CeO₂-Based Frustrated Lewis Pairs via Defective Engineering: Formation Theory, Site Characterization, and Small Molecule Activation

Activation of small molecules is considered to be a central concern in the theoretical investigation of environment- and energy-related catalytic conversions. Sub-nanostructured frustrated Lewis pairs (FLPs) have been an emerging research hotspot in recent years due to their advantages in small molecule activation. Although the progress of catalytic applications of FLPs is increasingly reported, the fundamental theories related to the structural formation, site regulation, and catalytic mechanism of FLPs have not yet been fully developed. Given this, it is attempted to demonstrate the underlying theory of FLPs formation, corresponding regulation methods, and its activation mechanism on small molecules using CeO₂ as the representative metal oxide. Specifically, this paper presents three fundamental principles for constructing FLPs on CeO₂ surfaces, and feasible engineering methods for the regulation of FLPs sites are presented. Furthermore, cases where typical small molecules (e.g., hydrogen, carbon dioxide, methane oxygen, etc.) are activated over FLPs are analyzed. Meanwhile, corresponding future challenges for the development of FLPs-centered theory are presented. The insights presented in this paper may contribute to the theories of FLPs, which can potentially provide inspiration for the development of broader environment- and energy-related catalysis involving small molecule activation.