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HY zeolite is commonly considered to have a suitable pore structure for alkylation of aromatic. However, coke deposition results in catalytic activity falling rapidly because of its strong acidity. Herein, we prepared WO3/HY zeolite catalysts by liquid phase deposition method with phosphotungstic acid as the precursor, and their catalytic activities were evaluated by alkylation of naphthalene and n-tetradecene (C14H28). Characterizations showed that WO3 increased acid density and optimized the distribution of surface acidity and pore structure. The process not only increases the W5+ content which can increase the catalytic activity, but also reduces the reaction temperature to extend the service life. Both advantages of the catalysts achieved 96.12% conversion of naphthalene and 97.46% selectivity of monoalkylnaphthalene.

β Zeolite/bentonite composite was synthesized by simple kneading as catalyst for condensation reaction of aniline to diphenylamine. The experiment which was conducted at 320 °C under 2 MPa with a liquid hourly space velocity (LHSV) of 2 h−1 showed that the Hβ zeolite loading 25% clay exhibited the highest activity (9.9% aniline conversion) and selectivity. Pilot experiments (315–320 °C, 2 MPa, LHSV of 0.20–0.22 h−1) have also confirmed that the catalyst had good stability. The crystalline structure, acidic property and textural property of the catalysts were characterized by XRD, Py-IR, N2 adsorption–desorption. Moreover, according to the thermodynamic analysis, the condensation of aniline to diphenylamine is an exothermic reaction, indicating that too high temperature operation is unfavorable for the reaction. The studied β zeolite/bentonite composite is of promising efficiency in condensation of aniline to diphenylamine.

Compared to single-crystal SiC, nanocrystalline SiC with high densities of stacking faults has been reported to be much more resistant to amorphization under self-ion and electron irradiations. This study examines H2+ ion irradiation-induced amorphization in nanocrystalline 3C-SiC with dense stacking faults using transmission electron microscopy. The results show that full amorphization at room temperature occurs at a comparable dose to that for its single-crystal SiC counterpart under the identical irradiation conditions. Both materials are amorphized as a result of local damage accumulation. The formation of the nucleation sites for amorphization is not appreciably affected by the presence of stacking faults and grain boundaries. The behavior may be attributed to the significant chemical effects of the implanted H atoms that may completely immobilize the point defects in SiC at room temperature. The results suggest cautions be excised to use nanocrystalline SiC materials in high H irradiation environment at room temperature. Further studies of the H behavior at elevated temperatures are warranted.

The hydrogenation catalyst plays an important role in removing trace olefins from aromatics. In this work, a Cu/ZnO/montmorillonite catalyst was developed. The Cu/ZnO/montmorillonite catalyst is not only comparable in performance to the noble metal Pt/montmorillonite catalyst, but also has greater potential because the activity of the catalyst at low hydrogen flow is almost the same as that at high hydrogen flow. Moreover, aromatic cracking will not occur under the action of the Cu/ZnO/montmorillonite catalyst. The activity of the modified catalyst used to remove olefins is stable at about 92% at low weight hourly space velocity (WHSV). The three functions of ZnO are summarized as follows: (i) Zinc oxide is beneficial to restore the BET surface area of the Cu-based catalyst. (ii) Zinc oxide can improve the amount of Cu that can be reduced by hydrogen. (iii) ZnO increases the grain size of Cu2(NO3)(OH)3, resulting in a higher reduction temperature for Cu-based catalysts.

This study presents experimental results on the influence of cellulose particles on the breakdown characteristics of transformer oil in a highly non-uniform field under lightning impulse voltage. The experimental results show that as the particle content increases, the breakdown voltage reduces with little change in the breakdown time lag. At the same cellulose particle content, the oil breakdown voltage under oscillating lightning impulse (OLI) is lower than that under standard lightning impulse (SLI) and the breakdown time lag under OLI is longer than that under SLI. The impulse wave oscillation has a large effect on the accumulation of particles around the high voltage electrode and cellulose particles affect the development of the streamer process. At mid to high particle content the accumulation of particles around the high voltage electrode causes a decrease in the conductivity of the surrounding oil. This work contributes to the understanding of the effect of cellulose particles in oil and breakdown and on oscillating waveforms and provides guidance for lightning impulse tests on oil-immersed power transformers in the field.

By hetero atom doping, a nitrogen-doped porous carbon was synthesized and applied to catalytic oxidation removal of NO. The synthesis conditions and NO removal process conditions of the modified carbon material were investigated, including calcination temperatures, impregnation amount, NO inlet concentration (100–500 ppm) and catalytic reaction temperature. The results showed that the dicyandiamide impregnation solution concentration of 0.5 M, and the calcination temperature of 600 °C performed the best in the preparation of structurally stable nitrogen-modified carbon. Due to the formation of a large number active centers of pyridine nitrogen (N-6) groups and graphitic nitrogen (N-Q) groups, the optimal conversion rate of NO could reach 67.2%.

H-ZSM-5, H-IM-5, and H-IM-5(DS) zeolites were synthesized as highly active and shape selective catalysts for the alkylation of benzene with methanol. The samples were characterized by N2-adsorption-desorption, XRD, SEM, TEM, NH3-TPD, and Py-FTIR. The benzene conversion and xylene selectivity were in the same order H-IM-5(DS) > H-IM-5 > H-ZSM-5, while the toluene selectivity was in the reverse order. Combined with the analysis of pore structure and TEM, H-IM-5(DS) zeolite was equipped with more meso/macropores and it exhibited even better catalytic properties. The optimum reaction condition with H-IM-5(DS) as catalysts was obtained.

Excited-state intramolecular proton transfer (ESIPT) has been well investigated in recent years, whereas we investigated the system containing double hydrogen bonds. We explore the influence of sol...

To selectively adsorb dimethyl disulfide (DMDS) from its competition components, such as methyl tert-butyl ether (MTBE), the shell layer of silicalite-1 crystals was synthesized on a commercial Y z...

