphonates, for a Pb/P ratio of 1:2. Further characterization methods are discussed, including powder X-ray diffraction, in-situ variable temperature powder X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. Related work in the Ge, Sn, and Mn systems is also discussed. These low-dimensional materials may be useful intercalation compounds for ion-exchange or sensors applications. [ABSTRACT FROM AUTHOR]

Focuses on the development of Pb[sub 3]F[sub 5]NO[sub 3], a cationic layered material for anion-exchange. Structures of layered material; Factors affecting the stability of material temperature; Growth of anionic clusters within the void space of cationic material.

Examines the photophysical and photochemical properties of W(O) and Re(I) carbonyl complexes. Use of special redox-active features to develop electrochemical sensors; Focus on homonuclear ferrocenes different organic spacers; Photophysical and photochemical properties of polypyridyl d[sup 6]-metal(W[sup 0] and Re[sup I]) carbonyl complexes.

Hierarchical two-dimensional (2D) lamellar zeolites represent a young emerging field and a novel expression of the zeolite frameworks. Accompanied with synthesis and catalytic performance investigation, assessment on the local environment and catalytic behavior of acid sites in 2D zeolites are needed. Here, we described the local environment of Lewis acid sites and evaluated catalytic activities of external acid sites (i.e. sites on external surface and in mesopores) in 2D lamellar titanium silicalite-1 (TS-1) zeolites. For comparison purpose, four TS-1 zeolites, including 3D TS-1, multilamellar 2D TS-1 without pillarization and with pillarization by silica and silica/titania, respectively, were prepared. The local environment of Ti-sites, including coordination status of Ti-atom, speciation of hydroxyl (-OH) group that hints degree of confinement, acid site strength and accessibility, was collectively assessed by spectroscopic and organic base titration measurements. Kinetic studies of cyclooctene (C 8 H 14) epoxidation with hydrogen peroxide (H 2 O 2) discerned catalytic activity of external Ti-sites that decreased with increasing mesoporosity due to decrease in site confinement. Image 1 • External Lewis acid sites in 2D TS-1 zeolites were quantified. • 2D TS-1 zeolites have high density of isolated surface silanol and titanol groups. • Reactivity of external sites decreases with increasing mesoporosity in 2D TS-1. • Decrease in reactivity of external sites is caused by loss of partial confinement. • Kinetic decoupling of epoxidation pathways enabled catalytic behavior assessment. [ABSTRACT FROM AUTHOR]

