Effect of Polyethylene Pyrolysis Oil Hydrotreatment on the Pt/AlO Catalyst: Experimental Characterization.

The dramatic increase in plastics production, coupled with a low recycling and recovery rate, has been a major challenge for sustainable practices and combating climate change. Hydrotreatment processing to upgrade fuel oils is a well-known process in the petroleum industry. In this work, we aim to investigate the catalyst properties before and after the hydrotreatment of pyrolysis oil derived from plastics, namely, linear low-density polyethylene, as no such report is available in the literature.

A chromia-based sorbent for the enrichment of phosphotyrosine.

Developing of new core@shell particles (CSPs) bearing metal oxides on their outer surfaces is of a great interest. Such hybrid systems have many benefits, i.e.

Adsorption of Hexavalent Chromium and Divalent Lead Ions on the Nitrogen-Enriched Chitosan-Based Activated Carbon.

Optimizing the physicochemical properties of the chitosan-based activated carbon (Ch-ACs) can greatly enhance its performance toward heavy metal removal from contaminated water. Herein, Ch was converted into a high surface area (1556 m/g) and porous (0.69 cm/g) ACs with large content of nitrogen (~16 wt%) using KCO activator and urea as nitrogen-enrichment agents.

Na-Influenced Bulk and Surface Properties of the So-Called Iota(ι)-Alumina: Spectroscopy and Microscopy Studies.

The test alumina (the so-called ι-AlO) was thermally recovered at 1,100°C from chitosan-AlO hybrid films and found to contain Na and Ca impurity ions inherited from the parent chitosan. Two different modifications of pure alumina, namely, γ- and α-AlO, were adopted as control samples. The test and control aluminas were examined for 1) the bulk elemental constitution by atomic absorption spectroscopy (AAS), 2) the surface chemical composition by X-ray photoelectron spectroscopy (XPS), 3) the bulk phase composition by X-ray powder diffractometry (XRD), Fourier-transform infrared spectroscopy (IR), and Laser Raman (LRa) spectroscopy, 4) the surface area, topography, and morphology by N sorptiometry, and atomic force (AFM) and scanning electron microscopy (SEM), 5) the surface adsorptive interactions with pyridine and 2-propanol gas-phase molecules by IR spectroscopy of the adsorbed species, and 6) the surface catalytic interactions with 2-propanol gas-phase molecules by IR spectroscopy of the gas phase.

Aramid-Zirconia Nanocomposite Coating With Excellent Corrosion Protection of Stainless Steel in Saline Media.

Resistance to stainless steel corrosion in marine-based industries requires more research into materials with an improved surface and enhanced protection by utilizing surface coatings. Herein, a thermally stable aramid-zirconia nanocomposite has been successfully prepared using the sol-gel method to produce a zirconia network-structure bonded to the polymer chain. Using thermal gravimetric analysis (TGA), the residue mass of zirconia retained after the thermal degradation of aramid-zirconia film was determined and found to be 10% by mass.

Facile and Direct Preparation of Ultrastable Mesoporous Silica with Silver Nanoclusters: High Surface Area.

We report the successful direct synthesis of an ultrastable mesoporous silicon dioxide framework containing silver nanoclusters using a modified true liquid crystal templating method. Our modification produced an extraordinary material with a high average Brunauer-Emmett-Teller specific surface area of 1785 m g - the highest reported surface area to date - and an ultrastable mesoporous structure, which has been stable for nine years so far. This method eliminates the need for reduction of silver oxide into metallic silver and restricts the growth of silver clusters.

To what extent do polymeric stabilizers affect nanoparticles characteristics?

Colloidal synthesis of nanoparticles using polymeric stabilizers as a template of a structure directing agent provided a plethora of opportunities in fabricating nanoparticles (NPs) with controlled size, shape, composition and structural characteristics. To understand the complete potency of polymeric stabilizers during the synthesis of nanoparticles, the relationship between polymer characteristics such as structure, molecular weight and concentration and nanoparticles characteristics is discussed in depth. This review portrays the use of polymers to attain nanostructured materials via covalent and non-covalent approaches.

In-Situ Preparation of Aramid-Multiwalled CNT Nano-Composites: Morphology, Thermal Mechanical and Electric Properties.

In this work in-situ polymerization technique has been used to chemically link the functionalized multiwalled carbon nanotubes (CNTs) with aramid matrix chains. Phenylene diamine monomers were reacted in the first stage with the carboxylic acid functionalized CNTs and then amidized in-situ using terephthaloyl chloride generating chemically bonded CNTs with the matrix. Various proportions of the CNTs were used to prepare the hybrid materials.