Mesoporous silica nanocarriers (MSNs) are appealing in terms of their large cavity surface area and high loading capacity, but they have been suffering from premature cargo release. Herein, we report a gated smart MSN that is sensitive to low oxygen concentration (i.e., hypoxia) via taking advantage of the superior electron-accepting ability of the azobenzene moiety. The azobenzene polymer was employed as the responsive gate-keeper that was deposited on the MSN surface, followed by coating with amphiphilic Pluronic F68 for steric stabilization. The obtained nanocarriers were less than 200 nm. The

A phosphorus modified HZSM-5 sample with excellent p-xylene selectivity was successfully obtained by a method of reversing the external surface ZSM-5 crystals to positive charged by HDTMA, which could selectively deposit the phosphorus on the external surface and pore entrance. The texture properties were characterized by XRD, XRF and N2 adsorption–desorption. The accessibility of acid sites was determined by NH3-TPD and Py/Coll-IR. The solid-state NMR measurement indicated that more phosphorus did not enter the pores of the MZS-1.5P sample and existed as H4P2O7 or polyphosphates not connected to aluminum. Applied to alkylation of toluene with methanol, MZS-1.5P sample all exhibited excellent para-selectivity at reaction temperatures of 360–420 °C and WHSV of 1.0–4.0 h–1. The TPD of xylene analysis showed that the interactions between diffusing molecule and surface of ZSM-5 as well as the geometric factors play important roles in the diffusion process.

A heterogeneous Cu modified Y zeolite is prepared for acetylene carbonylation, and acrylic acid yield is up to 86%; this catalyst could maintain ∼50% of initial activity even after three catalytic cycles. Regenerating the spent catalyst in air followed by N2 could restore the activity to 80%. Multiple measurement techniques, including XRD, ICP, XPS, NH3-TPD, TGA, Raman and SEM are carried out to obtain a deep understanding of the catalyst deactivation. During the reaction process, unreacted acetylene is pyrolyzed, solubilized, diffused, accumulated and solidified as disordered carbonaceous particles on the catalyst, then transferred to ordered filaments. At the same time, CuO is dissolved into the reaction liquid and only Cu+ is left, which reduce the acidity of catalyst in both amount and strength. Results show that factors causing the catalyst deactivation obey the following order: coke deposition > copper loss > acidity weakening > crystallinity collapse.

In this work, sulfated zirconia (SZ) was prepared by a solvent-free method, ammonium sulfate ((NH4)2SO4) and sulfamic acid (NH2SO3H) were as sulfur sources, respectively. The resulting catalysts were characterized by powder X-ray diffraction (XRD), thermogravimetric analysis and differential scanning calorimetry (TGA-DSC), N2 adsorption–desorption isotherms, inductively coupled plasma (ICP) and pyridine-FTIR. The characterization of the catalysts revealed that SZ prepared with (NH4)2SO4 as sulfur source contained more Lewis acid sites and less Brønsted acid sites. The effects of sulfur sources on the catalytic activity of catalysts were studied. Catalytic testing showed that SZ prepared with (NH4)2SO4 as sulfur source had a better catalytic performance for removing trace olefins from aromatics. Keywords: Aromatics, Olefins, Sulfur sources, Sulfated zirconia

In this work, we explore the excited-state intramolecular proton transfer (ESIPT) mechanisms and relative solvent effects for three novel 3-hydroxylflavone derivatives (i.e., HOF, SHOF, and NSHOF) in acetonitrile, dichloromethane, and toluene solvents. Through calculations, we optimize the structures of HOF, SHOF, and NSHOF. Through the analysis of a series of structural parameters related to hydrogen bonding interactions, it could be found that the hydrogen bonds of the three derivatives are all enhanced in the S1 state, and more importantly, the excited-state hydrogen bonds of HOF are stronger than those of SHOF and NSHOF. In order to explore the effects of solvent polarity, we analyze the core-valence bifurcation (CVB) index, infrared (IR) vibration spectrum, and the potential energy curves. We find that for HOF, SHOF, and NSHOF, the strength of the excited-state hydrogen bonds increases as the solvent polarity decreases. The solvent polarity dependent ESIPT mechanisms pave the way for further designing novel flavonoid-based solvatofluorochromic probes in future.

A kind of porous carbon spherical material with high specific surface (SBET=1,292 m2/g) was synthesized from deactivated methyl tert butyl ether (MTBE) resins with KOH as the activator (KA...

NaOH treated silicalite-1/CuYOH core–shell composites were synthesized at the mass ratio of tetraethyl orthosilicate (TEOS)/tetrapropylammonium hydroxide (TPAOH)/ethanol/H2O/CuY = 20 g (0.096 molar):19 g (0.0234 molar):17 g (0.369 molar):87 g (4.8293 molar):5 g to achieve the selective adsorption desulfurization of dimethyl disulfide (DMDS) from methyl tert-butyl ether (MTBE). As the core zeolite, CuY was obtained by Cu2+ ion-exchange on NaY. After alkali treatment, NaY zeolite was provided with more loading positions for silicalite-1 crystals owing to the desilication effect of NaOH. Results showed that the core–shell YOH-CuCl2 displayed the best performance in desulfurizing DMDS from MTBE with a sulfur adsorption capacity of 37.073 mgs/gadsorbent for the sake of its significant mass gain and compact silicalite-1 coatings. The preparation of silicalite-1/CuYOH core–shell composites and the shape selective adsorption mechanism of desulfurizing DMDS on these core–shell composites were expounded.

Metallic oxides were introduced into the synthesis of sulfated zirconia. Catalytic activity was tested by an olefin removal reaction. By combining the analysis from the aspect of catalyst morphology, sulfur state and surface acid property, we concluded that the incorporation of metallic oxides has three important positive effects on the environmental friendly solvent-free preparation: (i) it inhibited the phase transition during calcination and promoted the existence of tetragonal ZrO2, which is recognized as the valid phase; (ii) it increased the amount of S, especially S6+, which is the source of active sites; and (iii) it adjusted the surface acid property, extended the single service lifetime and reduced the deactivation rate.