Objective: We calculated the short- and long-term care resource use and costs in adults with high-risk conditions for cardiovascular disease (HRCVD) as defined by the Canadian Cardiovascular Society dyslipidemia guidelines.We linked Alberta health databases to identify patients aged ≥ 18 years with HRCVD between fiscal year (FY) 2012 and FY2016. The first HRCVD event was the index event. Patients were categorized into (1) primary prevention patients and (2) secondary prevention patients at the index event and were followed until death, they moved out of the province, or they were censored at March 2018. We calculated the resource use and costs for each of the 5 years after the index event.The study included 459,739 HRCVD patients (13,947 [3%] were secondary prevention patients). The secondary prevention patients were older (median age 61 years vs. 55 years; p < 0.001), and there were fewer females in this group (30.4% vs. 51.3%; p < 0.001). The total healthcare costs in the first year decreased over time (FY2012: 1.16 billion Canadian dollars (CA$); FY2016: CA$1.05 billion; p < 0.001). An HRCVD patient incurred CA$12,068, CA$5626, and CA$4655 during the first, second, and fifth year, respectively (p for trend < 0.001). During the first year, healthcare costs per secondary prevention patient (CA$36,641) were triple that for a primary prevention patient (CA$11,299; p < 0.001), primarily due to higher hospitalization costs in secondary prevention patients (CA$26,896 vs. CA$6051; p < 0.001).The healthcare costs for HRCVD patients were substantial but decreased over time. The costs were highest in the year following the index event and decreased thereafter. Secondary prevention patients incurred higher costs than the primary prevention patients.Methods: We calculated the short- and long-term care resource use and costs in adults with high-risk conditions for cardiovascular disease (HRCVD) as defined by the Canadian Cardiovascular Society dyslipidemia guidelines.We linked Alberta health databases to identify patients aged ≥ 18 years with HRCVD between fiscal year (FY) 2012 and FY2016. The first HRCVD event was the index event. Patients were categorized into (1) primary prevention patients and (2) secondary prevention patients at the index event and were followed until death, they moved out of the province, or they were censored at March 2018. We calculated the resource use and costs for each of the 5 years after the index event.The study included 459,739 HRCVD patients (13,947 [3%] were secondary prevention patients). The secondary prevention patients were older (median age 61 years vs. 55 years; p < 0.001), and there were fewer females in this group (30.4% vs. 51.3%; p < 0.001). The total healthcare costs in the first year decreased over time (FY2012: 1.16 billion Canadian dollars (CA$); FY2016: CA$1.05 billion; p < 0.001). An HRCVD patient incurred CA$12,068, CA$5626, and CA$4655 during the first, second, and fifth year, respectively (p for trend < 0.001). During the first year, healthcare costs per secondary prevention patient (CA$36,641) were triple that for a primary prevention patient (CA$11,299; p < 0.001), primarily due to higher hospitalization costs in secondary prevention patients (CA$26,896 vs. CA$6051; p < 0.001).The healthcare costs for HRCVD patients were substantial but decreased over time. The costs were highest in the year following the index event and decreased thereafter. Secondary prevention patients incurred higher costs than the primary prevention patients.Results: We calculated the short- and long-term care resource use and costs in adults with high-risk conditions for cardiovascular disease (HRCVD) as defined by the Canadian Cardiovascular Society dyslipidemia guidelines.We linked Alberta health databases to identify patients aged ≥ 18 years with HRCVD between fiscal year (FY) 2012 and FY2016. The first HRCVD event was the index event. Patients were categorized into (1) primary prevention patients and (2) secondary prevention patients at the index event and were followed until death, they moved out of the province, or they were censored at March 2018. We calculated the resource use and costs for each of the 5 years after the index event.The study included 459,739 HRCVD patients (13,947 [3%] were secondary prevention patients). The secondary prevention patients were older (median age 61 years vs. 55 years; p < 0.001), and there were fewer females in this group (30.4% vs. 51.3%; p < 0.001). The total healthcare costs in the first year decreased over time (FY2012: 1.16 billion Canadian dollars (CA$); FY2016: CA$1.05 billion; p < 0.001). An HRCVD patient incurred CA$12,068, CA$5626, and CA$4655 during the first, second, and fifth year, respectively (p for trend < 0.001). During the first year, healthcare costs per secondary prevention patient (CA$36,641) were triple that for a primary prevention patient (CA$11,299; p < 0.001), primarily due to higher hospitalization costs in secondary prevention patients (CA$26,896 vs. CA$6051; p < 0.001).The healthcare costs for HRCVD patients were substantial but decreased over time. The costs were highest in the year following the index event and decreased thereafter. Secondary prevention patients incurred higher costs than the primary prevention patients.Conclusions: We calculated the short- and long-term care resource use and costs in adults with high-risk conditions for cardiovascular disease (HRCVD) as defined by the Canadian Cardiovascular Society dyslipidemia guidelines.We linked Alberta health databases to identify patients aged ≥ 18 years with HRCVD between fiscal year (FY) 2012 and FY2016. The first HRCVD event was the index event. Patients were categorized into (1) primary prevention patients and (2) secondary prevention patients at the index event and were followed until death, they moved out of the province, or they were censored at March 2018. We calculated the resource use and costs for each of the 5 years after the index event.The study included 459,739 HRCVD patients (13,947 [3%] were secondary prevention patients). The secondary prevention patients were older (median age 61 years vs. 55 years; p < 0.001), and there were fewer females in this group (30.4% vs. 51.3%; p < 0.001). The total healthcare costs in the first year decreased over time (FY2012: 1.16 billion Canadian dollars (CA$); FY2016: CA$1.05 billion; p < 0.001). An HRCVD patient incurred CA$12,068, CA$5626, and CA$4655 during the first, second, and fifth year, respectively (p for trend < 0.001). During the first year, healthcare costs per secondary prevention patient (CA$36,641) were triple that for a primary prevention patient (CA$11,299; p < 0.001), primarily due to higher hospitalization costs in secondary prevention patients (CA$26,896 vs. CA$6051; p < 0.001).The healthcare costs for HRCVD patients were substantial but decreased over time. The costs were highest in the year following the index event and decreased thereafter. Secondary prevention patients incurred higher costs than the primary prevention patients. [ABSTRACT FROM AUTHOR]

