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Résumé :
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Mesoporous zirconia was prepared by the surfactant-assisted route, using cetyltrimethylammonium bromide as cationic surfactant. The synthesized zirconia was employed as support for copper and nickel bimetallic catalysts in the hydrodehalogenation reaction of chlorobenzenes and substituted chlorobenzenes at room temperature. The catalysts were characterized by nitrogen adsorption-desorption, X-ray powder diffraction, Fourier-transfer infrared spectroscopy (FTIR), transmittance electron micrograph (TEM), UV-vis diffuse reflectance spectroscopy (UV—vis DRS), temperature programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS). The nitrogen adsorption—desorption studies revealed that the modified samples retain the mesoporosity. TEM studies showed uniform distribution of metals having 5-10 nm particles size on the support surface. The bimetallic catalyst exhibited a higher H2 chemisorption capacity relative to monometallic catalysts. For catalytic hydrodehalogenation of chlorobenzene, bimetallic catalyst showed 95% conversion with 100% selectivity for benzene as compared to monometallic catalysts, indicative of the synergy effect of copper, nickel supported on zirconia.
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