Herein, a core–shell H-IM-5@meso-SiO2 hybrid material was synthesized by reversing the charge of the external surface of IM-5 crystals to a positive charge by PDDA that could induce an oriented self-assembly formation of the meso-SiO2 shell. The as-synthesized H-IM-5@meso-SiO2 composite was thereafter modified with phosphorus species to further enhance the selectivity of the target product. The sample morphology and structure were analyzed by electron microscopy technology, XRD, XPS and N2 adsorption–desorption. The effects of the meso-SiO2 shell and phosphorus species on sample acidity were investigated by NH3-TPD, FTIR spectroscopy and solid-state NMR measurements. The catalytic properties and characterization results revealed that the meso-SiO2 shell could passivate the external surface acids of the H-IM-5 crystals. The phosphorus modification could simultaneously adjust the surface acidity as well as the size of the pores and pore-openings. The TPD analysis of xylene showed that the sample surface acidity and geometric factors played important roles in the diffusion process of the diffusing molecules.

The excited-state intramolecular proton transfer (ESIPT) mechanism and photophysical properties of a series of 2-(1H-1,3-benzodiazol-2-yl)-3-hydroxy-4H-benzo[h]chromen-4-one (HBC4H) derivatives are explored theoretically. From these, a new explanation of ESIPT mechanism of 3-hydroxy-4H-benzochromone derivatives has been proposed. Firstly, three isomers are optimized in toluene solvent. through the analysis of the hydrogen bond parameters and infrared vibration spectrum, it is found that the hydrogen bonds of HBC4H should be strengthened in the S1 state. In order to explain the mechanism of ESIPT, the Boltzmann distribution and torsion forces of the three isomers are deliberated, and the searched transition state (TS) structures are depicted. It is discovered that the potential barriers are all lower than 5.00 kcal/mol in the S1 state, and HBC4H-Ia and HBC4H-Ic may coexist in the S0 state, and more significantly, among the three isomers, HBC4H-Ia may be the most favorable form of ESIPT.

Desulfurization of dimethyl disulfide (DMDS) from methyl tert-butyl ether (MTBE) has been studied on the silicalite-1/NaY core–shell composites. By changing the mass ratio of tetraethyl orthosilicate (TEOS)/NaY, the silicalite-1 shell synthesis condition was conducted at the mass ratio of TEOS/tetrapropylammonium hydroxide (TPAOH)/ethanol (EtOH)/H2O = (10, 15, 20, 25, 30 g):19 g:17 g:87 g ((0.048, 0.072, 0.096, 0.12, 0.144): 0.0234:0.369:4.8293 in molar ratio, where the mass of NaY zeolite was quantified to 5 g) by a hydrothermal synthesis at 180 °C for 24 h. Results showed that when the mass ratio of TEOS/TPAOH/EtOH/H2O/NaY = 20 g:19 g:17 g:87 g:5 g, the silicalite-1 coating could be dispersed and covered on the surface of NaY well (the thickness of silicalite-1 shell ranged from 100 to 400 nm) with the best sulfur adsorption capacity as 20.711 mgs/gadsorbent. The shape-selective adsorption mechanism of desulfurizing DMDS from MTBE on these core–shell composites was also elaborated.

Traditional antitumor nanomedicines have been suffering from the poor tumor targeting (ca. 1%) by the enhanced permeability and retention (EPR) effect, and the low drug loading (5%). It was postulated that engineering all-active nanoplatform could increase the therapeutic efficacy to enable the nanocarrier function as both vehicle and active ingredient. To achieve this, a photosensitizer, Ce6 was encapsulated within polymeric micelles with unsaturated fatty acids as the building blocks. Upon light irradiation, the singlet oxygen produced by Ce6 induced lipid peroxidation, resulting in the generation of both active free radicals and aldehydes. These supplementary radicals could exert cytotoxic effect for direct killing tumor cells. The aldehyde end-products induced significant cell cycle arrest at G

Redox-responsive polymer-drug conjugate micelles are excellent nanoscale vehicles for self-immolative intracellular drug delivery. To covalently connect the polymer and drug, disulfide-bearing linkers, such as 3,3’-dithiodipropionic acid (DDPA) and 4,4’-dithiodibutyric acid (DDBA), are used. In this paper, we report the influence of linker length on the therapeutic outcome of redox-sensitive conjugate micelles. Curcumin was selected as the model drug and it was conjugated to a multivalent methoxy poly(ethylene glycol)-polylysine copolymer with DDPA or DDBA as the linker. The obtained two polymer-curcumin conjugates were amphiphilic and could self-assemble into micelles that have a hydrodynamic diameter less than 100 nm. The loading of curcumin in both micelles was above 20% (w/w). Irrespective of the linker type, micelle disassembly was observed due to the collapse of the disulfide bond in a reducing environment. However, the rate of curcumin release was much faster with the DDBA linker than with the DDPA linker as the side product was a 5-membered ring with a low ring strain. The linker length-induced variation of curcumin release kinetics caused a significant difference in the intracellular drug concentration and a higher cytotoxicity was witnessed in three model cell lines (HeLa, PC3, and 4T1) for the micelles with a DDBA linker compared to those containing a DDPA linker. As expected, this phenomenon was also observed in HeLa tumor-bearing nude mice in vivo. The current work highlights the significance of linker length in engineering redox-responsive on-demand delivery systems.

Selective adsorption desulfurization of dimethyl disulfide (DMDS) from methyl tert-butyl ether (MTBE) has been studied on the silicalite-1/CuY core–shell composites. Different copper ion sources (CuCl2, Cu(NO3)2, and CuSO4) were investigated to form CuY as the core by Cu2+ ion-exchange on NaY zeolite. These silicalite-1/CuY core–shell composites were synthesized at the mass ratio of tetraethyl orthosilicate (TEOS)/tetrapropylammonium hydroxide (TPAOH)/ethanol/H2O/CuY = 20 g:19 g:17 g:87 g:5 g. Results showed that the core–shell Y-CuCl2 displayed the best performance in desulfurization of DMDS with a sulfur adsorption capacity of 32.882 mgs/gadsorbent, owing to its significant mass gain and compact coatings after being coated by silicalite-1 on Y-CuCl2. Also, the preparation process of CuY and the shape selective adsorption mechanism of desulfurizing DMDS from MTBE on the silicalite-1/CuY core–shell composites were expounded.