Lead substituted hydroxyapatite (Pb-HAP) has been an active catalyst for oxidative coupling of methane (OCM) reactions. CO 3 2 − substituted HAP (HAP-CO 3 ) has showed enhanced oxide ion conductivity than bare HAP in high temperature solid oxide fuel cells. Substitutions for both cations and anions in HAP structure (Pb-HAP-CO 3 ) are promising to integrate the catalytic property of Pb-HAP and oxide ion conductive property of HAP-CO 3 into one apatite-based ceramic material that can be manufactured into membrane reactors for possessing CH 4 activation and O 2 permeation capabilities for efficient OCM reactions. In this work, the effects of substitutions for both cation (Pb 2+ ) and anion (CO 3 2 − ) in HAP structure on OCM reactions were studied. The composition and physicochemical properties of HAP catalysts were changed by the cation and anion substitutions, respectively, and as consequences, they influenced the catalytic performances of HAP structure in OCM reactions. The selectivity to C 2 (ethylene and ethane) products increased in the order of HAP-CO 3 < HAP < Pb-HAP-CO 3 < Pb-HAP, while Pb-HAP-CO 3 showed the best stability and comparable C 2 yield (under optimized reaction conditions) to Pb-HAP catalyst. Under different reaction temperature and/or CH 4 /O 2 ratio in the OCM reactions, the CH 4 conversion and C 2 or CO x (CO and CO 2 ) selectivity showed a strong dependence on the composition of HAP-based catalysts. The present study forms a basis for understanding of the correlations between the composition, structure, and catalytic performance of HAP and other apatite structured catalysts, which are potential membrane materials for OCM reactions in membrane reactors. [ABSTRACT FROM AUTHOR]

Highlights: [•] Ag nanoparticles were incorporated into hydrogel, aerogel and film of NFC. [•] Addition of AgNO3 triggered hydrogelation of NFC. [•] The gelation mechanism of NFC by monovalent cations was explored. [•] The NFC-Ag aerogel had less BET surface area than the NFC aerogel. [•] Presence of Ag species reduced coalescence of NFC in the film formation. [Copyright &y& Elsevier]

Herein we report a method for the synthesis of 2‐aryl thiochromenones via a sulfuration of 2'‐chlorochalcones. The chalcones could be prepared in advance or in situ obtained from 2'‐chloroacetophenones and aromatic aldehydes. The conditions were tolerant of functionalities including chloro, fluoro, methylthio, phenoxy, and trifluoromethyl groups. 2‐Heteroaryl thiochromenones could also be obtained in moderate yields. Our method appears to be a simple, general tactic to afford 2‐aryl thiochromenones from commercial starting materials. [ABSTRACT FROM AUTHOR]

Objective: Our objective was to describe the costs of industry-sponsored clinical trials for medical devices in Northern Alberta, Canada. Methods: We used centralized data to identify all industry-sponsored medical device clinical trials initiated in Northern Alberta from 2012 to 2016. For each arm of each trial, we calculated the price of devices provided by the sponsor and the cost of clinical and administrative services that were incurred to clinically operationalize the treatment. Results: Our sample consisted of 18 device trials initiated between January 2012 and January 2016. The overall cost (Canadian dollars [$Can], year 2018 values) per enrolee was $Can18,243 for the experimental arm and $Can13,827 for the control arm. Devices were the highest cost component, at $Can13,446 per enrollee in the experimental arm. Clinical costs in the control arms were higher on average ($Can7202 vs. 2504) than those in the experimental arms. Conclusion: Data from industry-sponsored clinical trials can provide important information on the full costs of device-related interventions. As device costs rise, and as policy makers require more evidence on device-related treatments, the cost of medical device-driven interventions should be documented along with their effectiveness. [ABSTRACT FROM AUTHOR]

