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• The Si-O-Cs groups are identified as active sites. • The promotion of Brønsted acid sites in Cs dispersion was revealed. • The maximum MA production reaches up to 7.23 mmol·g Cat −1·h−1. • The deactivation behavior of catalyst was demonstrated. With the gradual depletion of petroleum resources and overcapacity of coal industry, the one-step synthesis of methyl acrylate (MA) from the coal-based methyl acetate (Ma) and formaldehyde via aldol condensation, regarded as a supplementary route for the petroleum-based propene selective oxidation, receives significant attention in decades. Herein, a series of Cs/Beta zeolite catalysts were developed for this transformative process using incipient wetness impregnation with varied Cs loading amount and SiO 2 /Al 2 O 3 ratio. The physicochemical properties of both prepared Cs/Beta zeolite catalyst series and Beta zeolite supports were characterized by using FT-IR, ICP, XRF, physical N 2 adsorption–desorption isotherms, NH 3 -TPD, Py-IR, 31P-MAS NMR, XRD and XPS, in combination with catalytic evaluation experiments. The effects of Brønsted acid sites, SiO 2 /Al 2 O 3 ratio and Cs loading on the catalytic performance and catalyst deactivation were systematically investigated. The Brønsted acid sites on Beta zeolite support showed promotional effects on the dispersion of loaded Cs species and formation of (Al-O)-Si-O-Cs groups which were crucial to the improvement of catalytic activity and selectivity. However, the excessive Brønsted acid sites on Cs/Beta or Beta zeolite would lead to the heavy side reactions, including the hydrolysis of Ma and dehydration and further aromatization of methanol (MeOH). As a result, the highest formation rate of 7.23 mmol·g Cat −1·h−1 for MA could be achieved with a relatively high selectivity of 85% on the optimal 17.5Cs/Beta40 catalyst. While the undesired catalytic deactivation behavior resulting from the accumulation of alkyl-substituted single-ring aromatic species in the micropores of catalyst was found during the reaction by employing FT-IR, GC–MS, TGA and UV–vis analysis, which could be easily regenerated by thermal treatment at 400 °C and air atmosphere. [ABSTRACT FROM AUTHOR]

Livestock wastewater contains a large amount of nutrients that are available for recovery. In this study, a proof of concept process based on forward osmosis (FO) was proposed and investigated for in situ formation of struvite from digested swine wastewater. This FO system took advantage of a drawback – reverse solute flux (RSF) and used the reverse-fluxed Mg 2+ for struvite precipitation, thereby accomplishing recovery of both water and nutrient. With 0.5 M MgCl 2 as a draw solution, high-purity struvite formed spontaneously in the feed solution and the water flux through the FO membrane reached 3.12 LMH. The precipitated struvite was characterized and exhibited a similar composition to that of commercial struvite. The FO system achieve >50% water recovery and >93% ammonium nitrogen removal from the digested swine wastewater; in particular, it obtained >99% phosphate recovery, much higher than 60.7% removal via direct MgCl 2 addition (without FO treatment). The recovered products (both struvite and water) could potentially generate a value of 1.35 $ m −3 . The results of this study have demonstrated the feasibility of nutrient recovery from livestock wastewater promoted by FO treatment. [ABSTRACT FROM AUTHOR]

• A kind of effective acidic polymeric ionic liquid was developed for ethylene hydroesterification. • The crucial role of hydrogen bond in ethylene hydroesterification was identified. • The detailed mechanism of ethylene hydroesterification was proposed using in - situ spectroscopic characterization. • The kinetic behavior of ethylene hydroesterification was revealed. Hydroesterification of ethylene with carbon monoxide (CO) and methanol (MeOH) for preparing methyl propionate (MP) has stimulated researcher's attention in recent years. Herein, the palladium-phosphine catalyzed ethylene hydroesterification with the promotion of acidic poly ionic liquids (APILs) for direct MP synthesis was developed. Series of APILs samples having different anions and acid densities were prepared and their structural properties were characterized by employing NMR, FTIR, TG and XPS. The anion type and acid density in APILs shown great influence on the catalytic performance due to the electronic effect and proton supply capacity related to Pd-H species formation. The hydrogen bond formed through the interaction between the anion of APILs and methanol could effectively promote the ethylene hydroesterification. The substrate extension experiments revealed the polarity and steric hindrance of alcohol would impact ethylene conversion. The mechanistic studies using in-situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) unraveled that the hydroesterification started with the activation of palladium complex to Pd-H species by CO, followed by the sequential formation of Pd-C 2 H 4 , Pd-alkyl and Pd-acyl intermediate species and consequential product MP. As a result, 94.4 % ethylene conversion could be achieved with 100 % selectivity toward MP at 80 °C and 2 MPa. No obvious deactivation behavior was observed for this kind of palladium catalyst after ten recycling experiments. The kinetic studies revealed the activation energy of ethylene hydroesterification is 59.3 kJ/mol. [ABSTRACT FROM AUTHOR]