A palladium-nickel doped sulfated zirconia was prepared, and hydrogen spillover and bimetallic synergic effect were confirmed using this model catalyst. Isomerization of n-hexane indicated that palladium and nickel could enhance both the conversion rates and selectivity. The XRD and BET results showed that nickel had a strongly influence on the crystal form and catalyst structure. TG-DSC analysis showed the loaded nickel could decrease the sulfates concentrations. Therefore, the total acidity, especially the strong Bronsted acid sites decreased in the presence of nickel, as analyzed by pyridine IR spectroscopy. H2 TPR analysis indicated both the nickel and palladium could improve the reducibility of sulfated zirconia. And combined with XPS results, the nickel oxide was found easier to reduce in the presence of palladium, and higher reduction temperature could lead to the formation of NiAl2O4. Finally, the mechanisms of hydrogen spillover and reaction process were deduced.

Low-cost activated carbon (KAC) was functionalized by HNO3, (NH4)2S2O8 and air oxidation, respectively, to remove dibenzothiophene (DBT) from model fuel. The changes in physical and chemical properties of these activated carbons were characterized by thermal analysis, elemental analysis, nitrogen adsorption apparatus, Raman spectra, scanning electron microscope and Boehm’s titration method. HNO3 and (NH4)2S2O8 oxidation result in a significant decrease in pore structure, while air oxidation only causes slight pore reduction due to the re-activation by O2. The oxygen-containing functional groups (OFGs) increase markedly after oxidative modification, in which (NH4)2S2O8 oxidation is considered as the most efficient method with respect to the introduction of OFGs. HNO3 and (NH4)2S2O8 oxidation are more selective to generate carboxyls and lactones, whereas air oxidation creates more phenols, carbonyls and ethers. The DBT adsorption capacity follows the order: NAC (HNO3-oxidized KAC) > OAC (air-oxidized KAC) > KAC > SAC ((NH4)2S2O8-oxidized KAC), implying the introduction of OFGs is beneficial for the DBT adsorption process, especially for selectivity, but excessive OFGs have a negative effect on the removal of DBT. Thus, to achieve high DBT adsorption performance, there should be a trade-off between the micropore volume and the OFGs amount.

ESIPT reaction is one of the most extensively studied photochemical behaviors, and many organic chromophores are designed based on this mechanism. Oxazolinyl- and arylchalcogenazolyl-substituted hydroxyfluorenes are emission color-tunable chromophores, and they are used as efficient proton receptors in ESIPT-based chromophores. In this work, we concentrate on probing into the ESIPT behaviors of oxazoline-substituted hydroxyfluorenes (Oxa-OH), hydroxylated benzoxazole (BO-OH) and naphthoxazole (NO-OH) compounds. The π-extended constructions of proton receptors of these three compounds are expended successively. Structures are optimized and infrared (IR) spectra of electron excited state are calculated. Independent Gradient Model (IGM) function is also used to compare hydrogen bond interactions, and frontier molecular orbitals are further analyzed. It is found charge redistribution is favorable for promoting ESIPT process. The effect of π-expansion of proton acceptor on ESIPT behavior is also observed. Especially, the potential application of π-expansion in color regulation of crystal luminescence is promising.

Adsorption is a classical process applied to eliminate air pollutants with low-concentration of volatile organic compounds (VOCs). The evaporation induced self-assembly (EISA) method was used to efficiently load metal-oxide nanoparticles on the NaY zeolite to improve the adsorption capacity for VOCs. Dynamic and static adsorption experiments were applied to investigate the adsorption of toluene, isopropanol and acetone by Y@MxOy (M = Ni, Co, Cu, Mn) under dry (RH = 0) and wet (RH = 50%) conditions. Compared with NaY zeolite, Y@MxOy with uniformly dispersed nanoparticles of metal-oxide significantly improved the adsorption capacity of VOCs, and Y@CoO exhibited the optimal adsorption performance for isopropanol (189 mg/g) and acetone (124 mg/g) under RH = 50%, yet Y@MnO2 showed the best adsorption capacity for toluene (50 mg/g). Several important properties of the Y@MxOy composites were determined by XRD, N2 adsorption–desorption isotherm, SEM, TEM and EDS. Moreover, density functional theory (DFT) was used to systematically calculate the adsorption system and explored the mechanism of the weakening of competitive adsorption between VOCs and water molecules. The chemisorption of metal-oxides with the oxygen functional groups of VOCs greatly improves the adsorption capacity, which provides a new way to develop a neoteric adsorbent for VOCs.

To date, the scalable exfoliation of the resource-rich montmorillonite (MMT) into high-quality few-layered nanosheets still remains a grand challenge. Herein, a simple, nontoxic, and efficient strategy is proposed to exfoliate layered MMT into mono-layered MMT nanosheets (MMTNS) via thermal expansion gas-assisted exfoliation method. The essence of this method is that the high temperature expands the interlayer distance while weakens the van der Waals force between interlayer of bulk MMT and then the liquid nitrogen (L-N2) penetrated the interlayers can be quickly vaporized to exfoliate the MMT. With a high mass yield of 18–20%, the prepared MMTNS has a thickness around 1.9 nm and a reasonable aspect ratio (lateral dimension of 0.5 µm-3 µm). Meanwhile, no impurities were introduced during the whole procedure. Additionally, the exfoliated MMTNS with high specific surface area (402 m2 g−1) and more exposed acid sites is further applied for the removal of trace olefins from aromatics, the result shows higher olefin conversion (76.97%) than its parent bulk phase (50.66%). The possible reaction mechanism of removing olefins from aromatics was further proposed and investigated by gas chromatography-mass spectrometry (GC–MS).