• Anchoring nature and spatial distribution of ReO x on zeolite supports were studied. • Effects of zeolite support acidity and mesoporosity on ReO x were examined. • ReO x species anchored predominantly on Brønsted acid sites enclosed in micropores. • Decrease in acidity transited the anchoring of ReO x onto silanol (Si-OH) groups. • Increase in mesoporosity migrated ReO x onto external acid sites and Si-OH groups. The anchoring nature and spatial distribution of rhenium oxide (ReO x) supported on zeolites (ReO x /zeolite) were determined as a function of the support acidity and mesoporosity. The ReO x /zeolite samples were characterized collectively using Argon isotherm, XRD, Raman, XAS, DRIFTS, and organic chemical titrations. The results show that the ReO x species formed the isolated distorted tetrahedral ReO 4 − structure. On the zeolite support, ReO x species anchored predominantly on Brønsted acid sites (Si-OH+-Al) enclosed in micropores (internal acid sites), by replacing the protons in Si-OH+-Al sites at a H+/Re ratio of ∼1.1 in zeolites with high acidity. The decrease in zeolite acidity led to the anchoring of ReO x species onto both Si-OH+-Al and silanol group (Si-OH). The increase in zeolite mesoporosity migrated the ReO x species onto both internal acid sites and those on the external surface and mesopores (external acid sites), as well as Si-OH groups. The implication of distribution of ReO x in zeolite was explored by direct non-oxidative methane conversion reaction. [ABSTRACT FROM AUTHOR]

Abstract The pillared MWW (PMWW or MCM-36) and pillared MFI (PMFI) are two prominent representatives of meso-/microporous lamellar zeolites, which are made by pillaring of layered MCM-22(P) and multilamellar MFI precursors, respectively. They both consist of a 10-membered ring sinusoidal micropore channel within each zeolitic layer and mesopore voids created by pillars between two adjacent zeolitic layers. Although catalytic activities of PMWW and PMFI have been compared, identification of mesopore differences between these two pillared lamellar zeolites has not been attempted. In this work, we report the differences in mesopore characteristics between PMWW and PMFI zeolites probed by atomic layer deposition (ALD) of titania (ALD-TiO 2) species and a combination of structural, textural, composition and catalytic property analyses of the samples before and after ALD treatment, respectively. The results suggest PMFI has cylindrical mesopores with uniform sizes from pore entrance to main body, while PMWW has ink-bottle mesopores with the neck size much smaller than pore body. The communication between micropore and mesopore in PMFI is direct, but no communication exists in PMWW zeolites. The ALD-TiO 2 process considerably modified external surface composition of PMFI and PMWW zeolites, which consequently led to a new application of the pillared lamellar zeolite materials, i.e., photo-catalytically active meso-/microporous zeolites for environmental remedy reactions. Graphical abstract Image 1 Highlights • Identification of mesopore differences between PMFI and PMWW was attempted. • Atomic layer deposition of titania was used as probe for mesopore differences. • PMFI has more uniform mesopores compared to PMWW zeolite. • Atomic layer deposition of titania enabled photocatalytic activity. [ABSTRACT FROM AUTHOR]

Direct non-oxidative methane coupling (NMC) is one of the promising pathways for methane upgrading into value-added olefin and aromatic hydrocarbons. The silica-supported iron (i.e., Fe/SiO 2) catalyst has been reported effective for NMC, but the effects of silica support on the catalyst property and NMC performance have rarely been explored. In this work, we prepared a vitreous silica-supported iron (Fe/SiO 2 -V) catalyst by flame fusion of a mixture of quartz silica and fayalite. The physicochemical properties and NMC performance of the as-prepared catalysts were measured. Compared to crystalline cristobalite support in Fe/SiO 2 catalyst that has been studied previously, vitreous silica support has disordered Si-O bonds and structural defects, enabling better iron dispersion and more vital metal-support interaction. The as-prepared Fe/SiO 2 -V catalyst had a shorter induction period in methane activation and lower coke yield in NMC. The increase in iron concentration in Fe/SiO 2 -V catalysts elongated the catalyst induction period and promoted aromatics and coke formation. The coke type of the spent Fe/SiO 2 -V catalyst is more uniform than the cristobalite-supported iron catalyst. [Display omitted] • Vitreous silica-supported iron catalysts were prepared by an oxyhydrogen flame fusion method. • The amorphous vitreous silica support contains disordered and defective Si-O bonds. • Iron has higher dispersion and more uniform bonding in the vitreous silica support. • Vitreous silica-supported iron enabled fast methane activation and low coking in NMC. • Increase in iron loading in vitreous silica support promoted aromatics formation. [ABSTRACT FROM AUTHOR]

