CLIMATE CHANGE AND HUMAN ACTIVITIES IMPACT ON THE GROUNDWATER OF THE EASTERN MOROCCO: CASE OF TRIFFA PLAIN AND SHALLOW COASTAL MEDITERRANEAN AQUIFER AT SAÏDIA

Located at the North-eastern part of Morocco the plain of Triffa and the area of Saïdia are under a semiarid climate (Fig1). The water resources in this zone are rather fragile and influenced by a highly irregular rainfall distribution, both in time (annual and inter-annual distribution) and in space with a yearly average which does not exceed 240 mm

Nanoparticulate TiO2-promoted PtRu/C catalyst for methanol oxidation: TiO2 nanoparticles promoted PtRu/C catalyst for MOR

To improve the electrocatalytic properties of PtRu/C in methanol electrooxidation, nanoparticulate TiO2-promoted PtRu/C catalysts were prepared by directly mixing TiO2 nanoparticles with PtRu/C. Using cyclic voltammetry, it was found that the addition of 10 wt% TiO2 nanoparticles can effectively improve the electrocatalytic activity and stability of the catalyst during methanol electro-oxidation. The value of the apparent activation energy (Ea) for TiO2-PtRu/C was lower than that for pure PtRu/C at a potential range from 0.45 to 0.60 V. A synergistic effect between PtRu and TiO2 nanoparticles is likely to facilitate the removal of CO-like intermediates from the surface of PtRu catalyst and reduce the poisoning of the PtRu catalysts during methanol electrooxidation. Therefore, we conclude that the direct introduction of TiO2 nanoparticles into PtRu/ C catalysts offers an improved facile method to enhance the electrocatalytic performance of PtRu/C catalyst in methanol electrooxidation.Web of Scienc

Particle-size effect for oxygen reduction and methanol oxidation on Pt/C inside a proton-exchange membrane

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X-ray-absorption near-edge structure study of the electrooxidation reaction of CO on Pt50Ru50 nanoparticles

International audienceX-ray absorption near edge structure (XANES) spectra at the Ru K absorption edge were recorded on Pt50Ru50 nanoparticles during the electro-oxidation of CO. They are compared with the spectra obtained at the same electrochemical potential under inert gas. In the latter case, the XANES spectra change drastically in shape whereas in the former case they do not. The change in shape is related to a change in oxidation state of ruthenium atoms. This result clearly shows that the rate-determining step rds for CO oxidation is the oxidation of ruthenium atoms on nanometric Pt50Ru50 particles