Browsing by Author "Djebarri, Baya"

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Adsorptive removal of methyl orange from aqueous solution by hydrotalcite derived catalysts
(Elsevier, 2023) Aider, Nadia; Djebarri, Baya; Touahra, Fouzia
The objective of our work is to study the adsorption of methyl orange dye over ZnAl2O4 and ZnO-ZnAl2O4 derived from hydrotalcite in order to highlight their potential as low-cost adsorbents for the treatment of water. The materials ZnAl2, Zn2Al were synthesized via co-precipitation method and were characterized using various characterization techniques, which showed that the obtained materials corresponds to the compounds of hydrotalcite. Different parameters were studied to optimize the process of methyl orange removal on samples derived from hydrotalcite, including the mass of the adsorbent, the contact time, the concentration, and pH. On the other hand, adsorption isotherms were studied using Langmuir and Freundlich models, as well as the effect of these solids on thermodynamic quantities. According to the results obtained, the ZnO-ZnAl2O4 has the greatest adsorption capacity compared to the ZnAl2O4. The interaction of these materials with the dye shows that the adsorption kinetics are fast and follows a second-order adsorption rate expression. The maximum adsorption capacity determined by the Langmuir mathematical model is about 62.85 mg/g for ZnO-ZnAl2O4 and 46.24 mg/g for ZnAl2O4 and the thermodynamic study led to the conclusion that the adsorption is endothermic and that the adsorption process is spontaneous.
Enhanced Long - term Stability and Carbon Resistance of Ni/Mn x O y - Al 2 O 3 Catalyst in Near - equilibrium CO 2 Reforming of Methane for Syngas Production
(2020) Djebarri, Baya; Touahra, Fouzia; Aider, Nadia; Bali, Bali; Sehailia, Moussa; Chebout, Redouane; Bachari, Khaldoun; Halliche, Djamila
Herein we study the catalytic activity/stability of a new generation of cheap and readily available Ni and Al-based catalysts using two Mn precursors, namely Mn(NO3)2and Mn(EDTA)2-complex in the reaction of CO2reforming of methane. In this respect, Ni/Al2O3and two types of Ni/MnxOy-Al2O3catalysts were successfully synthesized and characterized using various analytical techniques: TGA, ICP, XRD, BET, FTIR, TPR-H2, SEM-EDX, TEM, XPS, and TPO-O2. Utilization of Mn(EDTA)2-as synthetic precursor successfully furnished Ni/Al2O3-MnxOyY (Y = EDTA) catalyst which was more active during CO2reforming of methane when compared to Ni/MnxOy-Al2O3cata-lyst, synthesized using Mn(NO3)2precursor. Compared to Ni/MnxOy-Al2O3, Ni/Al2O3-MnxOyY catalyst afforded near-equilibrium conversion values at 700 °C (ca. 95% conversion for CH4and CO2, and H2/CO = 0.99 over 50 h re-action time). Also, Ni/Al2O3-MnxOyY showed more resistance to carbon formation and sintering; interestingly, after 50 h reaction time, the size of Ni0particles in Ni/MnxOy-Al2O3almost doubled while that of Ni/Al2O3-MnxOyY re-mained unchanged. The elevated conversion of CO2and CH4in conjunction with the observed low carbon deposi-tion on the surface of our best catalyst (Ni/Al2O3-MnxOyY) indicated the presence of MnxOyoxide positioning medi-ated simultaneous in-situcarbon elimination with subsequent generation of oxygen vacant sites on the surface for more CO2adsorption. Copyright © 2020 BCREC Group. All rights reserved
Méthodes séparatives en chimie organique : ce polycopié est destiné aux étudiants inscrits en première année Master
(Université M'hamed Bouguara Boumerdes : Faculté des Sciences : Département de Chimie, 2024) Djebarri, Baya
La chromatographie est une méthode physique de séparation non destructrice d’un mélange liquide ou gazeux en ses différents constituants. C’est également une méthode analytique qui a pour but d’identifier et de quantifier les composés d’un mélange homogène liquide ou gazeux. La chromatographie a une place très importante dans la pratique du laboratoire e t est utilisée couramment pour Contrôler la pureté des réactifs et des produits d'une réaction. -Suivre une réaction par analyse du milieu réactionnel. -Isoler et purifier des produits d'une réaction.
Synergistic Effect of Bimetallic Ni-Based Catalysts Derived from Hydrotalcite on Stability and Coke Resistance for Dry Reforming of Methane
(Springer Nature, 2024) Djebarri, Baya; Aider, Nadia; Touahra, Fouzia; Chebout, Redouane; Lerari, Djahida; Bachari, Khaldoun; Halliche, Djamila
Bimetallic Ni–Al and Ni–Fe nanoparticles catalysts derived from hydrotalcite were synthesized by co-precipitation method and applied in dry reforming of methane. The samples were calcined at 800 °C and the crystalline phases were assessed by X-ray diffraction coupled with Rietveld refinement. Other analyzes were carried out to study their textural and structural properties including, Thermogravimetric Analysis (TG), Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), Brunauere-Emmette-Teller (BET), Scanning Electron Microscopy and Energy Dispersive-X-ray (SEM–EDX), Temperature Programmed Reduction (TPR), Transmission Electron Microscopy (TEM) and EDS mapping. The XRD Analyses confirmed the formation of the precursor’s layered double hydroxide structure, the formation of the γ-NiFe alloy confirmed by TEM-EDS Analysis. The specific surface area of the two samples increases after calcination, attributed to the destruction of the double-layered structure at high temperature, which produced cavities or crates resulting in larger surface areas. These catalysts were evaluated in CO2 reforming of methane under continuous flow with CH4/CO2 ratio equal to 1, at atmospheric pressure and a temperature range between 400 and 700 °C. At 700 °C, the NiAlHT catalyst displayed the best CH4 conversion (87.5%) and CO2 conversion (91.4%) compared to the conversion of CH4 (79.2%) and CO2 (84.1) for NiFeHT catalyst within 10 h stability test. The iron addition to the nickel showed improved resistance to coke deposition while a slight decrease in methane conversion was observed. The possible formation of γ-NiFe alloy observed during the study of reducibility by hydrogen was invoked to account for the catalytic behavior.