[Display omitted] • A double-layer coating strategy is used to enhance the performance of SiO x anode. • The dual-shell structure consists of an Sn inner layer and N-doped outer layer. • The inner Sn can improve electronic conductivity and charge transfer kinetics. • The outer N-doped carbon shell can further maintain the structural integrity. • The dual-shell SiO x /C@Sn@NC anode exhibits excellent lithium storage ability. SiO x -based anode materials (0 < x < 2) have been regarded as an appealing candidate for anode material of commercial Lithium-ion batteries accounting for their ultrahigh theoretical capacity and low cost. However, its large-scale applications have been hampered by the serious volume expansion during repeated cycles, low intrinsic conductivity and unsatisfactory initial Coulombic efficiencies. Herein, to address these inherent deficiencies, a hierarchical SiO x -based anode with double-layer coatings of Sn inner layer and N-doped carbon outer shell is elaborately designed by a facile two-step hydrolysis process and polymer coating technology. Benefiting from the "synergistic effect" between Sn and SiO x at different working potentials and a well-designed double-layer coating structure, the resultant SiO x /C@Sn@NC anode displays excellent electrochemical properties, including an enhanced initial Coulomb efficiency (73.3%) efficiency, higher reversible capacity (991 mAh g−1) and superior long lifespan. Moreover, comprehensive characterization based on the reaction kinetics and structural stability proved that such enhanced ICE and cycling stability of anode material stem from its unique double-layer coating structure and multiple active components, which can significantly improve the diffusion of ion and charge transport, stabilize solid-electrolyte interphase (SEI) layer and absorb the expansion stress of electrode. Therefore, this study provides an efficient and feasible strategy to overcome the limitations of high-capacity SiO x -based anode materials via hybridization design with various active components and a double-layer coating strategy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Self-assembly by electrostatic interaction between silane and MOF ligand. • The activation mechanism of electrochemical inert metal Co in SiO x materials was investigated. • The catalytic action of atomic Co site activates Si O bond and Li O bond to increase SiO x capacity and coulomb efficiency. • High mechanical strength and high conductivity Co nanoparticles enhance the conductivity and cycling stability of SiO x. The ultra-high theoretical capacity of silicon-based (Si) materials makes them promising anode materials for high energy density lithium-ion batteries. Unfortunately, the dramatic volume change (∼300%) and low electrical conductivity of silicon have severely hindered the commercial use of silicon anodes. Silicon suboxide (SiO x) is one of the ideal candidates for high energy density batteries due to its reduced swelling and lower cost as compared to silicon. However, it remains a huge challenge to address the low conductivity, low (initial) coulombic efficiency and apparent volume effects of SiO x. In this paper, SiO x /Co@C composite anode materials loaded with metal Co nanoparticles were uniformly and efficiently prepared by using 3-aminopropyl triethoxysilane (APTES) as silicon source and Co-MOF as Co source via molecular self-assembly strategy. The experimental results and density functional theory (DFT) calculation showed that the catalytic action of embedded Co nanoparticles had activated the silico-oxygen bond of SiO x and the irreversible product Li 2 O, thereby improving the initial coulombic efficiency (ICE) and enhancing the reversible capacity. At the same time, the metal Co with mechanical rigidity and electrical conductivity alleviated the volume fluctuation during alloying and improved the charge transfer capacity and ion transport rate of the composite. When compared with SiO x @C anodes, SiO x /Co@C-600 composites showed higher initial CE, superior cyclic stability and good rate performance. In particular, the successful matching of the anode with the lithium iron phosphate (LFP) cathode in full cell systems validated the possibility of its practical application. This work provides important insights into the application of Si-based materials in lithium-ion battery electrode materials and the development of high energy density batteries. [ABSTRACT FROM AUTHOR]

