Methanol promoted naphtha catalytic pyrolysis to light olefins on Zn-modified high-silicon HZSM-5 zeolite catalysts.

The methanol promoted naphtha catalytic pyrolysis system to obtain light olefins (ethylene and propylene) was studied over Zn-modified high-silicon HZSM-5 (Zn/HZSM-5) catalysts. Compared with the individual naphtha catalytic pyrolysis to light olefins, the addition of methanol remarkably improved the naphtha conversion and the yield of the light olefins. All Zn/HZSM-5 samples were characterized by using a variety of techniques including inductively coupled plasma-optical emission spectrometry (ICP-OES), X-ray diffraction (XRD), scanning electron microscopy (SEM), N adsorption, NH-temperature programmed desorption (NH-TPD), X-ray photoelectron spectroscopy (XPS), pyridine adsorption infrared spectroscopy (Py-IR), and Fourier transform infrared spectroscopy (FT-IR).

Vanadium silicate (EVS)-supported silver nanoparticles: A novel catalytic sorbent for elemental mercury removal from flue gas.

Vanadium silicate (EVS) is a vanadium-substituted form of titanosilicate that has a high potential for use as a sorbent for mercury removal. In the present study, EVS with supported silver nanoparticles (EVS-Ag100) as the catalytic sorbent was synthesized for elemental mercury (Hg°) capture. The physical and chemical properties of the sorbents were investigated.

[Determination of the key impurity in caprolactam produced from a combined process by gas chromatography-mass spectroscopy].

Caprolactam (CPL) is an important chemical raw material. Because even trace level contaminations in CPL can directly influence the polymerization and the resulting properties of fibers, the CPL monomer must be very pure. In this study, gas chromatography with a flame ionization detector (GC/FID) and gas chromatography mass spectroscopy (GC-MS) techniques were developed to determinate the key impurities in CPL using a novel process which characterized the ultraviolet (UV) absorption rates of the samples.

[Qualitative detection and source analysis of the organic chlorides in the byproducts of biodiesel prepared using swill-cooked dirty oil under sub-critical conditions].

This paper introduces a gas chromatography-mass spectrometry (GC-MS) qualitative detection method for organic chlorides in crude glycerol and distillated light components, which are the byproducts of biodiesel. Samples with a higher total chlorine content were obtained from the transesterification reaction between swill-cooked dirty oil and methanol under subcritical conditions. Before GC-MS analysis, -hexane extraction was performed to remove the soluble lipid interfering components, such as methyl fatty acid ester and free fatty acids, from the samples.

[Qualitative analysis of compositions of anthraquinone series working solution by gas chromatography-mass spectrometry].

A method for the qualitative analysis of compositions of anthraquinone working solution (WS)/hydrogenated working solution (HWS) by gas chromatography-mass spectrometry (GC-MS) was developed. The composition of ethylanthraquinone (eAQ) WS/HWS was identified by GC-MS. Then the samples of amylanthraquinone (AAQ) WS/HWS were analyzed by GC-MS.

Comparison of electrochemical performance of LiNi Co O cathode materials synthesized from coated (1-)Ni(OH)@Co(OH) and doped Ni Co (OH) precursors.

LiNi Co O cathode materials were successfully synthesized from coated (1-)Ni(OH)@Co(OH) and doped Ni Co (OH) precursors, and the effects of the Co site and content in the precursor and final cathode material on the structure, morphology, and electrochemical performance of the cathodes were investigated using X-ray diffraction, scanning electron microscopy, and charge-discharge tests. The electrochemical performance of the materials prepared from the coated precursor was generally better than that of the materials prepared from the doped precursor. However, with increasing Co content, the performance difference gradually decreased.

Theoretical Study of As₂O₃ Adsorption Mechanisms on CaO surface.

Emission of hazardous trace elements, especially arsenic from fossil fuel combustion, have become a major concern. Under an oxidizing atmosphere, most of the arsenic converts to gaseous As₂O₃. CaO has been proven effective in capturing As₂O₃.

Protective desilication of highly siliceous H-ZSM-5 by sole tetraethylammonium hydroxide for the methanol to propylene (MTP) reaction.

Protective desilication of highly siliceous H-ZSM-5 was effectively realized by dissolution and recrystallization in tetraethylammonium hydroxide (TEAOH) solution. With better balance between dissolution of OH and recrystallization of TEA, intracrystalline mesopores could be generated by selective dissolution of Si by the drilling effects of TEAOH on the micropores, and then Si species in the mother liquor near the external surface could be recrystallized into ZSM-5 shell. With a significantly reduced diffusion length provided by the intracrystalline mesopores, TEAOH-treated samples exhibited longer lifetime and higher propylene selectivity than the parent H-ZSM-5 zeolite.

