Co<sub>2</sub>Cu<sub>1</sub>Ce<sub><i>y</i></sub>O<sub><i>x</i></sub> Mixed Metal Oxide Nanoparticles with Oxygen Vacancies as Catalysts for Toluene Oxidation
Ning Sun, Liying Wang, Yongfeng Zhang, Zhenzhu Cao, Junmin Sun
Abstract
A multimetal MOF (metal–organic framework), Ce(III)/Co 2 Cu 1 -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, Co 2 Cu 1 Ce y O x mixed metal oxides were prepared by calcination to serve as a catalyst for toluene catalytic oxidation. Co 2 Cu 1 Ce y O x had the form of nanoparticles with a uniform morphology. As a result of the experiments, the conversion percentages of the Co 2 Cu 1 Ce 0.75 O x catalyst in catalyzing the toluene oxidation reached 50% ( T 50 ) and 90% ( T 90 ) at the temperatures of 196 and 210 °C, respectively. The Co 2 Cu 1 Ce 0.75 O x 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 Co 2 Cu 1 Ce 0.75 O x 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.