Construction of mesoporous ceria-supported gold catalysts with rich oxygen vacancies for efficient CO oxidation

Abstract

Bearing unique redox nature and high oxygen storage capacity, ceria (CeO2) has always been a promising CO oxidation catalyst support for gold (Au) catalysts and the like. Herein, a series of Au–CeO2–P (P stands for pH value) samples was prepared by a co-precipitation method with the assistance of an alkaline environment and amino groups functionalized ordered mesoporous polymer (OMP-NH2). Afterward, all samples described above were characterized that the Au–CeO2–P catalysts are made of Au–Ce–O solid solution and Au nanoparticles (NPs) supported on CeO2. It turns out that OMP-NH2 is not just a simple sacrificial template for mesoporous structure, but also plays an important role as an amino source, explaining the presence of rich oxygen vacancies. Due to the concentration of oxygen vacancies in Au–Ce–O solid solution is the key factor for the oxygen mobility of CO oxidation, the catalytic results also demonstrate that the catalytic activity of Au–CeO2–P catalysts is related to the concentration of their oxygen vacancies. Moreover, Au–CeO2-9.6 with a highest concentration of oxygen vacancies (as high as 13.98%) in Au–CeO2–P catalysts exhibits the best catalytic activity (complete conversion at 10 °C).