The stabilization of surfactant-assisted synthesized colloidal noble metal nanoparticles (NPs, such as Au NPs) on solids is a promising strategy for preparing supported nanocatalysts for heterogeneous catalysis because of their uniform particle sizes, controllable shapes, and tunable compositions. However, surfactant removal to obtain clean surfaces for catalysis through traditional approaches (such as solvent extraction and thermal decomposition) can easily induce the sintering of NPs, greatly hampering their use in synthesis of novel catalysts. Such unwanted surfactants have now been utilized to stabilize NPs on solids by a simple yet efficient thermal annealing strategy. After being annealed in N 2 flow, the surface-bound surfactants are carbonized in situ as sacrificial architectures that form a conformal coating on NPs and assist in creating an enhanced metal-support interaction between NPs and substrate, thus slowing down the Ostwald ripening process during post-oxidative calcination to remove surface covers.Noble metal nanoparticles (NPs) with controlled size and composition are of great interest for heterogeneous catalysis because of their unique nanostructure-dependent properties, such as high dispersion, abundant unsaturated coordination surface sites, and strong quantum confinement effects, which drastically differentiate their catalytic performance from that of bulk metals. [1, 2] As free NPs tend to aggregate and are difficult to handle in catalytic reactions, noble metal NPs are often loaded on high-surface-area solids as supported catalysts in practical applications.[3] Their catalytic performance thus not only depends on their own particle sizes and compositions but also relies heavily on the nature of the supports and the dispersion and stabilization of the NPs on the supports.[3] Therefore, the control and stabilization of ultra-fine noble metal NPs on select supports with high dispersion and adequate metal-support interaction is of great importance for heterogeneous catalysis.[1] However, owing to their low Tammann temperatures and high surface energies, nanosize noble metals (for example, Au NPs, Pt NPs, and Pd NPs) are thermodynamically unstable and tend to agglomerate/sinter on a support by either Ostwald ripening or particle coalescence.[4] This inherent problem makes the dispersion and stabilization of NPs as thermally stable heterogeneous catalysts a daunting challenge. [5] Colloidal noble metal NPs with tunable particle sizes, shapes, and compositions have been extensively used as building blocks to construct supported catalysts.[6] Generally, such NPs can be prepared with nanometer precision using surfactant-assisted approaches. [7] In Scheme 1, the resultant ultra-fine NP is surrounded by surface-bound surfactants or ligands, which enable the easy dispersion of NPs in the solvent as a stable colloidal solution. [7b] This unique colloidal stability is beneficial in catalyst loading, as it helps achieve a homogeneous dispersion of NPs on support materials.[3] However, when t...