Abstract The selectivity and over-oxidation obtained in the oxidation of m -xylene to isophthalic acid by V 2 O 5 nanoparticles encapsulated in TiO 2 matrix are controlled by the size of the V 2 O 5 nanoparticles. In this reaction when the size of V 2 O 5 nanoparticles was less than 45 nm at least 16–30% of the m -xylene was lost as carbon oxides. In this work, V 2 O 5 @TiO 2 catalysts, with V 2 O 5 loadings from 10 to 20 wt% were prepared by trapping V 2 O 5 nanoparticles in a matrix of mesoporous TiO 2 . We demonstrate herein results of m -xylene oxidation in a fixed-bed reactor (i.d. = 10 mm) for production of isophthalic acid. The air-calcined samples of the catalysts were characterized by different techniques such as FT-IR, XRD, Diffuse-reflectance UV–Vis, FE-SEM, EDX, BET, XPS, and TEM. This novel configuration of V 2 O 5 particles in the TiO 2 matrix not only prevents leaching of the catalyst but also improves the catalyst reusability. The optimal amount of V 2 O 5 trapped in the TiO 2 matrix was 15 wt%. The best V 2 O 5 @TiO 2 catalyst activation temperature was 350 °C.

中文翻译：

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V 2 O 5 粒径对间二甲苯氧化的影响：使用封装在 TiO 2 晶格中的 V 2 O 5 作为一种高效且可重复使用的催化剂对间二甲苯进行气相氧化

摘要 V 2 O 5 纳米颗粒包裹在TiO 2 基体中，将间二甲苯氧化成间苯二甲酸的选择性和过氧化反应受V 2 O 5 纳米颗粒的尺寸控制。在该反应中，当 V 2 O 5 纳米颗粒的尺寸小于 45 nm 时，至少 16-30% 的间二甲苯以碳氧化物的形式损失。在这项工作中，通过将 V 2 O 5 纳米颗粒捕获在介孔 TiO 2 基质中，制备了 V 2 O 5 @TiO 2 催化剂，其 V 2 O 5 负载量为 10 至 20 wt%。我们在此展示了在固定床反应器 (id = 10 mm) 中氧化间二甲苯以生产间苯二甲酸的结果。催化剂的空气煅烧样品通过不同的技术进行表征，如 FT-IR、XRD、漫反射 UV-Vis、FE-SEM、EDX、BET、XPS 和 TEM。TiO 2 基体中V 2 O 5 颗粒的这种新颖配置不仅防止了催化剂的浸出，而且提高了催化剂的可重复使用性。捕获在TiO 2 基体中的V 2 O 5 的最佳量为15wt%。最佳V 2 O 5 @TiO 2 催化剂活化温度为350℃。