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Ibtissem Lounas Hanane Zazoua Adel Saadi Zahia Mesbah Benyoucef 《Research on Chemical Intermediates》2018,44(11):6549-6567
Supported copper catalysts on low surface area silica were prepared by several methods and characterized by AAS, XRD, N2 adsorption, SEM, H2-TPR, N2O titration, TGA-DTA, UV–Vis techniques. Their hydrogenating properties were examined in the gas-phase hydrogenation of benzaldehyde. The analysis of characterization results revealed that the choice of preparation method affected the texture, composition, and structure of the calcined and reduced Cu/SiO2 catalysts. The dispersion and size distribution of copper species was present in different forms in the catalysts that exhibited low specific surface areas. In gas-phase hydrogenation of benzaldehyde to benzyl alcohol, the catalysts tested at the reaction temperatures of 160 and 200 °C were stable and conducted to a good catalytic activity and benzyl alcohol selectivity ranging between 5 and 39 µmol min?1 g?1 and 0–95%, respectively. The activity of the catalysts in gas-phase hydrogenation also depended on the particle size and the nature of copper species formed on low surface area silica. 相似文献
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Imane Boubezari Ali Zazoua Franois Bessueille Abdelhamid Errachid Nicole Jaffrezic‐Renault 《Electroanalysis》2020,32(7):1642-1650
Instant determination of glucose levels is necessary to monitor the treatment of diabetes. The next generation of electrochemical sensors aims to eliminate the use of enzymes because of their lack of stability and the complex procedure to immobilize them on the electrode. In this paper Pr1.92Ba0.08Ni0.95Zn0.05O4+δ perovskite, a A2BO4+δ type, was tested, for the first time for non enzymatic detection of glucose. It was synthesized by a sol‐gel method. The obtained crystallized powder was structurally characterized by XRD, morphologically characterized by SEM and EDX and electrochemically characterized. A monoclinic crystallographic system was formed. The presence of Pr2O3 during synthesis and calcination is in agreement with the formation of defects in the crystalline network and the disproportionation of NiIII sites into NiII and NiIV, due to the substitution of Pr by Ba. The oxido‐reduction of NiII sites is observed by cyclic voltammetry. The electrocatalytic oxidation of glucose through the electrooxidized NiII site was observed on a gold electrode, at 481 mV. The analytical performance of this glucose sensor is good in comparison to previously published ABO3 perovskite modified electrodes, in terms of dynamic range (1.5 μM–7000 μM) and detection limit (0.5 μM). Its application to human serum shows that there is no interference for glucose detection. 相似文献
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H. Zazoua A. Saadi K. Bachari D. Halliche C. Rabia 《Research on Chemical Intermediates》2014,40(3):931-946
Layered double hydroxides or hydrotalcite-like compounds with different kinds of metal ions (Mg–Al, Mg–Fe and Mg–Cr) in the brucite-like sheets were prepared by a co-precipitation method with Mg/M3+ molar ratio of ~2. The hydrotalcites were characterized by chemical analysis, X-ray diffraction, Fourier transform infrared spectroscopy, temperature programmed reduction, SEM microscopy, and specific surface area measurements. The activity is evaluated for benzaldehyde reaction. The selectivity to benzyl alcohol is always 90 % even though benzaldehyde conversion depends on the nature of the metal active phase and reaction conditions. 相似文献
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Zazoua Hanane Touahra Fouzia Sehailia Moussa Chebout Redouane Lerari Djahida Bachari Khaldoun Saadi Adel 《Research on Chemical Intermediates》2019,45(5):3273-3290
Research on Chemical Intermediates - Delafossite mixed metal oxides of the form BaCuO2 and BaCu1M1?xO2 (M?=?Ni, Fe and Co) were successfully synthesized following a sol–gel... 相似文献
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Hana Fourou Ali Zazoua Mohamed Braiek 《International journal of environmental analytical chemistry》2016,96(9):872-885
The focus of this article is the development and optimisation of a simple, sensitive, selective biosensor for the detection of heavy metals, through inhibition of β-galactosidase (β-gal) from Aspergillus oryzae after its immobilisation on an electrochemical transducer by cross-linking with glutaraldehyde. The inhibition of β-gal by Cd(II) and Cr(VI) was demonstrated by the decrease of β-gal activity monitored by the conductometric signal. Under optimal conditions, the developed voltammetric and impedimetric biosensor, based on the specific interaction of metallic ions with beta-galactosidase that increases the electron transfer of the redox probe, presented a wide range of linearity. Detection limits of 3.12 × 10–10 M (91.7 ng/L) were obtained, using both techniques, for Cr(VI). For Cd(II) detection limits were 2.85 × 10–8 M (6.95 µg/L) using EIS and 3.22 × 10–11 M (7.61 ng/L) using square wave voltammetry (SWV). 相似文献
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