The hollow Si nanospheres modified by the mechanically robust titanium dioxide (TiO 2 ) shell and the uniform carbon layer are intentionally designed and successfully prepared as the anode active material of high performance lithium-ion batteries. The effects of the robust TiO 2 shell and the uniform carbon layer on the structure and electrochemical performances for the Si@TiO 2 @C nanospheres are studied in detail by X-ray photoelectron spectroscopy, transmission electron microscopy, X-ray diffraction and charge/discharge tests. The results show that the hollow structure of the Si core can spontaneously absorb the huge volume expansion stress, the robust TiO 2 shell is used as a compact fence to promote the expansion towards the interior of the Si cavity instead of the exterior in the processes of charge/discharge, and the uniform carbon layer can effectively enhance the electrical conductivity and further control the integrity and stability of the well-wrapped core-shell-shell framework. Typically, the resultant hollow Si@TiO 2 @C nanospheres exhibit a high initial discharge capacity of 2557.1 mAh g −1 with coulombic efficiency of 86.06% as well as a large recuperative discharge capacity of 1270.3 mAh g −1 after 250 cycles at 1 A g −1 with a mean coulombic efficiency of 99.53%. Therefore, the hollow Si@TiO 2 @C nanospheres prepared by one-step sol-gel coating process show outstanding electrochemical properties and are considered as a prospective candidate to the adhibitions of the anode material for new generation power LIBs. [ABSTRACT FROM AUTHOR]

The competitive sorption of As(V) and Cr(VI) on the novel and uniform carbonaceous nanofibers (CNFs) was investigated in single/binary-metal systems. The presence of Cr(VI) showed a greater inhibitory effect on the sorption of As(V) in binary As–Cr system, especially at higher Cr(VI) concentrations. The maximum sorption capacities of Cr(VI) and As(V) on CNFs in single-metal systems at pH 5.0 and 303 K were calculated as 2.36 and 0.67 mmol/g, respectively, by Langmuir equation. XPS results demonstrated that only As(V) species was present at the CNFs surface, whereas both Cr(VI) and Cr(III) species existed on the CNFs surfaces, suggesting the partially reduction of Cr(VI) to Cr(III) by CNFs. According to the macroscopic and spectroscopic analysis, both inner-sphere and outer-sphere surface complexation contributed to the sorption process of Cr(VI), in contrast to the electrostatic outer-sphere sorption of As(V) on CNFs. The inner-sphere Cr complexes might arise from the covalent bonding between Cr(III) and oxygen-containing functional groups of CNFs. The findings herein highlight the higher chemical affinity of CNFs for Cr(VI) relative to As(V), as a consequence of the redox reaction of the strongly toxic Cr(VI) with CNFs. [ABSTRACT FROM AUTHOR]

[Display omitted] • A special coating show a stiff surface and strong adhesion to substrate. • Showing good self-healing ability and 4H hardness by strong and weak coordination. • Better self-healing efficiency in humid and hot environments. • An innovative method to prepare "inner soft external hard" coatings. To reduce pollution and maintain sustainable development, environmental friendly waterborne coatings as a replacement for conventional oil-based coatings have drawn lots of attention and been widely studied recently. It is a challenge to overcome the inherited weakness of waterborne coatings including poor scratch-resistance, low hardness and short lifespan. Herein, we have developed a scratch-resistant and self-healing waterborne coating of poly(urethane-urea), which contains a dual metal coordination structure of Zn(II)-carboxyl and Zn(II)-diamidepyridine by using the method of ions penetration. The addition of zinc ions has given dense metal coordination bonds on the coating surface, which has greatly increased the surface hardness (from B to 4H) and scratch-resistance, while the inner layer keeps excellent adhesion (>1.5 MPa) to substrates because of less metal ion penetration to the inner. What's more, the coating exhibits outstanding self-repairing performance, and the repair ability is better under hygrothermal condition. Atomic force microscope (AFM), dynamic mechanical analysis (DMA) and thermal analysis were used to characterize the self-healing and hardening mechanisms of the coatings. These results are expected to provide a useful method to improve the overall strength of waterborne coating. [ABSTRACT FROM AUTHOR]