The systematic research about the adsorption desulfurization and competitive behavior from 1-hexene over cesium-exchanged Y zeolites has been investigated. The structural properties of the adsorbents were characterized by X-ray diffraction (XRD), N 2 sorption (BET) and thermal analysis (TGA). The effects of calcination temperature, calcination atmosphere, and adsorption temperature were studied by the dynamic and static tests. The competitive adsorption mechanisms between thiophene and 1-hexene were studied by in-situ Fourier transform infrared spectroscopy (in-situ FTIR) and temperature-programmed desorption (TPD). CsY adsorbents exhibited high selectivity for thiophene even when a large amount of olefins exist. In-situ FTIR spectra of thiophene and 1-hexene adsorption indicated that both thiophene and 1-hexene were mainly adsorbed on CsY via π-complexation. The higher desorption activated energy and higher adsorption heat of thiophene than 1-hexene obtained by thiophene-TPD and hexene-TPD has revealed that thiophene is adsorbed more strongly in CsY adsorbents than 1-hexene.

In this research, low-cost activated carbons (ACs) derived from deactivated resin catalyst (DRC) for methyl tert -butyl ether synthesis were successfully prepared through carbonization and subsequent steam activation or KOH activation. Differences in physical and chemical properties of ACs and their performance on dibenzothiophene (DBT) adsorption from model fuel were investigated systematically. AC prepared by KOH activation (KSAC) has abundant micropores, whereas mesopores are the major part of AC prepared by steam activation (HSAC). Both KSAC and HSAC have few acidic groups, in accordance with their oxygen content. DBT adsorption performance is dependent largely on physical properties. The maximum adsorption capacity (16.1 mgS/g at 100 ppmS) and the longest breakthrough time (16 h, 10 h −1 WHSV) were observed for KSAC.

A high-aluminum-content sulfated zirconia was prepared by the kneading method, and the washing process was considered as a key factor. Catalysts were characterized by XRD, BET analysis, SEM, TG, FT-IR spectroscopy, pyridine IR spectroscopy, NH3 TPD, H2 TPR, and 27Al NMR spectroscopy, and the reactivity was evaluated by n-hexane isomerization. The results showed that the high-aluminum-content sulfated zirconia has a high activity after being washed with water. Moreover, the aluminum content was found to strongly influence the crystal form, catalyst structure, and acidity, as well as the anchoring effect on the labile sulfates. Actually, the higher the aluminum content was, the more sulfates were left in the catalyst samples after washing. The O—H and S═O stretching vibrations were shifted in the presence of aluminum or water. With the support of the aluminum coordination state, a hydrolysis model was deduced for different aluminum contents in the catalysts, and it can explain the formation of more Bronsted...

Catalytic reactions of acetylene have become a subject of renewed interest. However, recent literatures about the synthesis of acrylic acid by acetylene carbonylation were rare to be found. In our research, the yield of acrylic acid is greatly improved to ∼86% (242.85 g Acrylic acid/g Cat.·h) by using heterogeneous catalyst Cu(I)Y, against ∼70% from other reports using complex homogeneous catalyst. Y modified with different valence states copper were prepared by heating the precursor at various atmospheres and characterized by XRD, BET, XPS and FT-IR. More than one type of copper (Cu2+, CuO, Cu2O, Cu+ or Cu0) was found on one sample. Moreover, the distribution and the forming process of these types of copper were determined. According to FT-IR using pyridine or CO as probe, Cu+ at site II′ not only enhanced the acid strength obviously, but also promoted the formation of the most stable monocarbonyls. Furthermore, the strong acid site and the stable monocarbonyls are beneficial for the acetylene carbonylation.

Ferroptosis is an iron-dependent cell death pathway that can eradicate certain apoptosis-insensitive cancer cells. The ferroptosis-inducing molecules are tailored lipid peroxides whose efficacy is compromised in hypoxic solid tumor and lack of tumor selectivity. It has been demonstrated that ascorbate (Asc) in pharmacological concentrations can selectively kill cancer cells via accumulating hydrogen peroxide (H2O2) only in tumor extracellular fluids. It was hypothesized that Asc-induced, selective enrichment of H2O2 in tumor coupled with Fe3+ codelivery could simultaneously address the above two problems via boosting the levels of hydroxyl radicals and oxygen in the tumor site to ease peroxidation initiation and propagation, respectively. The aim of this work was to synergize the action of Asc with lipid-coated calcium phosphate (CaP) hybrid nanocarrier that can concurrently load polar Fe3+ and nonpolar RSL3, a ferroptosis inducer with the mechanism of inhibiting lipid peroxide repair enzyme (GPX4). The hybrid nanocarriers showed accelerated cargo release at acidic conditions (pH 5.0). The combinational approach (Asc plus nanocarrier) produced significantly elevated levels of hydroxyl radicals, lipid peroxides, and depleted glutathione under hypoxia, which was accompanied with the strong cytotoxicity (IC50 = 1.2 ± 0.2 μM) in the model 4 T1 cells. In the 4 T1 tumor-bearing xenograft mouse model, the intravenous nanocarrier delivery plus intraperitoneal Asc administration resulted in a superior antitumor performance in terms of tumor suppression, which did not produce supplementary adverse effects to the healthy organs. This work provides a novel approach to enhance the potency of ferroptotic nanomedicine against solid tumors without inducing additional side effects.

UiO-66 (Universitetet i Oslo) is one of the most known metal-organic frameworks with high hydrothermal stability. In this work, a series of UiO-66 were prepared using acetic acid as a modulator to produce linker defects. Samples were characterized by X-ray powder diffraction, nitrogen adsorption-desorption isotherms, thermogravimetric analysis and adsorptive desulfurization test. Results indicated that increasing the amount of acetic acid to 30% equivalent with respect to terephthalic acid did not have an obvious negative effect on the structure. At the same time, surface area and micropore pore volume are further increased from 988 $$\hbox {m}^{2}$$ /g, 0.34 $$\hbox {cm}^{3}$$ /g to 1424 $$\hbox {m}^{2}$$ /g, 0.54 $$\hbox {cm}^{3}$$ /g. Adsorptive desulfurization performance is also significantly improved from 6.0 mg/g to 7.9 mg/g. So, the linker defects produced by acetic acid can remarkably enhance the adsorption ability. Adsorptive desulfurization kinetics indicates that while indicating the monomolecular layer, chemical adsorption occupies the dominant position, and there is no special chemical force formed between the defects and dibenzothiophene. AcOH can improve the surface area of UiO-66 significantly. UiO-66 prepared with the new method has good adsorption desulfurization ability. The adsorption process can be described by pseudo-first-order kinetic model and Langmuir isotherm.

