Recalling the driving force in Section 2.1, the island growth mode (Volmer-Weber growth) is the primary mechanism for nanoparticle formation due to more favorable enthalpic interaction within the metal itself than with the substrate. A trivial solution lies in the thermodynamic regulation of the metal-substrate interaction to prevent nanoparticle formation (i.e., stable SACs). This often leaves too few metal sites available for reactant binding and catalysis, and sintering may still occur when exposed to sufficiently harsh conditions; A non-trivial solution is to tune the supply or diffusion kinetics of free atoms via confinement or defect-engineering, which allows some degrees of freedom for dynamic response and prevents irreversible sintering into large particles. To this end, Liu et al. proposed a "nanoglue" strategy via confining atomically dispersed metal atoms on tiny oxide nanoclusters. As shown in Figures &, isolated and defective CeOx nanoglue islands with a size of less than 2 nm were grafted on high-surface-area SiO2 as the host for one Pt atom. In contrast to conventional sintering, such Pt SACs remain highly stable under oxidizing and reducing environments at high temperatures and exhibit markedly increased activity for CO oxidation in Figure . This is attributed to the mobility of the Pt atom on each CeO2 nanoglue island while preventing inter-island movement for coalescence.