The combination of two compositionally and/or structurally different zeolites into one single zeolite composite particle is a potential approach to integrate advantages of different zeolite structures for desirable properties and applications. In the present study, we report the overgrowth of lamellar mesoporous silicalite-1 on the commercial microporous MFI and BEA zeolites, respectively, to render hierarchical meso-/microporous lamellar silicalite-1/MFI (L-Si/MFI) and lamellar silicalite-1/BEA (L-Si/BEA) zeolite composites via hydrothermal crystallization of lamellar silicalite-1 with the assistance of a diquaternary ammonium template. Epitaxial growth of lamellar silicalite-1 on commercial bulk MFI was observed, resulting in the L-Si/MFI zeolite composite as porcupine sensory message ball with nerve-stimulating silicalite-1 bumps extended from the MFI particle. In the L-Si/BEA zeolite composite, the lamellar silicalite-1 was laid over the surface of or partially interdigitated into the commercial bulk BEA particle, forming a BEA nanosponge structure connected to lamellar silicalite-1 nanosheets. The resultant interconnected micro- and mesoporosity in the L-Si/MFI and L-Si/BEA composite zeolites allowed facile mass transport of bulky molecules. The acid sites sitting on the external surface of commercial MFI and BEA zeolites were partially passivated by the lamellar silicalite-1. The consequences of improved mass transport and passivation of external acid sites on the catalytic performance of these zeolite composites were tested in 2 wt% molybdenum (Mo) loaded L-Si/MFI and L-Si/BEA for direct non-oxidative methane aromatization reaction, which showed higher methane conversion and hydrocarbon product formation as well as higher selectivity to naphthalene and coke in comparison with 2 wt% Mo-loaded commercial MFI and BEA catalysts. [ABSTRACT FROM AUTHOR]

On the path toward the design of Li-ion batteries with increased energy densities, efforts are focused on the development of positive electrodes that can maximize the voltage of the full cell. However, the development of novel materials that operate at high voltage, while also showing high efficiency and meeting strict safety standards, is an ongoing challenge. LiCoPO4 is being explored as a possible candidate, as the Co2+/3+ redox couple operates at 4.8 V versus Li+/Li0. The presence of phosphate groups is typically expected to stabilize the compound against oxygen loss, yet the changes in Co-O bonding upon Li extraction have not been ascertained. In addition, LiCoPO4 is riddled with problems relating to poor transport and strain in the crystal structure of the delithiated phase, which handicap its use as a high-voltage electrode. In this work, substituting ions to generate Li1.025Co0.84Fe0.10Cr0.05Si0.01(PO4)1.025 is found to stabilize both the electronic structure and crystal structure and, therefore, substantially improve the ability to fully utilize the redox capacity of the material. A thorough study by spectroscopic tools, combined with computations of the electronic structure, was used to probe changes in chemical bonding. The measurements revealed the existence of redox gradients between surface and bulk that are common in other materials that react at high potential. The study offers a comprehensive understanding of the fundamental reactions in LiCoPO4-type frameworks, while further demonstrating that ion substitution is an effective tool for improving their performance. [ABSTRACT FROM AUTHOR]

