Co2Cu1CeyOx Mixed Metal Oxide Nanoparticles with Oxygen Vacancies as Catalysts for Toluene Oxidation

A multimetal MOF (metal–organic framework), Ce(III)/Co2Cu1-MOF-74, has here been synthesized in a simple and convenient manner by using the mechanical ball milling method. This method is both energy-saving and environmentally friendly. By using the obtained product compounds as a template, Co2Cu1CeyOx mixed metal oxides were prepared by calcination to serve as a catalyst for toluene catalytic oxidation. Co2Cu1CeyOx had the form of nanoparticles with a uniform morphology. As a result of the experiments, the conversion percentages of the Co2Cu1Ce0.75Ox catalyst in catalyzing the toluene oxidation reached 50% (T50) and 90% (T90) at the temperatures of 196 and 210 °C, respectively. The Co2Cu1Ce0.75Ox catalyst exhibited an abundance of multiphase interfaces and metal doping effects, which effectively induced an abundance of oxygen vacancies on the catalyst surface. Furthermore, the Co2Cu1Ce0.75Ox catalyst exhibited excellent durability within 24 h and demonstrated remarkable regenerative capabilities after steam-induced reduction by 5%. Thus, the use of MOFs as precursor compounds, which were mechanically synthesized in a green and rapid manner, helped to design high-efficiency multimetal mixed oxide nanoparticle catalysts with abundant multiphase interfaces, which could be used for toluene catalytic oxidation. This rendered possibilities for large-scale applications in related areas.