This research describes the preparation of cobalt-based catalysts supported on Nb₂O₅ substrates of various forms: rods (Nb₂O₅-R), grids (Nb₂O₅-G), and spherical structures (Nb₂O₅-S). These catalysts demonstrated diverse reactivity in toluene oxidation, which correlated with their individual physical and chemical traits and the interfacial interaction between cobalt oxide and the Nb₂O₅ support. Notably, the catalyst with a spherical Nb₂O₅ support (CoO_x/Nb₂O₅-S) outperformed the catalysts with other supports and showed the best activity in oxidizing toluene. The investigation underscored the role of the unique features of the Nb₂O₅ substrate in augmenting the catalyst's efficacy in toluene adsorption and activation. Density functional theory (DFT) revealed more facile toluene adsorption on CoO_x/Nb₂O₅-S (−0.65 eV) and reduced energy requirements for oxygen vacancy creation and adsorption. This suggested that the CoO_x/Nb₂O₅-S catalyst enhanced surface oxygen mobility and boosted catalytic efficiency.

中文翻译：

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Nb2O5 负载氧化钴催化甲苯氧化的形貌依赖性


本研究描述了负载在各种形式的 Nb ₂ O ₅基底上的钴基催化剂的制备：棒状 (Nb ₂ O ₅ -R)、网格 (Nb ₂ O ₅ -G) 和球形结构 (Nb ₂ O ₅ - S）。这些催化剂在甲苯氧化中表现出不同的反应活性，这与其各自的物理和化学特性以及氧化钴和Nb ₂ O ₅载体之间的界面相互作用相关。值得注意的是，具有球形Nb ₂ O ₅载体的催化剂(CoO _x /Nb ₂ O ₅ -S)的性能优于具有其他载体的催化剂，并且在氧化甲苯方面表现出最好的活性。该研究强调了 Nb ₂ O ₅基质的独特特性在增强催化剂吸附和活化甲苯功效方面的作用。密度泛函理论 (DFT) 揭示了 CoO _x /Nb ₂ O ₅ -S (-0.65 eV) 上更容易吸附甲苯，并降低了氧空位产生和吸附的能量需求。 这表明CoO _x /Nb ₂ O ₅ -S催化剂增强了表面氧迁移率并提高了催化效率。