Novel molybdenum-cerium based heterogeneous catalysts for efficient oxidative coupling of benzylamines under eco-friendly conditions

This work demonstrates that MoOx/CeO2ZrO2 solid acid acts as a promising catalyst in the solvent-free oxidative-coupling of benzylamine into diben-zylimine with O-2 as the oxidant. The benzylamine conversions were found to be 27, 51, 74, and 99 % for CeO2, CeO2-ZrO2, MoOx/CeO2, and MoOx/CeO2-ZrO2 catalysts, respectively. The MoOx/CeO2-ZrO2 catalyst also efficiently converts various substituted- and secondary-benzylamines under solvent-free conditions with 02 resulting in moderate to excellent yields. Remarkably, a high selectivity of similar to 99.6-99.9 % towards the dibenzylimine product was found for all reaction conditions. The outstanding performance of MoOx/CeO2-ZrO2 catalyst was attributed to high specific surface area, improved structural defects, and superior acid properties. [GRAPHICS] The MoOx/CeO2-ZrO2 catalyst show an outstanding performance in the oxidation of benzylamine and its derivatives, which is attributed to abundant acidic sites, large number of oxygen vacancies, and superior BET surface area.