Controlled Synthesis of ZrO Nanoparticles with Tailored Size, Morphology and Crystal Phases via Organic/Inorganic Hybrid Films.

In this investigation, well defined mesoporous zirconia nanoparticles (ZrO NPs) with cubic, tetragonal or monoclinic pure phase were synthesized via thermal recovery (in air) from chitosan (CS)- or polyvinyl alcohol (PVA)-ZrO hybrid films, prepared using sol-gel processing. This facile preparative method was found to lead to an almost quantitative recovery of the ZrOx content of the film in the form of ZrO NPs. Impacts of the thermal recovery temperature (450, 800 and 1100 °C) and polymer type (natural bio-waste CS or synthetic PVA) used in fabricating the organic/inorganic hybrid films on bulk and surface characteristics of the recovered NPs were probed by means of X-ray diffractometry and photoelectron spectroscopy, FT-IR and Laser Raman spectroscopy, transmission electron and atomic force microscopy, and N sorptiometry.

Non-noble, efficient catalyst of unsupported α-CrO nanoparticles for low temperature CO Oxidation.

Herein, we report the synthesis of chromium oxide nanoparticles, α -CrO NPs, followed by full characterization via XRD, SEM, XPS, and N sorptiometry. The synthesized nanoparticles were tested as catalysts toward the oxidation of CO. The impact of calcination temperature on the catalytic activity was also investigated.

In situ growth of ZnO nanoparticles in precursor-insensitive water-in-oil microemulsion as soft nanoreactors.

Zinc oxide (ZnO) nanostructures of uniform shapes and sizes (spherical, needle-like, and acicular) were directly synthesized using a relatively precursor-insensitive water-in-n-heptane microemulsion system stabilized by a mixture of cationic and non-ionic surfactants. With this colloidal system, the synthesized ZnO possesses the highest reported surface area (76 m(2) g(-1)) among the published reports utilizing other microemulsion systems. Such precursor insensitivity allowed studying the effect of Zn precursor:precipitating agent molar ratio (as high as 1:8) on the particle size, specific surface area, porosity, and morphology of the synthesized nanoparticles.

The efficient photocatalytic degradation of methyl tert-butyl ether under Pd/ZnO and visible light irradiation.

Methyl tert-butyl ether is a commonly used fuel oxygenate that is present in gasoline. It was introduced to eliminate the use of leaded gasoline and to improve the octane quality because it aids in the complete combustion of fuel by supplying oxygen during the combustion process. Over the past decade, the use of MTBE has increased tremendously worldwide.

Understanding the superior photocatalytic activity of noble metals modified titania under UV and visible light irradiation.

Although TiO2 is one of the most efficient photocatalysts, with the highest stability and the lowest cost, there are drawbacks that hinder its practical applications like its wide band gap and high recombination rate of the charge carriers. Consequently, many efforts were directed toward enhancing the photocatalytic activity of TiO2 and extending its response to the visible region. To head off these attempts, modification of TiO2 with noble metal nanoparticles (NMNPs) received considerable attention due to their role in accelerating the transfer of photoexcited electrons from TiO2 and also due to the surface plasmon resonance which induces the photocatalytic activity of TiO2 under visible light irradiation.

Preparation and characterization of Pd doped ceria-ZnO nanocomposite catalyst for methyl tert-butyl ether (MTBE) photodegradation.

A series of binary oxide catalysts (ceria-ZnO) were prepared and doped with different amounts of palladium in the range of 0.5%-1.5%.

FT-IR and 1H NMR studies of the state of solubilized water in water-in-oil microemulsions stabilized by mixtures of single- and double-tailed cationic surfactants.

The structure of solubilized water in water-in-n-heptane aggregates stabilized by mixtures of single- and double-tail quaternary ammonium surfactants, namely didodecyldimethylammonium chloride/dodecyltrimethylammonium chloride (DDAC/DTAC) or didodecyldimethylammonium bromide/dodecyltrimethylammonium bromide (DDAB/DTAB) was studied by two noninvasive techniques, (1)H NMR and FT-IR. In the former, the chemical shift data, δ(obs), were used to calculate the so-called deuterium/protium fractionation factor, φ(M), of the aggregate-solubilized water and were found to be unity. In the FT-IR study, upon increasing water/surfactant molar ratio, W, the frequency, ν(OD), of the HOD species decreases, while its full width at half height and its area increase.

