The selectivity and over-oxidation obtained in the oxidation of m-xylene to isophthalic acid by V2O5 nanoparticles encapsulated in TiO2 matrix are controlled by the size of the V2O5 nanoparticles. In this reaction when the size of V2O5 nanoparticles was less than 45 nm at least 16-30% of the m-xylene was lost as carbon oxides. In this work, V2O5@TiO2 catalysts, with V2O5 loadings from 10 to 20 wt% were prepared by trapping V2O5 nanoparticles in a matrix of mesoporous TiO2. We demonstrate herein results of m-xylene oxidation in a fixed-bed reactor (i.d. = 10 mm) for production of isophthalic acid. The aircalcined 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 V2O5 particles in the TiO2 matrix not only prevents leaching of the catalyst but also improves the catalyst reusability. The optimal amount of V2O5 trapped in the TiO2 matrix was 15 wt%. The best V2O5@TiO2 catalyst activation temperature was 350 degrees C. (C) 2018 Elsevier Ltd. All rights reserved.