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The nanostructures of silica-encapsulated NiO nanoparticles (NPs) doped with La, Ce, Ba, Co, Cu, and Fe were prepared and tested as catalysts for the partial oxidation of methane to syngas. Techniques that include TEM, XRD, Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (TPR), and O2 temperature-programmed oxidation (TPO) were employed to characterize the fresh and used catalysts to understand the structure-performance relationship. The La-doped Ni@SiO2 catalyst is superior to those doped with other elements. The effect of the reaction conditions on the catalyst performance over the best catalyst were also studied. The La2O3 species that were distributed uniformly throughout the NiO or Ni cores not only modify the core surfaces, but also enhance the resistance toward surface coking, which results in superior catalyst activity and durability. [ABSTRACT FROM AUTHOR]

Abstract: In this work the controlled SiO2 deposition on the HZSM-5 of medium (M-) and small (S-) sized grains is accomplished through the mild steam-pretreatment of zeolites (to modify the density of surface OH groups) followed by chemical liquid deposition (CLD) process. The amount of deposited SiO2 is tunable by varying the conditions of steam-pretreatment and/or CLD process, which allows quantitative correlating the changes of sample characteristics with the amount of deposited SiO2. NH3-TPD, pyridine and 2,6-DBT-pyridine adsorption infrared spectroscopic studies revealed the effect of surface SiO2 deposition on strength (weak and strong), type (Brønsted and Lewis), and location (external) of acid sites of HZSM-5. The external Brønsted acid sites of more than 75% are diminished upon SiO2 deposition of 13wt%. Due to pre-existing extra Na+ in S-HZSM-5, less amount of SiO2 deposition or P-doping will cause more obvious enhancement in para-selectivity on S-HZSM-5. The present study revealed that with the integrated modifications of SiO2 deposition and P–Ni doping on S-HZSM-5, toluene conversion of 31% and para-selectivity of 91% can be achieved. It was also found that doping of 5wt% Na and 6wt% P to M-HZSM-5 (free of silylation) can give p-xylene selectivity of ∼80% at toluene conversion of ∼26%. SiO2 deposition can more obviously reduce the strong acid sites, and P–Ni doping seems also to affect Lewis acidity. Low density of Brønsted (external)/Lewis acid sites and controlled diffusivity of HZSM-5 would be favorable for p-xylene generation in toluene alkylation with methanol. [Copyright &y& Elsevier]

Resins have enormous potential in the removal of naphthenic acids (NAs) from transformer oil due to their rich porosity and high mechanical and diversified functionality, whereas their poor adsorption capacity limits application. In this work, the polystyrene-diethylamine resin (PS-DEA-x) was prepared by grafting diethylamine (DEA) onto chloromethylated polystyrene (PS-Cl) resin to efficiently adsorb cyclopentane carboxylic acid from transformer oil for the first time. The characterization analysis results indicated that amine contents were significantly enhanced with the increase in DEA. Particularly, resin with a molar ratio of 1:5 depending on chloromethyl to DEA (PS-DEA-5) exhibited the highest amine contents and efficient adsorption of cyclopentane carboxylic acid (static adsorption capacity up to 110.0 mg/g), which was about 5 times higher than that of the pristine PS-Cl. The thermodynamic and kinetic studies showed that the adsorption behaviors could be well fitted to the Langmuir isotherm equation and pseudo-second-order rate equation. Moreover, it was found that 1 g of the PS-DEA-5 can decontaminate about 760 mL transformer oil to meet reuse standards by a continuous stream, indicating its potential application in industry.

Chromium based metal-organic framework (MIL-53(Cr)) has enormous potential in the removal of organic contaminants from aqueous solutions due to its outstanding water stability, whereas its poor adsorption capacity limits the application. In this study, La/LaF 3 -MIL-53(Cr) was successfully synthesized by taking the advantages of La doping and LaF 3 encapsulation with one-step hydrothermal method. Diverse analysis tools were utilized to verify that La not only existed in the framework, but also was loaded in the pores in the form of LaF 3 . The adsorption experiment results demonstrated that 0.3-La/LaF 3 -MIL-53(Cr) exhibited significantly improved adsorption capacity by four times compared with the pristine MIL-53(Cr) material. XPS and FTIR revealed that the affinity of La to tetracycline was significantly stronger than that of Cr and the excellent dispersion of LaF 3 in the material may also be the cause of the increase in adsorption capacity. This study described a simple method to combine two different forms of modification and the modified material was potential for tetracycline adsorption., (Copyright © 2021 Elsevier B.V. All rights reserved.)

An efficient strategy (spontaneous deposition to enhance noble metal dispersity and core-shell confinement to inhibit noble metal sintering) is presented to synthesize highly active and thermally stable Ru/ZrO2@SiO2 catalysts for dichloroethane combustion.

