Recent advances on the construction of encapsulated catalyst for catalytic applications

In heterogeneous catalytic reactions, supported metal catalysts have attracted increasing attention for the environmental remediation and industrial manufacture due to their inherent catalytic capacity. However, leaching, agglomeration, and poisoning of active metal particles lead to catalyst deactivation, thereby limiting their applications. To avoid this, strategies to protect the active metals from such inactivating processes are major areas of research. Emerging encapsulation strategies, in which active species are coated by protective shells, have proven to be a powerful technology to enhance catalytic performance by creating a well-developed structure about the active catalytic sites. This review highlights the recent advances on preparation method and application of encapsulated catalysts since 2016. Building upon the traditional confinement effect, new categories and extended concepts of encapsulation are introduced. In parallel, effects of encapsulation structure on performance and key factors controlling the structure of encapsulated catalyst are discussed definitely in this review. Finally, future perspectives on opportunities and challenges for further research in the field are given at the end of this paper.