Carboxymethyl β-Cyclodextrin Assistance for the 4-Nitrophenol Reduction Using Cobalt-Based Layered Double Hydroxides.

Cobalt-aluminum-layered double hydroxides containing carboxymethyl β-cyclodextrin (CMβCD) were synthesized by coprecipitation and evaluated as a cobalt source for the 4-nitrophenol reduction in an aqueous medium. Several physicochemical techniques (XRD, FTIR, TGA) indicated the intercalation of the anionic cyclodextrin without damages to the hydrotalcite-type structure. These lamellar cobalt-aluminum hybrid materials (CoAl_CMβCD) were evaluated in the 4-nitrophenol reduction and showed higher activities in comparison with the CMβCD-free standard material (CoAl_CO).

Synthesis of Gold Nanoparticles over CoAl Mixed Oxide for Ethanol Oxidation Reaction.

Catalytic total oxidation is an effective technique for the treatment of industrial VOCs principally resulting from industrial processes using solvents and usually containing mono-aromatics (BTEX) and oxygenated compounds (acetone, ethanol, butanone). The aim of this work is to deposit gold nanoparticles on CoAl mixed oxide issued from layered double hydroxide (LDH) precursor by using the deposition precipitation (DP) method, which is applied with two modifications, labeled method (A) and method (B), in order to enhance the interaction of the HAuCl precursor with the support. Method (A) involves the hydrolysis of the HAuCl precursor after addition of the support, while in method (B), the gold precursor is hydrolyzed before adding the support.

Potentiometric Chemical Sensors Based on Metal Halide Doped Chalcogenide Glasses for Sodium Detection.

Chalcogenide glasses are widely used as sensitive membranes in the chemical sensors for heavy metal ions detection. The lack of research work on sodium ion-selective electrodes (Na-ISEs) based on chalcogenide glasses is due to the high hygroscopicity of alkali dopes chalcogenides. However, sodium halide doped GaS-GeS glasses are more chemically stable in water and could be used as Na-sensitive membranes for the ISEs.

Investigation of catalysts M/CeO (M = Pt, Rh, or Pd) for purification of CO derived from oxycombustion in the absence or presence of water.

Oxyfuel combustion is a promising technology to produce a CO-rich flue gas ready suitable for sequestration or valorization. But its storage as well as its further valorization requires to increase the CO purification as a small amount of CO and NOx are produced during combustion. Based on the technology developed for three-way converters, similar systems, i.

Mixed Oxides Issued from Hydrotalcite Precursors for Toluene and CO Total Oxidation: Comparison of Preparation Method.

Catalytic total oxidation is an effective technique for the treatment of industrial VOCs. This emission is generally accompanied by the presence of other products like CO, NO or other VOC. In this paper, the development of catalysts for the total oxidation of CO and toluene mixture is performed.

In vitro toxicological evaluation of emissions from catalytic oxidation removal of industrial VOCs by air/liquid interface (ALI) exposure system in repeated mode.

Toxicity of toluene and by-products formed during its catalytic oxidative degradation was studied in human bronchial BEAS-2B cells repeatedly exposed. BEAS-2B cells were exposed using an Air-Liquid Interface (ALI) System (Vitrocell®) for 1 h per day during 1, 3 or 5 days to gaseous flows: toluene vapors (100 and 1000 ppm) and outflow after catalytic oxidation of toluene (10 and 100%). After exposure to gaseous flow, cytotoxicity, inflammatory response and Xenobiotic Metabolism Enzymes (XME) gene expression were investigated.

Usefulness of toxicological validation of VOCs catalytic degradation by air-liquid interface exposure system.

Toluene is one of the most used Volatile Organic Compounds (VOCs) in the industry despite its major health impacts. Catalytic oxidation represents an efficient remediation technique in order to reduce its emission directly at the source, but it can release by-products. To complete the classical performance assessment using dedicated analytical chemistry methods, we propose to perform an untargeted toxicological validation on two efficient catalysts.

Catalytic oxidation of propylene, toluene, carbon monoxide, and carbon black over Au/CeO₂ solids: comparing the impregnation and the deposition-precipitation methods.

Au/CeO₂ solids were prepared by two methods: deposition-precipitation (DP) and impregnation (Imp). The prepared solids were calcined under air at 400°C. Both types of catalysts have been tested in the total oxidation of propylene, toluene, carbon monoxide, and carbon black.

Noble-metal-based catalysts supported on zeolites and macro-mesoporous metal oxide supports for the total oxidation of volatile organic compounds.

The use of porous materials to eliminate volatile organic compounds (VOCs) has proven very effective towards achieving sustainability and environmental protection goals. The activity of zeolites and macro-mesoporous metal-oxide supports in the total oxidation of VOCs has been investigated, with and without noble-metal deposition, to develop highly active catalyst systems where the formation of by-products was minimal. The first catalysts employed were zeolites, which offered a good activity in the oxidation of VOCs, but were rapidly deactivated by coke deposition.