Sonochemical synthesis and properties of nanoparticles of FeSbO4.

A sonochemical method was employed to prepare reactive nanoparticles of FeSbO(4) at 300 °C, which is the lowest calcination temperature reported so far for preparing FeSbO(4). A systematic evolution of the FeSbO(4) phase formation as a function of temperature was monitored by in situ synchrotron X-ray measurements. The 300 and 450 °C calcined powders exhibited specific surface areas of 116 and 75 m(2)/g, respectively.

Nanoparticles of antimony doped tin dioxide as a liquid petroleum gas sensor: effect of size on sensitivity.

The gas sensitivity exhibited by nanoparticles of 1 wt% Pd catalysed antimony doped tin dioxide (ATO) prepared by a citrate-nitrate process is reported here. The reduction of particle size to <3 nm, a dimension smaller than double the thickness of the charge depletion layer, has resulted in an exceptionally high butane sensitivity and selectivity. The sensitivity and selectivity of ATO particles of different sizes unequivocally proved that reducing the size of particles to below twice the Debye length dimension produces materials with exceptionally high sensitivity and selectivity for sensor applications.

Characterization of iron hydroxide/oxide nanoparticles prepared in microemulsions stabilized with cationic/non-ionic surfactant mixtures.

Iron oxide-hydroxide (α-Fe(2)O(3); Fe(OH)(3)) nanoparticles have been prepared by a microemulsion route using ammonia (NH(3)) solution or tetrabutylammonium hydroxide (TBAH) as precipitants. The iron oxide-hydroxide nanoparticles obtained were characterized by TGA, N(2) sorptiometry, XRD, IR, SEM, HR-TEM, and DLS techniques. Properties such as specific surface area (S(BET)), pore sizes and shapes, average particle size and distribution, crystallite structure, and thermal stability were determined.

Cerium oxide nanoparticles prepared in self-assembled systems.

This review concerns recent research on the synthesis of cerium oxide (also known as ceria, CeO(2)) in colloidal dispersions media for obtaining high surface area catalyst materials. Nanoparticles as small as 5 nm and surface area as high as 250 m(2)/g can be readily prepared by this method. Both normal micelles and water-in-oil microemulsions have been employed to directly precipitate nanoceria or other cerium precursors which can be converted into ceria by calcination.

Generation of metal oxide nanoparticles in optimised microemulsions.

The phase behavior and structure of aqueous-in-n-heptane microemulsions, stabilized by surfactant mixtures of di-n-didodecyldimethylammonium bromide, DDAB, and Brij(R)35 were studied by small angle (neutron or X-ray) scattering techniques. The aqueous nanodroplets contain either a precursor reactive salt or a precipitating agent, so that simple mixing induces nanoparticle formation. These formulated microemulsions display good phase stability against added polar additives such as monovalent, divalent, trivalent metal ions, ammonia solution, tetrabutylammonium hydroxide, and their mixtures.

Characterization of nano-cerias synthesized in microemulsions by N2 sorptiometry and electron microscopy.

A surfactant-stabilized microemulsion method was used to prepare nano-sized particles (<10 nm) of cubic-CeO2 exposing surfaces of not only highest specific areas (142-201 m(2)/g) ever reported for polycrystalline ceria, but also high thermal stability at 800 degrees C. Three different surfactants, a non-ionic, an anionic and a cationic, were used to form the microemulsions. Then, N2 sorptiometry and pore volume distribution calculations, were used to reveal microporous and mesoporous structures of these cerias as a function of surfactant type.

Microemulsion-based synthesis of CeO(2) powders with high surface area and high-temperature stabilities.

Pure ceria powders, CeO(2), were synthesized in heptane-microemulsified aqueous solutions of CeCl(3) or Ce(NO(3))(3) stabilized by AOT (sodium bis(2-ethylhexyl) sulfosuccinate), DDAB (di-n-didodecyldimethylammonium bromide), or DDAB + Brij 35 surfactant mixtures. Micellar DTAB (n-dodecyltrimethylammonium bromide) and vesicular DDAB systems were also used as media for generating CeO(2). Characterization of the powders by X-ray powder diffractometry, laser-Raman spectroscopy, and Fourier transform infrared spectroscopy revealed that in the presence of surfactants almost-agglomerate-free nanosized crystallites (6-13 nm) of anionic vacancy-free cubic CeO(2) were produced.