Decontamination of air or other gas streams loaded with low-concentration volatile organic compounds (VOCs) and high humidity is a prevalent task for adsorption using zeolites. Hydrophobic adsorbents were prepared with NaY zeolites as raw materials by the high-temperature hydrothermal treatment, and the degree of ion-exchange was considered as a key factor. Adsorbents were characterized by XRD, FTIR spectra, N2 adsorption-desorption isotherm, SEM, water contact angle, TG/DTG, and the adsorption capacities of water and toluene were evaluated by static adsorption test and dynamic adsorption breakthrough study. The results showed that high degree of ion-exchange was beneficial to dealumination from zeolite skeleton and crystal of zeolite remains intact in the high-temperature hydrothermal treatment. The framework silicon-aluminum ratio (SiO2/Al2O3) of modified zeolite obtained by high-temperature hydrothermal treatment reached 12.41 while the degree of ion-exchange was three (SY-3). Moreover, the hydrophobic index (HI) of SY-3 increased from 0.047 of initial NaY zeolite to 10.059. In addition, regeneration of SY-3 was easier than that of initial NaY zeolite. Our work also has further studied the mass transfer in the zeolite and mechanism of high-temperature hydrothermal treatment under the effect of different ion-exchange degree.

A series of modified HZSM-5 zeolites with different types of acid and different HCl concentrations treatments were synthesized, respectively. The crystal morphology, textural property and acidic property of the catalysts were characterized by XRD, N2 adsorption–desorption, NH3‐TPD, Py-IR and 27Al MAS NMR spectroscopy. The influences of acid treated types and acid solution concentrations in the pore structure, acidity and non-hydrocracking activity were investigated. The results showed that mesopores were successfully induced to HZSM‐5 zeolites after dealumination by HCl and H3PO4 treatment and the acid sites were redistributed. The acidic analysis revealed that the increase of LAS/BAS value was conducive to improving the non-hydrocracking cracking activity and gasoline yield of the samples. It was also observed that an appropriate amount of HCl treatment can not only play the role of dredge the channel of the zeolites, also introduce some new mesoporous. The hydrochloric acid treated sample (HZ-1.0HA) showed the best diesel non-hydrocracking cracking activity and gasoline yield.

Background Investigate immunoregulation and anti-tumor immunity of FoxP3+Tregs after treatment with rapamycin (RAPA/SRL) plus thymalfasin (Zadaxin) and Huaier extract (PS-T) in a hepatocellular carcinoma (HCC) rat model simulating HCC relapse after liver transplant (LT). Methods We successfully established a rat model simulating HCC relapse after LT using an optimized chemical induction method with TACROLIMUS, methylprednisolone, and diethylnitrosamine as identified by visible liver nodules and hematoxylin-eosin staining. The model rats were then treated with RAPA, Zadaxin, and PS-T. Immune status changes were analyzed by flow cytometry, and protein expression of Akt and mTOR was determined by western blotting. Cytokines were measured by ELISAs. Results Combined therapy by RAPA plus Zadaxin and PS-T obviously alleviated hepatic pathological changes and significantly decreased the levels of FoxP3+Tregs in peripheral blood, the spleen, and the liver (P

Nanoparticulate antitumor photodynamic therapy (PDT) has been suffering from the limited dose accumulation in tumor. Herein, we report dually hypoxia- and singlet oxygen-responsive polymeric micelles to efficiently utilize the photosensitizer deposited in the disease site and hence facilely improve PDT's antitumor efficacy. Tailored methoxy poly(ethylene glycol)-azobenzene-poly(aspartic acid) copolymer conjugate with imidazole as the side chains was synthesized. The conjugate micelles (189 ± 19 nm) obtained by self-assembly could efficiently load a model photosensitizer, chlorin e6 (Ce6) with a loading of 4.1 ± 0.5% (w/w). The facilitated cellular uptake of micelles was achieved by the triggered azobenzene collapse that provoked poly(ethylene glycol) shedding; rapid Ce6 release was enabled by imidazole oxidation that induced micelle disassembly. In addition, the singlet oxygen-mediated cargo release not only addressed the limited diffusion range and short half-life of singlet oxygen but also decreased the oxygen level, which could in turn enhance internalization and increase the intracellular Ce6 concentration. The hypoxia-induced dePEGylation and singlet oxygen-triggered Ce6 release was demonstrated both in aqueous buffer and in Lewis lung carcinoma (LLC) cells. The cellular uptake study demonstrated that the dually responsive micelles could deliver significantly more Ce6 to the cells, which resulted in a substantially improved cytotoxicity. This concurred well with the superior in vivo antitumor ability of micelles in a LLC tumor-bearing mouse model. This study presented an intriguing nanoplatform to realize interactively triggered photosensitizer delivery and improved antitumor PDT efficacy.

Heterogenization of homogeneous catalyst for acetylene carbonylation was carried out by preparing a series of Ni-modified catalysts (Ni-ZSM-5, Ni-IM-5 and Ni-MCM-41). Several important properties of the heterogeneous catalysts were determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES), XPS, XRD, N2 adsorption, pyridine-FTIR, SEM and TGA. Moreover, we used various activity criteria to dissipate perturbing factors, when we focused on the influence of surface structure and active site distribution. The result that Ni-IM-5 had the greatest TOFNi = 5107 g acrylic acid per g Ni per h showed that the surface structure of samples did not influence the catalyst performance significantly. In addition, the highest ratio of nickel sites/acid sites in Ni-MCM-41 represented the best active site distribution. Thus, Ni-MCM-41 has the highest TOFcat = 70.6 g acrylic acid per g cat. per h. Furthermore, stability testing of the catalysts showed the Ni-MCM-41 could be used four times, while others only twice.

