Ceria Nanoparticles on Modified MXene for Aerobic Oxidation of 4-Methoxybenzyl Alcohol

Abstract

The development of efficient and robust metal nanoparticle catalysts for the aerobic oxidation of benzyl alcohol is crucial for advancing green chemistry. This study presents a class of ceria nanoparticle catalysts, designated as Ce-NC/CFMX-T, where “T” denotes the pyrolysis temperature. These catalysts are synthesized by pyrolyzing a mixture of Ce-MOF-801/CFMX and dicyandiamide at high temperatures, aimed at the liquid-phase aerobic oxidation of 4-methoxybenzyl alcohol to 4-methoxybenzaldehyde, using molecular oxygen as the oxidizing agent and avoiding harmful additives or bases. Among the synthesized catalysts, Ce-NC/CFMX-973 exhibited exceptional catalytic efficiency, achieving over 99.9% conversion of 4-methoxybenzyl alcohol and complete selectivity for 4-methoxybenzaldehyde. This performance was achieved under moderate conditions, using xylene as the solvent at 373 K over 8 h and an oxygen pressure of 1 atm. Kinetic analysis revealed that the activation energy for oxidizing 4-methoxybenzyl alcohol using Ce-NC/CFMX-973 was 68.5 ± 3.0 kJ/mol, which is lower than the values observed for Ce-C/CFMX-973, Ce-NC-973, and Ce-C-973. The remarkable catalytic performance of the Ce-NC/CFMX-973 catalyst is attributed to the synergistic effects between CeO₂ nanoparticles and oxygen vacancies, along with the support’s balanced acidity and basicity properties.