Lamellar MFI zeolite and lamellar MFI zeolite supported nickel were synthesized and examined for ex-situ catalytic upgrading of the vapors (without using any fluidized gases such as N 2 and H 2) resulted from fast pyrolysis of wood chips in comparison to its commercial MFI zeolite and its supported nickel counterparts. Pyrolysis tests were carried out using a catalytic augur reactor at atmospheric pressure, while pyrolysis unit was operating at 450 °C and upgrading unit at 420 °C, respectively. The introduction of nickel with a high dispersion over the zeolitic supports caused a significant increase in the products of aromatic compounds. Moreover, the addition of nickel to zeolite supports changed their acidity and decreased the total number of acid sites and the ratio of Brønsted to Lewis acid sites as determined by pyridine-FTIR spectroscopy. The use of lamellar zeolite catalysts increased the efficiency of catalytic cracking of pyrolysis vapors and their modification with nickel helped tuning the Lewis acidity to further increase catalytic cracking which resulted in a higher yield of the low molecular weight aromatics present in the bio-oil. • Lamellar catalysts are synthesized and extensively characterized. • Ex-situ catalytic fast pyrolysis without fluidizing gas can lead to a low bio-oil deoxygenation. • Lamellar catalysts are found to enhance catalytic cracking of pyrolysis oil vapors. • Lamellar catalysts show no loss in activity after multiple uses. [ABSTRACT FROM AUTHOR]

The pillared MWW (PMWW or MCM-36) and pillared MFI (PMFI) zeolites are 2-dimensional (2D) catalytically active materials made by pillaring of layered MCM-22(P) and multilamellar MFI precursors, respectively. The single- or near single-unit-cell thick 2D microporous layers in PMWW and PMFI expose comparable number of external surface acid sites ( i.e. , acid sites enclosed in mesopores between zeolitic layers) to those in micropores, which become important or dominant contributor to the catalytic properties. Although the acidity and catalytic activities of PMWW and PMFI have been studied, modification of their external surfaces and its implications on catalytic reactions are not available. In the present study, we report the tailoring of external surfaces of PMWW and PMFI zeolites by atomic layer deposition (ALD) of silicon (ALD-Si) and aluminum (ALD-Al), respectively. The textural, acidic and catalytic properties of the ALD modified pillared zeolites were investigated using a variety of characterization methods. ALD-Al and ALD-Si modifications kept micropore almost intact, but resulted in significant reduction in mesopore volume and considerable changes in external surface composition and acidity. The catalytic tests showed that intrinsic catalytic behavior of Brønsted acid sites in ALD modified pillared zeolites was similar to their parent counterparts. In diffusion constrained parallel reactions, ALD of Al- or Si-species altered catalyst selectivity. In addition, ALD of Si-species on PMFI zeolite deactivated surface active sites, which resulted in improved catalytic activity in direct methane aromatization reactions under optimal ALD cycles. The study exemplified for the first time that ALD is an effective tool for tuning the surface properties of 2D unit-cell thick zeolites. [ABSTRACT FROM AUTHOR]

Our research group previously reported a two-dimensional cationic inorganic material (BING-5, Pb3F5NO3) where nitrate resides in the interlamellar space and can be anion exchanged. Investigation of the possible exchange of nitrate for benzoate led to the discovery of a layered metal–organic framework, lead benzoate hydrate [Pb(C6H5CO2)2(OH2)]. The compound crystallizes as colourless plates in the monoclinic space group P21/c. The two dimensional lead–oxygen layers contain bridging benzoate oxygen atoms, with bridging water molecules further supporting the layers. The benzoate molecules are positioned perpendicular to the layers and form a hydrophobic bilayer region. The material shows basic character when immersed in various solvents suggesting potential as a base catalyst. [ABSTRACT FROM AUTHOR]