Nano-NiO and Bi 2 O 3 modified NiO have been successfully prepared by precipitation method and used as catalyst for the carbonylation of acetylene to acrylic acid. The specimens were characterized by powder X-ray diffraction, N 2 adsorption–desorption, scanning electron microscopy, hydrogen temperature-program reduction and X-ray photoelectron spectroscopy. These results indicated that the introduction of Bi 2 O 3 to the catalyst greatly affected the physical and chemical properties of NiO. The catalytic performance of Bi 2 O 3 /NiO depends on the content of Bi 2 O 3 , and a composite oxide catalyst with 11.1 wt.% of Bi 2 O 3 showed significantly higher activity compared to its components in the pure phase.

The cryogenic interlaminar shear strength (ILSS) at cryogenic temperature (77 K) of glass fabric (GF)/epoxy composites is investigated as a function of the graphene oxide (GO) weight fraction from 0.05 to 0.50 wt% relative to epoxy. For the purpose of comparison, the ILSS of the GF/epoxy composites is also examined at room temperature (RT, 298 K). The results show that the cryogenic ILSS is greatly improved by about 32.1% and the RT ILSS is enhanced by about 32.7% by the GO addition at an appropriate content of 0.3 wt% relative to epoxy. In addition, the ILSS of the composite at 77 K is much higher than that at RT due to the relatively strong interfacial GF/epoxy adhesion at 77 K compared to the RT case.

Reaction of transition metal(II) salts with 2,2′-biimidazole (H2biim) and co-ligands formed a series of new complexes, [M(H2biim)2(bipy)2](NO3)2·2H2O (1–3) (M = Co, Ni, Zn), [Co(H2biim)2(bipy)](ClO4)2·3H2O (4), {[Cu(H2biim)2]3(μ-C3H3O4)2 (C3H2O4)2}·6H2O (5), [Co(H2biim)2(H2O)2](C3H3O4)2 (6) (bipy = 4,4′-bipyridine, C3H2O4 = malonate dianion, C3H3O4 = malonate anion). These complexes were characterized by single-crystal X-ray diffraction, and elemental analysis. All complexes except 4 were also characterized by luminescence spectra and thermogravimetric analysis. The crystal packing of these six complexes shows that cationic M(II)(2,2′-biimidazole) fragments are self-assembled to construct the 3D supramolecular networks by hydrogen bonding and π–π interactions. The 3D supramolecular networks are significantly affected by counter anion and co-ligands. In complexes 1–3, there are two sets of (4,4) nets which pass through each other to form inclined 2D interpenetration. Complex 4 is obtained by similar reactions as 1 Compared with 1, the only difference in 4 with the reactant Co(NO3)2·6H2O replaced by Co(ClO4)2·6H2O, but it has a very different structure. In 4, the 3D networks containing cavities of 23 × 23 A is formed. In complex 5, the uncoordinated waters form an infinite 1D pipe structure which is embedded in the 3D porous network. The acid–water ring and R22(9) synthons in complex 6 lead to the formation of (4,4) 2D network.

Reactions of transition metal(II) nitrate with 2,2′-biimidazole and 1,10-phenanthroline generated three new isostructural complexes, [Co(H2biim)3][Co(H2biim)2(phen)](NO3)4·2CH3OH·H2O (1), [Ni(H2biim)3][Ni(H2biim)2(phen)](NO3)4·3.5H2O (2), and [Zn(H2biim)3][Zn(H2biim)2(phen)](NO3)4·4H2O (3) (H2biim = 2,2′-biimidazole, phen = 1,10-phenanthroline). These complexes were characterized by single-crystal X-ray diffraction, elemental analysis, luminescent spectra and thermogravimetric analysis. The crystal packing of the complexes show that cationic [M(H2biim)3]2+ fragments are self-assembled to construct the 2-D supramolecular networks by hydrogen bonding and π–π interactions. The guest molecule [M(H2biim)2phen]2+ is well recognized by the N–H⋯O and O–H⋯O hydrogen bonds. In complexes 1–3, chiral guest molecules recognize the chirality of the host cations [M(H2biim)3]2+, which are assembled into 2-D nets with alternating Δ and Λ chirality resulting in the structure of racemates. The data observed in this paper suggest that the diverse hydrogen bonding modes between the nitrate and H2biim ligand identified here play a crucial role in the formation of 1–3.

A non-petroleum route to produce acrylic acid was investigated through hydrocarboxylation of acetylene with CO and water in the presence of Ni2O3 and cupric bromide as combined catalysts. The activity of Ni2O3 was compared with various homogeneous catalysts; the effect of initial total pressure, reaction temperature, molar ratio of CO/C2H2, the volume ratio of solvent/water, the catalyst amount and the role of promoters have been studied in detail. It was found that the acrylic acid space-time-yield as high as 764.6 mol AA/(mol Ni h) was obtained under the optimal experimental conditions. The Ni2O3 catalyst could be reused at least five times without obvious loss of activity. The characterization of recovered catalysts by XRD, XPS, SEM and TG–DTG revealed that the state of nickel remains unchanged during the reaction, and there are three types of soft coke deposited on the surface of the catalyst. The catalysts can be regenerated through calcination within 400 °C according to TG curve.

