Structure, synthesis, and catalytic properties of nanosize cerium-zirconium-based solid solutions in environmental catalysis

Nanosize cerium-zirconium solid solution (CZO) with a special fluorite structure has received an increasing research interest due to their remarkable advantages such as excellent oxygen storage capacity and great flexibility in their composition and structure. By partial metal (including rare earth, transition, alkaline earth or other metal) doping into CZO, the physicochemical properties of these catalytic materials can be controllable adjusted for the study of specific reactions. To date, nanosize CZO has been prepared by co-precipitation, sol-gel, surfactant-assisted approach, solution combustion, micro-emulsion, high energy mechanical milling, etc. The advent of these methodologies has prompted researchers to construct well-defined networks with customized micromorphology and functionalities. In this review, we describe not only the basic structure and synthetic strategies of CZO, but also their relevant applications in environmental catalysis, such as the purification for CO, nitrogen oxides (NOx), volatile organic compounds (VOC), soot, hydrocarbon (HC), CO2 and solid particulate matters (PM), and some reaction mechanisms are also summarized.