Ternary Ag/Magnesia-silica catalysts were tested in the direct synthesis of 1,3-butadiene from ethanol. The influence of the silver content and the type of silica source on catalytic performance has been studied. Prepared catalysts were characterized by (29) Si NMR, N2 sorption, small-angle X-ray scattering measurements, XRD, environmental scanning electron microscopy with energy dispersive X-ray analysis (ESEM/EDX), FTIR spectroscopy of adsorbed pyridine and CO2 , temperature-programmed desorption of CO2 and UV/Vis diffuse reflectance spectroscopy. Based on these characterization results, the catalytic performance of the catalysts in the 1,3-butadiene formation process was interpreted and a tentative model explaining the role of the different catalytically active sites was elaborated. The balance of the active sites is crucial to obtain an active and selective catalyst to form 1,3-butadiene from ethanol. The optimal silver loading is 1-2 wt% on a MgO-silica support with a molar Mg/Si ratio of 2. The silver species and basic sites (Mg−O pairs and basic OH groups) are of prime importance in the 1,3-butadiene production, catalyzing mainly the ethanol dehydrogenation and the aldol condensation, respectively.

Water splitting was performed in a photoelectrochemical cell (PEC) with water oxidation and hydrogen formation reactions in two separate compartments. A photoanode consisting of carbon paper loaded with TiO2 and a cathode made of Pt dispersed on carbon black spread also on carbon paper were fixed on both sides of a Nafion® membrane and electrically coupled via an external circuit. Anode and cathode compartments with serpentine flow field were operated either in the liquid or vapour phase. Electrical current was monitored with chronoamperometry and D2 formation from deuterated water using mass spectrometry. Mapping the photocurrent under a variety of reaction conditions enabled identification of the limiting factors related to proton and photocarrier transport and reaction product evacuation. This comprehensive research approach to the operation of a PEC will assist future optimisation of cell design and development of membrane electrode assemblies.

AimsThis study aimed to investigate the effects of nanomaterial (NM) exposure on DNA methylation.Methods and ResultsIntra-tracheal administration of NM: gold nanoparticles (AuNPs) of 5-, 60- and 250-nm diameter; single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) at high dose of 2.5 mg/kg and low dose of 0.25 mg/kg for 48 h to BALB/c mice. Study showed deregulations in immune pathways in NM-induced toxicity in vivo. NM administration had the following DNA methylation effects: AuNP 60 nm induced CpG hypermethylation in Atm, Cdk and Gsr genes and hypomethylation in Gpx; Gsr and Trp53 showed changes in methylation between low- and high-dose AuNP, 60 and 250 nm respectively, and AuNP had size effects on methylation for Trp53.ConclusionEpigenetics may be implicated in NM-induced disease pathways.

A new ordered mesoporous silica material (COK-19) with cubic symmetry is synthesized by silicate polycondensation in a citric acid/citrate buffered micellar solution of Pluronic F127 triblock copolymer near neutral pH. SAXS, nitrogen adsorption, TEM, and electron tomography reveal the final material has a cubic close packed symmetry (Fm3̅m) with isolated spherical mesopores interconnected through micropores. Heating of the synthesis medium from room temperature to 70 °C results in a mesopore size increase from 7.0 to 11.2 nm. Stepwise addition of the silicate source allows isolation of a sequence of intermediates that upon characterization with small-angle X-ray scattering uncovers the formation process via formation and aggregation of individual silica-covered Pluronic micelles.

EU-7 zeolite with Si/Al ratio of 15 is identified as a BIK type zeolite. The framework charge is compensated with Cs+ cations located in 8-ring channels at regular distances. Even partially exchanged, Cu-loaded EU-7 is active in NH3-SCR and withstands hydrothermal aging at 900 °C needed for application in diesel particulate filters.