We report a simple and effective method for the preparation of high-density and aligned carbon nanotube (CNT) membranes. The CNT arrays were prepared by water-assisted chemical vapor deposition (CVD) and were subsequently pushed over and stacked into dense membranes by mechanical rolling. It was demonstrated that various gases and liquids, including H2, He, N2, O2, Ar, water, ethanol, hexane, a...

Nature has developed an impressive repertoire of metal-based enzymes that perform complex chemical reactions under moderate conditions. Catalysts that produce molecular hydrogen (H2) are particularly promising for renewable energy applications. Unfortunately, natural and chemical H2-catalysts are often irreversibly degraded by molecular oxygen (O2). Here we present a straightforward procedure b...

A Hollow-fiber Membrane Biofilm Reactor (MBfR) was used to nitrify and denitrify synthetic wastewater to remove nitrogenous pollutants such as ammonium, nitrate, and nitrite. Aerobic and anoxic MBfRs were combined to oxidize and reduce these nitrogenous pollutions using biofilms as the catalyst for these chemical reactions. The MBfR is capable of converting ammonium (NH4) to nitrogen gas (N2), ...

In this study, oxidative discoloration of Basic blue3 (B.B3) and Disperse blue56 (D.B56) dyes in synthetic textile wastewater has been studied using Fenton (Fe2+/H2 O2 ) process. The Fenton’s technique showed satisfactory color removal efficiency. The operating parameters such as concentration of Fe2+, dose of H2 O2 , initial concentration of dye, time contact, initial volume of wastewater that...

The article is devoted to the analysis of flame anchoring mechanism in test case MASCOTTE C-60 RCM2 on supercritical hydrogen/oxygen combustion at 60 bar, with transcritical (liquid) injection oxygen. simulated by means in-house parallel code HeaRT three-dimensional LES framework. cubic Peng–Robinson equation state its improved translated volume formulation assumed. Diffusive mechanisms and tra...

We report on a computational investigation of the passive transport of H2 and O2 between the external solution and the hydrogen-producing active site of CpI [FeFe]-hydrogenase from Clostridium pasteurianum. Two distinct methodologies for studying gas access are discussed and applied: (1) temperature-controlled locally enhanced sampling, and (2) volumetric solvent accessibility maps, providing c...

Recently, H2O2 is drawing growing interest in green chemistry 15 because it acts as direct and environmental benign oxidant in organic synthesis [2] and because its high cost limits the use for the production of bulk organic chemicals. The synthesis of hydrogen peroxide by direct reaction between H2 and O2 is a very attractive alternative to traditional anthraquinone 20 process. Direct synthesi...

Treatment under H2 at 300 °C of Ru(COD)(COT) dispersed on silica yields 2 nm ruthenium nanoparticles, [Rup/SiO2], according to EXAFS, HRTEM and XPS. H2 adsorption measurements on [Rup/SiO2] in the absence of O2 show that Ru particles adsorb up to ca. 2 H per surface ruthenium atoms (2H/Rus) on various samples; this technique can therefore be used to measure the dispersion of Ru particles. In co...

Ion-molecule reactions between clusters of H2/D2 and O2 in liquid helium nanodroplets were initiated by electron-induced ionization (at 70 eV). Reaction products were detected by mass spectrometry and can be explained by a primary reaction channel involving proton transfer from H3(+) or H3(+)(H2)n clusters and their deuterated equivalents. Very little HO2(+) is seen from the reaction of H3(+) w...

We used a novel amperometric microsensor for measuring hydrogen gas production and consumption at high spatio-temporal resolution in cyanobacterial biofilms and mats dominated by non-heterocystous filamentous cyanobacteria (Microcoleus chtonoplastes and Oscillatoria sp.). The new microsensor is based on the use of an organic electrolyte and a stable internal reference system and can be equipped...