Spinel-structured solids were studied to understand if fast Li+ ion conduction can be achieved with Li occupying multiple crystallographic sites of the structure to form a "Li-stuffed" spinel, and if the concept is applicable to prepare a high mixed electronic-ionic conductive, electrochemically active solid solution of the Li+ stuffed spinel with spinel-structured Li-ion battery electrodes. This could enable a single-phase fully solid electrode eliminating multi-phase interface incompatibility and impedance commonly observed in multi-phase solid electrolyte–cathode composites. Materials of composition Li1.25M(III)0.25TiO4, M(III) = Cr or Al were prepared through solid-state methods. The room-temperature bulk Li+-ion conductivity is 1.63 × 10−4 S cm−1 for the composition Li1.25Cr0.25Ti1.5O4. Addition of Li3BO3 (LBO) increases ionic and electronic conductivity reaching a bulk Li+ ion conductivity averaging 6.8 × 10−4 S cm−1, a total Li-ion conductivity averaging 4.2 × 10−4 S cm−1, and electronic conductivity averaging 3.8 × 10−4 S cm−1 for the composition Li1.25Cr0.25Ti1.5O4 with 1 wt. % LBO. An electrochemically active solid solution of Li1.25Cr0.25Mn1.5O4 and LiNi0.5Mn1.5O4 was prepared. This work proves that Li-stuffed spinels can achieve fast Li-ion conduction and that the concept is potentially useful to enable a single-phase fully solid electrode without interphase impedance. [ABSTRACT FROM AUTHOR]

• Characteristics of the coke deposits on lamellar metal (Ga or Zn)-modified zeolites were studied. • Mesoporous lamellar structure decreases the coke formation by facilitating the external coke deposition. • Metal modification decreases the coke formation by changing the acidity of zeolite. • Highest fraction of light coke is obtained for Zn-modified lamellar zeolite. • Both zeolite structure and metal-modified acidity affect the coke formation. The effects of meso-/microporous structure and metal-additive (Ga or Zn) of lamellar MFI catalysts on the characteristics of coke deposits during ethylene-to-aromatic liquids conversion were investigated. The nature, composition, and location of coke deposits in spent lamellar catalysts were analyzed and compared to those on the microporous MFI counterparts, using FTIR, UV–Vis, GC–MS, and argon adsorption-desorption. The total amount of coke and the changes in coke nature during catalyst regeneration were studied by MS/FTIR combined with temperature programmed oxidation. The lamellar meso-/microporous structure of MFI reduces the coke quantity and the heavy coke fractions. The coke preferentially deposites on external surface of lamellar zeolite due to the lower diffusion limitation for bulky coke precursors. Metal-additive changes the catalyst acidity and decreases the coke formation rate, especially when zinc is used. Therefore, the coke formation on zeolite can be tuned by modulating the textural and acidity properties of the metal-modified catalyst. [ABSTRACT FROM AUTHOR]

• Catalytic performance of metal (Ga or Zn)-loaded mesoporous lamellar zeolites was evaluated. • Mesoporous lamellar structure is pivotal in determining metal dispersion in zeolite catalyst. • Metal loading changes the acidity of the zeolite catalyst and effect of Zn is more pronounced compared to Ga. • Higher liquid aromatics yield and selectivity for mono-benzene alkylated aromatics was observed while less coke was formed. • Both zeolite structure (mesoporosity) and type of metal dopant affect the catalytic performance of catalyst. The effects of meso-/microporous structure and metal-modification with gallium or zinc on catalytic performances of lamellar MFI zeolites in ethylene conversion reaction to liquid aromatics were investigated. TEM, XRD, Ar adsorption-desorption, UV-Visible spectroscopy, and H 2 -TPR measurements showed that the zeolite structure is a pivotal factor for controlling the type of metal dopant species forming on zeolite, their size, and their distribution. Adding metal dopants to zeolite structure decreased the Brønsted to Lewis (B/L) acid site ratio in the zeolites and improved their catalytic performance. As a result, metal-modified lamellar MFI zeolites showed higher liquid aromatics yield and selectivity for mono-benzene alkylated aromatics and lower coke formation rate compared to their microporous commercial MFI analogies. Zinc-loaded lamellar MFI had the most efficient catalytic performance among all studied catalysts. This phenomenon can be explained by higher accessibility of reactants to active sites and facilitated transport of products from lamellar structure of this zeolite and the low B/L acid site ratio of this catalyst provided by metal-modification, which is more suitable for ethylene aromatization. A bifunctional reaction mechanism has been proposed based on the analysis results of reaction product distributions that demonstrates the effect of both zeolite acid sites and metal sites in conversion of ethylene to liquid aromatics over MFI zeolite catalysts. [ABSTRACT FROM AUTHOR]