Porous Graphene-Confined Fe-K as Highly Efficient Catalyst for CO Direct Hydrogenation to Light Olefins.

We devised iron-based catalysts with honeycomb-structured graphene (HSG) as the support and potassium as the promoter for CO direct hydrogenation to light olefins (CO-FTO). Over the optimal FeK1.5/HSG catalyst, the iron time yield of light olefins amounted to 73 μmol g s with high selectivity of 59%.

Selectivity Control on Hydrogenation of Substituted Nitroarenes through End-On Adsorption of Reactants in Zeolite-Encapsulated Platinum Nanoparticles.

Platinum nanoparticles encapsulated into zeolite Y (Pt@Y catalyst) exhibit excellent catalytic selectivity in the hydrogenation of substituted nitroarenes to form the corresponding aromatic amines, even after complete conversion. With the hydrogenation of p-chloronitrobenzene as a model, the role of zeolite encapsulation toward perfect selectivity can be attributed to constraint of the substrate adsorbed on the platinum surface in an end-on conformation. This conformation results in the activation of only one adsorbed group, with little influence on the other one in the molecule.

Polybrominated diphenyl ethers (PBDEs) in water, surface sediment, and suspended particulate matter from the Yellow River, China: Levels, spatial and seasonal distribution, and source contribution.

Fourteen polybrominated diphenyl ether (PBDE) congeners were measured in water, suspended particulate matter (SPM), and sediment samples collected from the entire expanse of the Yellow River in dry and wet seasons. Higher concentrations of PBDEs were found in the middle and lower reaches of the river compared with those in the upper reaches, ascribed to the relatively developed and urbanized cities located in the areas near the middle and lower reaches. The PBDE concentrations in the samples collected during the dry season were lower than those in the samples collected during the wet season because of thaw and rainfall.

Rigid TiO coated mesoporous hollow Si nanospheres with high structure stability for lithium-ion battery anodes.

Rigid oxygen-deficient TiO coated mesoporous hollow Si nanospheres with a mechanically and electrically robust structure have been constructed through a facile method for high-performance Li-ion battery anodes. The mesoporous hollow structure provides enough inner void space for the expansion of Si. The oxygen-deficient TiO coating has functions in three aspects: (1) avoiding direct contact between Si and the electrolyte; (2) suppressing the outward expansion of the mesoporous hollow Si nanospheres; (3) improving the conductivity of the composite.

An Efficient Metal-Free Catalyst for Oxidative Dehydrogenation Reaction: Activated Carbon Decorated with Few-Layer Graphene.

Activated carbon (AC) has been widely used in the catalysis field because of its low cost, scalable production, high specific surface area, and abundant exposed edge. Because of the amorphous structure, traditional AC is unstable in presence of O at high temperature, which hinders the application of AC catalysts in oxidative dehydrogenation (ODH) of alkanes. Here, partially graphitic AC decorated with few-layer graphene is facilely fabricated by simple high-temperature calcination.

Graphene-based nanomaterials for drug and/or gene delivery, bioimaging, and tissue engineering.

Here, we discuss the biomedical applications of graphene-based nanomaterials (GBNs). We examine graphene and its various derivatives, including graphene, graphene oxides (GOs), reduced graphene oxides (rGOs), graphene quantum dots (GQDs), and graphene composites, and discuss their unique properties related to their biomedical applications. We also summarize the detailed biomedical applications of GBNs, including drug and/or gene delivery, bioimaging, and tissue engineering.

Synthesis of Renewable Lubricant Alkanes from Biomass-Derived Platform Chemicals.

The catalytic synthesis of liquid alkanes from renewable biomass has received tremendous attention in recent years. However, bio-based platform chemicals have not to date been exploited for the synthesis of highly branched lubricant alkanes, which are currently produced by hydrocracking and hydroisomerization of long-chain n-paraffins. A selective catalytic synthetic route has been developed for the production of highly branched C alkanes as lubricant base oil components from biomass-derived furfural and acetone through a sequential four-step process, including aldol condensation of furfural with acetone to produce a C double adduct, selective hydrogenation of the adduct to a C ketone, followed by a second condensation of the C ketone with furfural to generate a C aldol adduct, and finally hydrodeoxygenation to give highly branched C alkanes in 50.

Surfactants assist in lipid extraction from wet Nannochloropsis sp.

An efficient approach involving surfactant treatment, or the modification and utilization of surfactants that naturally occur in algae (algal-based surfactants), was developed to assist in the extraction of lipids from wet algae. Surfactants were found to be able to completely replace polar organic solvents in the extraction process. The highest yield of algal lipids extracted by hexane and algal-based surfactants was 78.

