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A new palladium‐based catalyst system modified with dibenzofuran (DBF) was developed for acetylene hydrochlorination. The optimal Pd‐DBF/SAC catalyst with the 0.5 wt% Pd loading and the 15 wt% DBF loading exhibits an elevated performance of 99.9% acetylene conversion and 99.9% vinyl chloride selectivity for more than 400 h. Characterization analysis and density functional theory (DFT) simulations revealed that the presence of oxygen‐containing DBF species of the Pd‐DBF/SAC catalyst prevents the reduction and loss of Pd species, inhibits the carbon deposition and enhances the HCl adsorbability, resulting in superior catalytic activity and stability for acetylene hydrochlorination. [ABSTRACT FROM AUTHOR]

Easily soluble organic components in Santanghu long flame coal (SLFC) from Hami (Xinjiang, China) were separated by CS2 and acetone mixed solvent (v/v = 1:1) under ultrasonic condition, and the extract residue was stratified by carbon tetrachloride to obtain the light raffinate component (SLFC-L). The effect of solvent treatment on the composition and structure of the coal and its rapid pyrolysis products was analyzed. Solvent treatment can reduce the moisture content in coal from 9.48% to 6.45% and increase the volatile matter from 26.59% to 28.78%, while the macromolecular structure of the coal changed slightly, demonstrating the stability of coal's complex organic structure. Compared with raw coal, the relative contents of oxygen-containing functional groups and aromatic groups in SLFC-L are higher, and the weight loss rates of both SLFC and SLFC-L reached the maximum at about 450 °C. In contrast, the loss rate of SLFC-L is more obvious, being 33.62% higher than that of SLFC. Pyrolysis products from SLFC at 450 °C by Py-GC/MS are mainly aliphatic hydrocarbons and oxygenated compounds, and the relative contents of aliphatic hydrocarbons decreased from 48.48% to 36.13%, while the contents of oxygenates increased from 39.07% to 44.95%. Overall, the composition and functional group in the coal sample were changed after solvent treatment, resulting in a difference in the composition and distribution of its pyrolysis products. [ABSTRACT FROM AUTHOR]

A novel supported bismuth (Bi)-based catalyst was prepared using halloysite nanotubes (HNTs) as a carrier and effectively used for acetylene hydrochlorination. The proposed Bi/HNT catalyst exhibited potential catalytic performance. The loss of active species (Bi species) and the accumulation of carbon deposition on the surface are the main reasons for the Bi/HNT catalyst's deactivation. [ABSTRACT FROM AUTHOR]

BACKGROUND Advanced oxidation processes based on sulfate radical have been widely employed for oxidation degradation of organic contaminants. Catalytic activation of peroxymonopersulfate (PMS) with transition metal oxides holds great promise for the generation of sulfate radical. In this work, laponite‐decorated CoFe2O4 porous nanostructures have been prepared through the thermal decomposition of laponite/oxalates, and evaluated as a magnetic catalyst to activate PMS for the oxidation of rhodamine B (RhB). RESULTS: The decoration of porous CoFe2O4 microparticles with laponite was evidenced because of the presence of the vibration mode of SiO (at 1359 cm−1) in Fourier transform infrared spectra and the uniform distribution of Si and Mg elements from elemental mapping images. Decorating with laponite also resulted in an increase in amount of surface hydroxyl oxygen species, which facilitated the formation of CoOH complex for PMS activation. Furthermore, the enhanced activation of PMS with laponite‐decorated CoFe2O4 resulted in a faster removal (98.04%) of RhB as compared to undecorated CoFe2O4 (79.62%) within 56 min. Meanwhile, the rate constant increased from 0.0288 (CoFe2O4) to 0.0679 min−1 (laponite‐decorated CoFe2O4). The degradation rate of RhB progressively increased with reaction temperature and catalyst dosage. Scavenging and electron paramagnetic resonance tests manifested that the sulfate and superoxide radicals served as the major active species for the oxidation of RhB molecules. CONCLUSION: The above results demonstrated positive effects of laponite on the textural property, surface chemical states and catalytic activity of porous CoFe2O4 microparticles. This study provides an insight into the promising role of laponite as an additive in improving PMS activation. [ABSTRACT FROM AUTHOR]

BACKGROUND 4‐Nitrophenol, as a representative hazardous contaminant, may pose potential risks to the environment in the process of production, storage, and use. Catalytic hydrogenation reduction offers a promising route to the removal of 4‐nitrophenol by its transformation into the less toxic and biodegradable 4‐aminophenol. In this work, nickel−cobalt bimetal oxide nanostructures were fabricated by the thermal decomposition of metal organic frameworks and cooperatively utilized for the catalytic reduction of 4‐nitrophenol. RESULTS: The as‐fabricated oxide catalysts were characterized and analyzed with several physicochemical measurements, including X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy, thermogravimetry, Fourier‐transform infrared spectroscopy, Raman spectroscopy, nitrogen adsorption, and electrochemical impedance spectroscopy. The catalytic reduction of 4‐nitrophenol was conducted in the presence of the as‐prepared oxide nanostructures with varying Ni/Co ratios to evaluate their catalytic activity. The optimal catalyst (Ni–Co–O) delivered the activity parameter of k'app = 12.0 min−1 mg−1, which was higher than either NiO (2.4 min−1 mg−1) or Co3O4 (3.6 min−1 mg−1). Moreover, the induction time of the 4‐nitrophenol reduction was significantly reduced by using the bimetal oxide catalyst. Based on the surface and electrochemistry analyses, the enhancement of catalytic activity for the Ni–Co bimetal oxide nanostructures was discussed. CONCLUSION: The above results indicated that the cooperation of nickel with cobalt into bimetal oxide nanostructures exhibited an enhanced catalytic activity, which not only promoted the conversion rate of 4‐nitrophenol, but also shortened the reduction induction period. [ABSTRACT FROM AUTHOR]