At present, activated carbon (AC) derived from industrial wastes has a great practical significance. In this work, residue activated carbon (RAC) was successfully synthesized from catechol distillation residue by a simple activation process based on two steps. The optimized RAC (RAC-800, activated at 800 °C) had high specific surface area (1800 m 2 /g) and large total pore volume (0.91 cm 3 /g). RAC-800 portrayed the evident increase of the graphitic structure and possessed abundant functional groups. Catechol (CC), phthalic acid (PA) and dimethyl phthalate (DMP) were chosen as typical pollutant to investigate the effect of different functional groups on adsorption aromatic compounds, and the equilibrium adsorption capacity of RAC-800 for CC, PA and DMP was 221.5, 365.0 and 449.9 mg/g, respectively. The adsorption behaviors were systematically studied by the combination of kinetic and thermodynamic model. The adsorption process was dominated by the π-π interaction, assisted by hydrogen bonding, hydrophobic and electrostatic interactions. In addition, regeneration study showed that the adsorption capacity can still remain over 88.5% after five cycles. In total, fine chemical distillation residues are promising to turn into the precursor of activated carbon, which has potential to be used as a good adsorbent for removal of aromatic compounds., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The simultaneous shaping and confinement of Cu-based MOP in alginate-SiO2 spheres significantly enhance the mechanical strength and leaching resistance of Cu-MOP. The resulting MOP-alginate-SiO2 is shown through chemical fixation of CO2 to exhibit improved product yield over the parent Cu-MOP and Cu-alginate-SiO2.

The specific mechanism of migraine chronification remains unclear. We previously demonstrated that synaptic plasticity was associated with migraine chronification. EphB receptors and their ligands, ephrinBs, are considered to be key molecules regulating the synaptic plasticity of the central nervous system. However, whether they can promote the chronification of migraine by regulating synaptic plasticity is unknown. Therefore, we investigated the role of ephrinB/EphB signaling in chronic migraine (CM). Male Sprague-Dawley rats were used to construct a chronic migraine model by dural infusion of an inflammatory soup for 7 days. We used qPCR, western blot, and immunofluorescence to detect the mRNA and protein levels of EphB2 and ephrinB2. The paw withdrawal latency and paw withdrawal threshold were measured after lateral ventricle treatment with EphB1-Fc (an inhibitor of EphB receptor). Changes in synaptic plasticity were explored by examining synaptic-associated proteins by western blot, dendritic spines of neurons by Golgi-Cox staining, and synaptic ultrastructure by transmission electron microscopy. We found that the expression of EphB2 and ephrinB2 increased in CM. The administration of EphB1-Fc relieved hyperalgesia and changes in synaptic plasticity induced by CM. In addition, EphB1-Fc inhibited the upregulation of NR2B phosphorylation. These results indicate that ephrinB/EphB signaling may regulate synaptic plasticity in CM via NR2B phosphorylation, which suggests the novel idea that ephrinB/EphB signaling may be a target for the treatment of migraine chronification., (Copyright © 2019 IBRO. Published by Elsevier Ltd. All rights reserved.)

Catalytic oxidation can efficiently eliminate nitrogen-containing volatile organic compounds (NVOCs) and suppress the generation of toxic NO x in order to avoid secondary pollution. In this study, mesoporous SiO 2 -confined LaMnO 3 perovskite nanoparticles with high dispersion were successfully prepared by a citric acid-assisted deposition method (LMO/SiO 2 -SD) and tested for the oxidation of n -butylamine. The method utilized the synergistic effect of abundant active hydroxyl groups existing on the SiO 2 gel surface and citric acid, rendering the metal ions more uniformly scattered on the SiO 2 surface. Strikingly, the LMO/SiO 2 -SD sample exhibited the optimum catalytic performance ( T 90 at 246 °C) and the highest N 2 selectivity, which was mainly ascribed to its abundant surface acid sites, superior low-temperature reducibility and higher ratio of surface Mn 4+ species. The apparent activation energy ( E a ) for n -butylamine oxidation over LMO/SiO 2 -SD sample was 29.0 kJ mol -1 . Furthermore, the reaction mechanism of n -butylamine oxidation was investigated by in situ FITR and a reasonable reaction route for n -butylamine oxidation over the LMO/SiO 2 -SD sample was proposed., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Solid base catalysts featuring green, robustness, and high activity play an important role in the current fine-chemical and petrochemical industry. Normally, the generation of supported K 2 O by thermal decomposition of KNO 3 requires high temperature, and this process can sometimes destroy the structure of supporting materials. We herein report a solvent-assisted stepwise redox (SASR) approach to generate zeolite NaA-supported K 2 O, which we call K 2 O/NaA, that function as the solid base catalyst for Michael addition reaction between ethanol and ethyl acrylate. The solvent-assisted redox decomposition process of KNO 3 at elevated temperature was investigated by thermogravimetry-mass spectrometry. It reveals that after reducing a minor amount of KNO 3 at 400 °C, the organic solvent decomposes to form carbon, which promotes the reduction of KNO 3 to generate strong basicity on the zeolite NaA at 600 °C. The resulting material, K 2 O/NaA-S, exhibits improved catalytic activity in Michael addition reaction over other benchmark base catalysts that have been used in this reaction. This catalyst is durable for at least four catalytic cycles without apparent loss in activity. K 2 O/NaA-S exhibits larger reaction rate constant yet lower activation energy than K 2 O/NaA prepared by thermal decomposition method. The SASR approach described in this paper represents a new blueprint for the generation of the supported alkali oxide as the solid base catalyst., Competing Interests: The authors declare no competing financial interest.

We reported the morphology-directed synthesis of Co(3)O(4) nanotubes via interfacial reaction of NaOH with pre-fabricated CoC(2)O(4)·2H(2)O nanorods based on modified Kirkendall effect. The as-obtained Co(3)O(4) nanotubes showed excellent activity and durability in catalytic combustion of CH(4)., (This journal is © The Royal Society of Chemistry 2012)