Background and aims Vascular peroxidase 1 (VPO1) plays a key role in mediation of cardiovascular oxidative injury. This study aims to determine whether VPO1 can promote programmed necrosis of endothelial cells and the underlying mechanisms. Methods and results Human umbilical vein endothelial cells (HUVECs) were incubated with oxidized low-density lipoprotein (ox-LDL, 100 μg/mL) for 48 h to induce cell injury, which showed an elevation in cell necrosis (reflected by the increased propidium iodide (PI) positive-staining cells, LDH release and decreased cell viability), concomitant with an increase in programmed necrosis-relevant proteins including receptor-interacting protein kinase 1/3 (RIPK1/3), p-RIPK3 and mixed lineage kinase domain like (MLKL); these phenomena were attenuated by necrostatin-1(Nec-1) and RIPK3 siRNA. Meanwhile, VPO1 was up-regulated in ox-LDL-treated endothelial cells accompanied by a decrease in GSK-3β activity and p-β-catenin levels, and an elevation of β-catenin levels; these phenomena were reversed in the presence of VPO1 siRNA or hypochlorous acid (HOCl) inhibitor; replacement of ox-LDL with HOCl could also induce endothelial programmed necrosis and activate the β-catenin signaling; β-catenin inhibitor could also suppress ox-LDL-induced RIPK-dependent necrosis. In hyperlipidemic patients, the plasma level of VPO1 was obviously increased concomitant with an elevation in plasma levels of RIPK1, RIPK3 and MLKL, and they were positively correlated. Conclusions VPO1 plays an important role in promotion of endothelial programmed necrosis under hyperlipidemic conditions through activation of β-catenin signaling. It may serve as a novel therapeutic target for prevention of endothelial dysfunction in hyperlipidemia.

The reactions of silver salts AgX [X = OTf (OTf = CF3SO3), ClO4 and BF4] and bis(diphenylphosphino)methane (dppm) with 4,4′-bipyridine (bipy) and its derivations [1,2-di(4-pyridyl)ethane (dpa), 1,2-di(4-pyridyl)ethylene (dpe), 1,3-bis(4-pyridyl)propane (bpp)] lead to six silver(I) complexes: {[Ag2(dppm)2(OTf)]2(μ-bipy)}(OTf)2·2CH3OH (1), {[Ag2(dppm)2(μ-bpp)(OTf)](OTf)·CH3OH}n (2), {[Ag2(dppm)2(CH3CN)]2(μ-dpa)}(ClO4)4·2CH3CN (3), [Ag2(dppm)3](ClO4)2 (4), {[Ag2(dppm)2(μ-bipy)(CH3CN)](BF4)2}n (5) and {[Ag2(dppm)2(μ-dpe)(CH3CN)](BF4)2}n (6). Complexes 1 and 3 are tetranuclear complexes with two eight-membered Ag2P4C2 rings bridged by bipy and dpa respectively. 2, 5 and 6 are of infinite chain structures formed by [Ag2(dppm)2] units linked by bpp, bipy and dpe respectively. 4 is a binuclear compound with two silver atoms bridged by three dppm ligands. All complexes are characterized by X-ray diffraction, fluorescence, 1H and 31P NMR spectroscopy and terahertz time-domain spectroscopy (THz-TDS).

A series of Ni-modified Y-zeolites with varying Ni loading in the presence of cupric salt as promoter were studied for acetylene hydrocarboxylation performed in a batch reactor. The catalysts were characterized by elemental analysis, H 2 -TPR, XRD, NH 3 -TPD, pyridine-FTIR, SEM, TG-DTG and Raman. It was found that the catalytic activity showed a pronounced dependence on the supports, metal introduction method, promoters and reaction conditions. The nickel species present as charge compensation cations in the zeolite framework constitute the active sites, and the acid sites help to promote the performance of carbonylation. Moreover, two types of coke were observed, and the remarkable reusability of NiY is attributable to the location of the coke outside the zeolite crystals. High catalytic performance was obtained over a NiY(7.0) catalyst with 62 g acrylic acid /(g cat. · h) of yield at 235 °C, 3.6 MPa of initial total pressure and 0.8 mM/l of cupric bromide within 40 min of reaction time. This is the most effective heterogeneous system for synthesizing acrylic acid by carbonylation of acetylene to date.

The imidazolium-based phosphoric ionic liquids, namely, N-methyl-N-methylimidazolium dimethyl phosphate ([Mmim]DMP), N-ethyl-N-methylimidazolium diethyl phosphate ([Emim]DEP) and N-butyl-N-methylimidazolium dibutyl phosphate ([Bmim]DBP), were prepared for removal of dimethyl disulfide (DMDS) from model oil through extractive desulfurization (EDS). The structures of the synthesized ionic liquids were systematically characterized and analyzed. Furthermore, the influences of various extraction parameters, for example, viscosities of ionic liquids, dosage and type of ionic liquids, reaction temperature, reaction time, and the reusability of ionic liquids, were studied. The experimental results showed that under the optimum extraction conditions the sulfur removal ability of the phosphoric ionic liquids followed the order of [Bmim]DBP ⩾ [Emim]DEP > [Mmim]DMP. It was also observed that the model oil was soluble in the ionic liquids, and the solubility of 12.9 mg(oil)/g(IL) was obtained for [Emim]DEP. In addition, the ionic liquids could easily be separated from the extraction mixture by simple decantation and could be reused at least five times after a reactivation treatment.

A series of the imidazolium-based phosphoric ionic liquids, N-methyl-N-methylimidazolium dimethyl phosphate ([Mmim]DMP), N-ethyl-N-methylimidazolium diethyl phosphate ([Emim]DEP), and N-butyl-N-methylimidazolium dibutyl phosphate ([Bmim]DBP), were synthesized and employed in the extraction and catalytic oxidation desulfurization system (ECODS) for the removal of 4,6-dimethyldienzothiophene (4,6-DMDBT) from a model oil, with hexaammonium heptamolybdate tetrahydrate ((NH4)6Mo7O24·4H2O) as catalyst and 30 wt % hydrogen peroxide (H2O2) solution as oxidant. The effects of the type of ionic liquid, amount of catalyst and H2O2, ILs/oil mass ratio, reaction time, reaction temperature, and regeneration of ionic liquid on the 4,6-DMDBT removal of a model oil were investigated in detail. The results indicate that a sulfur system containing H2O2, (NH4)6Mo7O24·4H2O, and [Bmim]DBP, exhibited such a high catalytic activity that the removal of 4,6-DMDBT could reach 89.2% at 50 °C in 3 h, which was markedly superior to me...