Abstract: A facile molten salt method was utilized for the synthesis of carbon anchored nickel/heazlewoodite nanoparticles (Ni/Ni3S2@C nanosheets) with potassium humate as the carbon and sulfur source and NaCl as template. The morphology, particle size and crystallinity of the products were characterized by various techniques containing TEM, FE‐SEM and XRD. Furthermore, the mesoporous Ni/Ni3S2@C own easy accessibility of active sites and high surface area (149.04 m2 g−1). Thus, the as‐prepared Ni/Ni3S2@C exhibited prominent performance for catalytic reduction of 4‐nitrophenol (4‐NP). Catalytic reduction of other nitrophenols (NPs) were also tested which can prove that the catalyst own selectivity on reduction of NPs. For durability, the property of the catalyst does not decrease obviously after five cycles. More significant correlations concerning effect of activation parameters (Ea=37.21 kJ mol−1) on 4‐NP reduction were scrutinized and discussed. Hence, we provide a facile method for fabrication of metal/metal sulfide@C which own better dispersity, small dimension and excellent catalytic performance for further studies. [ABSTRACT FROM AUTHOR]

The PbVOF crystal was synthesized by hydrothermal method. The crystal structure consists of tetranuclear [PbOF] and twinborn VOF units, which share the O and F atoms forming a three-dimensional framework. The birefringence of the compound was investigated using the first principles. The calculations results show that the compound has a large birefringence of 0.336 at 1064 nm. Researches indicate that its large birefringence originates mainly from the distorted VOF groups based on the real-space atom-cutting method and structure-property relationships analysis. Furthermore, the IR spectrum, thermal behaviors, and UV-Vis-IR diffuse reflectance spectroscopy of the compound are also presented. [ABSTRACT FROM AUTHOR]

ABSTRACT Thermo-induced multishape memory polymers are a growing focus of smart materials because of its promising applications. Multishape memory effect is generally attained by using polymers with broad phase transition and multiphase polymers. The latter is of particular interest for copolymerization and polymer compositing. One requirement has to be fulfilled to achieve multishape memory effect, which is to have two reversible phase transitions. In this study, we report synthesis of polymer composite composed of strong segregated polymers by using reaction-induced phase separation. We demonstrate the method by using polyurethane (PU) and poly(methacrylic acid) (PMAA). With adjusting the weight ratio, the polymer composites exhibit a phase spectrum from phase separation to miscible composite. The composite with PU/PMAA =3:1 demonstrated triple-shape memory effect. Based on the results, we argued the effect of segregation on the shape memory effect for polymer composites. With the addition of PMAA, the polymer composite also exhibits pH/water-induced shape memory effect. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43534. [ABSTRACT FROM AUTHOR]

In this work, we evaluated the effect of crosslinking concentration on the affinity of poly (2-acrylamido-2-methyl-1-propansulfonic acid) (PAMPS) hydrogel-supported Fe3O4 nanozyme towards substrates (tetramethylbenzidine (TMB) and H2O2). The peroxidase-like catalytic activity of PAMPS/Fe3O4 nanozyme was discussed with respect to crosslinking concentration of PAMPS hydrogel for the oxidation of TMB in the presence of H2O2 at room temperature. High catalytic activity was achieved due to good dispersion of Fe3O4 nanozyme in the hydrogel network and strong affinity of PAMPS hydrogel-supported Fe3O4 nanozyme towards substrates. The affinity between the hydrogel-supported Fe3O4 nanozyme and substrates can be improved by regulating the crosslinking concentration of PAMPS hydrogel without other trenchant experimental conditions. In addition, the result indicated that H2O2 can be detected even at a concentration as low as 1.5 × 10–6 mol L–1 with a linear detection range of 1.5–9.8 – 10–6 mol L–1. Such investigations not only showed a new approach to improve the affinity and peroxidase-like activity of Fe3O4 nanozyme, but also verified its potential application in bio-detection and environmental chemistry. [ABSTRACT FROM AUTHOR]

ABSTRACT We report a study on the synthesis of anatase titania (TiO2) particles with the sol-gel method at room temperature. We immobilized the particles on a grafted-cellulose intercalated montmorillonite (MMT). This nanocomposite, cellulose- g-poly(4-vinyl pyridine)/MMT/TiO2, could be applied in the photocatalytic degradation of organic pollutants efficiently because of the addition of a sorbent, the grafted cellulose. The synthesized nanocomposite was characterized with Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Methyl orange was used as a model molecule to study photocatalytic degradation. The nanocomposite exhibited a better photocatalytic activity than in the absence of the grafted cellulose. The kinetics of the photocatalytic degradation could be described by pseudo-first-order rate law. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42627. [ABSTRACT FROM AUTHOR]