Utilization of biodiesel by-product as substrate for high-production of β-farnesene via relatively balanced mevalonate pathway in Escherichia coli.

Farnesene has been identified as suitable jet fuel substitutes and metabolic engineering for microbial production of farnesene is an alternative and attractive route. In this study, due to accumulation of toxic intermediate isopentenyl pyrophosphate (IPP), an engineered Escherichia coli strain harboring heterologous mevalonate pathway produced only 4.11mg/L β-farnesene.

Deuterated Ethanol as a Probe for Measuring Equilibrium Isotope Effects for Hydroxyl Exchange.

Equilibrium deuterium isotope effects for exchange of hydroxyl deuterons and protons among tert-butanol, phenol, ethanethiol, diethylamine, and ethanol were measured by using NMR and also calculated theoretically. Deuterated ethanol could be used as a probe for measuring equilibrium isotope effects (EIE) for hydroxyl exchange; tert-butanol, phenol, ethanethiol, diethylamine, and pyrrole were used as five representive examples. A procedure called the "one-atom isotope effect" was used to save time in the calculations.

A Facile and Efficient Method to Fabricate Highly Selective Nanocarbon Catalysts for Oxidative Dehydrogenation.

Carbon nanotubes (CNTs) were used in oxidative dehydrogenation (ODH) reactions. Quinone groups on the CNT surface were identified as active sites for the dehydrogenation pathway. Liquid-phase oxidation with HNO is one way to generate various oxygen functionalities on the CNT surface but it produces a large amount of acid waste, limiting its industrial application.

The Acceptor Side of Photosystem II Is the Initial Target of Nitrite Stress in Synechocystis sp. Strain PCC 6803.

Nitrite, a common form of inorganic nitrogen (N), can be used as a nitrogen source through N assimilation. However, high levels of nitrite depress photosynthesis in various organisms. In this study, we investigated which components of the photosynthetic electron transfer chain are targeted by nitrite stress in Synechocystis sp.

Selective One-Pot Production of High-Grade Diesel-Range Alkanes from Furfural and 2-Methylfuran over Pd/NbOPO.

A one-pot method for the selective production of high-grade diesel-range alkanes from biomass-derived furfural and 2-methylfuran (2-MF) was developed by combining the hydroxyalkylation/alkylation (HAA) condensation of furfural with 2-MF and the subsequent hydrodeoxygenation (HDO) over a multifunctional Pd/NbOPO catalyst. The effects of various reaction conditions as well as a variety of solid-acid catalysts and metal-loaded NbOPO catalysts were systematically investigated to optimize the reaction conditions for both reactions. Under the optimal reaction conditions up to 89.

Aqueous enzymatic process for cell wall degradation and lipid extraction from Nannochloropsis sp.

An effective cell disruption method, including alkaline pretreatment and subsequent enzymatic treatment, was established to break cell walls and extract lipid from Nannochloropsis sp. A synergistic effect was found between alkaline pretreatment and enzymatic treatment. The combination of commercialize enzymes (cellulase, protease, lysozyme, and pectinase) achieved higher lipid yield compared with a single enzyme application.

Synthesis of High-Quality Large-Area Homogenous 1T' MoTe from Chemical Vapor Deposition.

High-quality large-area few-layer 1T' MoTe films with high homogeneity are synthesized by the controlled tellurization of MoO film. The Mo precursor plays a key role in determining the quality and morphology of the 1T' MoTe . Furthermore, the amount of Te strongly influences the phase of the MoTe .

Nitrogen Chemistry and Coke Transformation of FCC Coked Catalyst during the Regeneration Process.

Regeneration of the coked catalyst is an important process of fluid catalytic cracking (FCC) in petroleum refining, however, this process will emit environmentally harmful gases such as nitrogen and carbon oxides. Transformation of N and C containing compounds in industrial FCC coke under thermal decomposition was investigated via TPD and TPO to examine the evolved gaseous species and TGA, NMR and XPS to analyse the residual coke fraction. Two distinct regions of gas evolution are observed during TPD for the first time, and they arise from decomposition of aliphatic carbons and aromatic carbons.

Improved Productivity of Neutral Lipids in Chlorella sp. A2 by Minimal Nitrogen Supply.

Nitrogen starvation is an efficient environmental pressure for increasing lipid accumulation in microalgae, but it could also significantly lower the biomass productivity, resulting in lower lipid productivity. In this study, green alga Chlorella sp. A2 was cultivated by using a minimal nitrogen supply strategy under both laboratory and outdoor cultivation conditions to evaluate biomass accumulation and lipid production.