Non-thermal plasma abatement of trichloroethylene with DC corona discharges

The decomposition of trichloroethylene (TCE) in air by non-thermal plasma was investigated with a multi-pin-to-plate direct current (DC) discharge at atmospheric pressure and room temperature. The effects of various operating parameters on the removal efficiency (RE) were examined. The experiments indicated that for low energy densities higher removal could be obtained with positive corona. For negative corona and 10 % relative humidity (RH) a maximum RE of 99.5 % could be achieved at 1100 J L-1. Formation of by-products was qualitatively analyzed in detail with FT-IR spectroscopy and mass spectrometry. Detected by-products for negative corona operated at 300 J L-1 and 10 % RH include dichloroacetylchloride, trichloroacetaldehyde, phosgene, ozone, HCl, Cl2, CO and CO2. The highest RE for TCE was achieved with a relative humidity of 19 %

Oscillatory behavior of Pd-Au catalysts in toluene total oxidation

In this work, the activity of bimetallic Pd-Au doped hierarchically structured titania catalysts has been investigated in the total oxidation of toluene. In earlier works, doping titania with group Vb metal oxides ensured an increased catalytic performance in the elimination of VOC molecules. A synergy between gold and palladium loaded at the surface of titania supports provided better performances in VOC oxidation reactions. Therefore, the main focus in this work was to investigate the durability of the prepared catalysts under long time-on-stream periods. Vanadium-doped catalysts showed a stable activity throughout the whole 110 h test, whereas, surprisingly, niobium-doped catalysts presented a cycle-like activity while nevertheless maintaining a high performance in toluene elimination. Operando Diffuse Reflectance Infrared Fourrier Transform spectroscopy (DRIFT) experiments revealed that variations in the presence of OH radicals and the presence of carbonaceous compounds adsorbed at the surface of spent catalysts varies with the occurrence of oscillations. X-ray Photoelectron Spectroscopy (XPS) results show that interactions between the material and the active phase provided extra amounts of mobile oxygen species and participated in easing the reduction of palladium. An enhanced redox reaction scheme is thus obtained and allows the occurrence of the cyclic-like performance of the catalyst

Top 10 Cited Papers in the Section “Environmental Catalysis”

This editorial examines the 10 most cited articles of 2018–2019 published in the “Environmental Catalysis” section of the Catalysts journal [...

Catalytic Removal of Volatile Organic Compounds

The degradation of air quality by the release of volatile organic compounds (VOCs) into the air particularly harms human health and our environment. [...

Catalytic Removal of Volatile Organic Compounds

The degradation of air quality by the release of volatile organic compounds (VOCs) into the air particularly harms human health and our environment. [...

Feature Papers to Celebrate “Environmental Catalysis”—Trends & Outlook

This Special Issue collects three reviews, eight articles, and two communications related to the design of catalysts for environmental applications, such as the transformation of several pollutants into harmless or valuable products [...

Contribution à la mise au point de nouveaux catalyseurs pour la destruction de COVs aromatiques et chlorés.

communication orale donnée lors du 2ème Worshop nord-européen "Récupération et traitement des rejets industriels de COVs " 23 juin 2006 à Len

Oxydation catalytique du formaldéhyde sur des matériaux mésoporeux à base de manganèse

La qualité de l'air intérieur est une préoccupation majeure de notre société. Le formaldéhyde (HCHO) est un polluant atmosphérique important et présent dans divers environnements intérieurs comme la maison, le bureau et l'industrie. L'oxydation catalytique complète du formaldéhyde est une voie prometteuse pour convertir ce polluant en produits inoffensifs. Les catalyseurs à base d oxydes de métaux de transition sont décrits comme les plus prometteurs. Parmi ces oxydes, ceux à base d'oxydes de manganèse sont peu coûteux, non toxiques et peuvent être efficaces pour convertir le formaldéhyde à basse température. Ce travail vise à développer des catalyseurs mésoporeux à base d'oxydes de manganèse pour l'élimination catalytique à basse température du formaldéhyde. Des oxydes de manganèse mésoporeux contenant des teneurs variables en cérium ont tout d abord été obtenus par activation chimique (traitement acide). L'optimisation de la synthèse du matériau mésoporeux sous atmosphère contrôlée a ensuite conduit à l obtention d une mésostructure lamellaire d oxyde de manganèse. Le délaminage de cet oxyde, après calcination, a produit un oxyde de manganèse ayant des propriétés texturales très intéressantes et redox grandement améliorées. Le catalyseur le plus actif a pu oxyder complètement HCOH en CO2 et H2O à 110 C. Finalement, des hydrotalcites à base de Mg, Mn et Al, activées par ultrasons, ont été synthétisées pour être employées en tant que précurseurs d oxydes mixtes de manganèse de grandes surfaces spécifiques. L'effet de l apport des ultrasons et de la composition en éléments du matériau (Mg/Mn) sur les propriétés structurales, texturales, basiques et catalytiques des oxydes mixtes a plus particulièrement été étudié.Indoor air quality is currently a societal concern. Formaldehyde is an important air pollutant in various indoor environments, including houses, offices and industries. The catalytic complete oxidation of formaldehyde is a promising way to convert this pollutant into harmless products. Transition metal oxides based catalysts are described as the most promising catalysts. Among these oxides, manganese oxide based materials are promising, cheap, non-toxic and effective catalysts to convert formaldehyde at low temperature. The present work aims to develop a novel mesoporous manganese oxide based catalyst for low temperature formaldehyde catalytic removal. Mesoporous manganese oxides containing variable amounts of cerium were first obtained by chemical activation (acid treatment). The optimization in the synthesis of mesoporous manganese oxide under controlled atmosphere produces a layered mesostructure manganese oxide. The delamination of this layered mesostructure oxide, after calcination, produces high surface area manganese oxides with improved redox properties and the most active catalyst completely oxidizes HCHO into CO2 and H2O at 110 C. Finally, Mg Mn and Al hydrotalcites based compounds, activated by ultrasound, are employed as precursors to obtain high surface area mixed manganese oxide. The effect of ultrasound contribution and the elemental composition of the material (Mg / Mn) on the structural, textural, basic and catalytic properties of the resulting mixed oxides have been particularly studied.LILLE1-Bib. Electronique (590099901) / SudocSudocFranceF

Electron Paramagnetic Resonance in Combination with the Thermal Analysis, X-ray Diffraction, and Raman Spectroscopy to Follow the Structural Properties of Zr x Ce 1- x O 2 Solid Systems and Precursors

International audienc