Nickel oxide powder was prepared by simple calcination of nickel nitrate hexahydrate at 500 °C for 5 h and used as a catalyst for the oxidation of cyclohexane to produce the cyclohexanone and cyclohexanol—KA oil. Molecular oxygen (O₂), hydrogen peroxide (H₂O₂), t-butyl hydrogen peroxide (TBHP) and meta-chloroperoxybenzoic acid (m-CPBA) were evaluated as oxidizing agents under different conditions. m-CPBA exhibited higher catalytic activity compared to other oxidants. Using 1.5 equivalent of m-CPBA as an oxygen donor agent for 24 h at 70 °C, in acetonitrile as a solvent, NiO powder showed exceptional catalytic activity for the oxidation of cyclohexane to produce KA oil. Compared to different catalytic systems reported in the literature, for the first time, about 85% of cyclohexane was converted to products, with 99% KA oil selectivity, including around 87% and 13% selectivity toward cyclohexanone and cyclohexanol, respectively. The reusability of NiO catalyst was also investigated. During four successive cycles, the conversion of cyclohexane and the selectivity toward cyclohexanone were decreased progressively to 63% and 60%, respectively, while the selectivity toward cyclohexanol was increased gradually to 40%.

中文翻译：

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温和条件下环己烷在散装氧化镍上的高效氧化

将六水合硝酸镍在 500 ℃下简单煅烧 5 h 制备氧化镍粉末，并作为催化剂用于环己烷氧化制取环己酮和环己醇—KA 油。分子氧(O ₂ )、过氧化氢(H ₂ O ₂ )、叔丁基过氧化氢(TBHP)和间氯过氧苯甲酸( m -CPBA)在不同条件下作为氧化剂进行了评价。与其他氧化剂相比，m -CPBA 表现出更高的催化活性。使用 1.5 当量的m-CPBA作为供氧剂在70 ℃下24 h，在乙腈作为溶剂中，NiO粉末对环己烷氧化制KA油表现出优异的催化活性。与文献报道的不同催化体系相比，首次将约 85% 的环己烷转化为产物，KA 油选择性为 99%，其中环己酮和环己醇的选择性分别约为 87% 和 13%。还研究了 NiO 催化剂的可重复使用性。在连续四个循环中，环己烷的转化率和对环己酮的选择性分别逐渐降低至 63% 和 60%，而对环己醇的选择性逐渐增加到 40%。