Catalytic Oxidation of Aniline to Azoxybenzene Over CuCr₂O₄ Spinel Nanoparticle Catalyst

Abstract

Cationic surfactant cetyltrimethylammonium chloride-mediated hydrothermal preparation of CuCr 2 O 4 spinel nanoparticles has been reported. This CuCr 2 O 4 spinel nanoparticle catalyst has been characterized by XRD, XPS, SEM, TEM, TGA, and ICP-AES. Characterization results showed the formation of CuCr 2 O 4 spinel nanoparticles with sizes between 25 and 50 nm. It was found that the catalyst can selectively convert aniline to azoxybenzene with H 2 O 2 as oxidant. The effect of different reaction parameters like reaction temperature, H 2 O 2 to aniline molar ratio, reaction time, and so forth have been studied in detail. An aniline conversion of 78% with azoxybenzene selectivity of 92% can be achieved over this catalyst at 70 °C. The catalyst did not show any leaching up to five reuses, showing the true heterogeneity of the catalyst. However, significant H 2 O 2 decomposition occurs on the catalyst necessitating its usage in five-fold excess.

Fabrication of CuCr2O4 spinel nanoparticles: A potential catalyst for the selective oxidation of cycloalkanes via activation of Csp3–H bond

“…The CuCr 2 O 4 spinel nanoparticles were prepared hydrothermally by modifying our own preparation method taking nitrate precursors of copper and chromium [13]. All chemicals were used without further purification.…”

Preparation and Characterization of Copper Chromium Oxide Nanoparticles Using Modified Sol‐Gel Route and Evaluation of Their Microwave Absorption Properties

“…Copper chromite composite oxide is a versatile catalyst and has been employed as a catalyst for chemical reactions such as hydrogenation, dehydrogenation, oxidation, alkylation, etc. Accordingly, it finds a wide range of commercial applications . Recently, we have reported the photocatalytic property of CuCr 2 O 4 nanoparticles .…”

Facile Synthesis of Titanium-Loaded MCM-48 as an Efficient Heterogeneous Catalyst for Selective Oxidation of Aniline to Azoxybenzene

“…Bal et al . reported silver supported tungsten oxide nanostructured catalyst as efficient candidate for oxidation of aniline to azoxybenzene using H 2 O 2 at room temperature whereas using CuCr 2 O 4 spinel nano catalyst the same group reported 78% aniline conversion with 92% selectivity to azoxybenzene at 70 °C ,. Reddy et al .…”