Deep dive into the chronic toxicity of tyre particle mixtures and their leachates.

Particles from the tread of vehicle tyres are a global pollutant, which are emitted into the environment at an approximate rate of 1.4 kg.year for an average passenger-car.

Translocation of C-polystyrene nanoplastics into fish during a very-low concentration dietary exposure.

Assessing the dietary accumulation of nanoplastics in animals following very-low exposure concentrations is restricted due to analytical limitations. This study adapted a method for synthesising semi-stable C-PS NPs (through styrene polymerisation) in small volumes for deployment in environmental studies. The method was developed with non-labelled material where the final polystyrene product had a primary particle size of 35 ± 8 nm (as measured by transmission electron microscopy).

Metal-Acid Synergy: Hydrodeoxygenation of Anisole over Pt/Al-SBA-15.

Invited for this month's cover is the group of Karen Wilson and Adam Lee at RMIT University. The image shows platinum nanoparticles and Brønsted acid sites working cooperatively to catalyse the efficient hydrodeoxygenation of phenolic lignin residues to produce sustainable biofuels. The Full Paper itself is available at 10.

Metal-Acid Synergy: Hydrodeoxygenation of Anisole over Pt/Al-SBA-15.

Hydrodeoxygenation (HDO) is a promising technology to upgrade fast pyrolysis bio-oils but it requires active and selective catalysts. Here we explore the synergy between the metal and acid sites in the HDO of anisole, a model pyrolysis bio-oil compound, over mono- and bi-functional Pt/(Al)-SBA-15 catalysts. Ring hydrogenation of anisole to methoxycyclohexane occurs over metal sites and is structure sensitive; it is favored over small (4 nm) Pt nanoparticles, which confer a turnover frequency (TOF) of approximately 2000 h and a methoxycyclohexane selectivity of approximately 90 % at 200 °C and 20 bar H ; in contrast, the formation of benzene and the desired cyclohexane product appears to be structure insensitive.

Tunable Silver-Functionalized Porous Frameworks for Antibacterial Applications.

Healthcare-associated infections and the rise of drug-resistant bacteria pose significant challenges to existing antibiotic therapies. Silver nanocomposites are a promising solution to the current crisis, however their therapeutic application requires improved understanding of underpinning structure-function relationships. A family of chemically and structurally modified mesoporous SBA-15 silicas were synthesized as porous host matrices to tune the physicochemical properties of silver nanoparticles.

Impact of Macroporosity on Catalytic Upgrading of Fast Pyrolysis Bio-Oil by Esterification over Silica Sulfonic Acids.

Fast pyrolysis bio-oils possess unfavorable physicochemical properties and poor stability, in large part, owing to the presence of carboxylic acids, which hinders their use as biofuels. Catalytic esterification offers an atom- and energy-efficient route to upgrade pyrolysis bio-oils. Propyl sulfonic acid (PrSO H) silicas are active for carboxylic acid esterification but suffer mass-transport limitations for bulky substrates.

Acetic Acid Ketonization over FeO/SiO for Pyrolysis Bio-Oil Upgrading.

A family of silica-supported, magnetite nanoparticle catalysts was synthesised and investigated for continuous-flow acetic acid ketonisation as a model pyrolysis bio-oil upgrading reaction. The physico-chemical properties of FeO/SiO catalysts were characterised by using high-resolution transmission electron microscopy, X-ray absorption spectroscopy, X-ray photo-electron spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy, thermogravimetric analysis and porosimetry. The acid site densities were inversely proportional to the FeO particle size, although the acid strength and Lewis character were size-invariant, and correlated with the specific activity for the vapour-phase acetic ketonisation to acetone.

Selectivity control in Pt-catalyzed cinnamaldehyde hydrogenation.

Chemoselectivity is a cornerstone of catalysis, permitting the targeted modification of specific functional groups within complex starting materials. Here we elucidate key structural and electronic factors controlling the liquid phase hydrogenation of cinnamaldehyde and related benzylic aldehydes over Pt nanoparticles. Mechanistic insight from kinetic mapping reveals cinnamaldehyde hydrogenation is structure-insensitive over metallic platinum, proceeding with a common Turnover Frequency independent of precursor, particle size or support architecture.

Tunable Pt nanocatalysts for the aerobic selox of cinnamyl alcohol.

The selective aerobic oxidation of cinnamyl alcohol over Pt nanoparticles has been tuned via the use of mesoporous silica supports to control their dispersion and oxidation state. High area two-dimensional SBA-15, and three-dimensional, interconnected KIT-6 silica significantly enhance Pt dispersion, and thus surface PtO2 concentration, over that achievable via commercial low surface area silica. Selective oxidation activity scales with Pt dispersion in the order KIT-6 ≥ SBA-15 > SiO2, evidencing surface PtO2 as the active site for cinnamyl alcohol selox to cinnamaldehyde.