Yolk@Shell Nanoreactors Carrying a Cluster of Metal Nanocrystals Stabilized Inside the Hollow Carbon Shell

Synthesis and stabilization of ultrasmall metal nanocrystals at high temperature have always been challenging due to their self‐aggregating behavior. Here, we introduce a strategy to synthesize a cluster of tiny metal nanocrystals (~3 nm) inside a hollow carbon shell as yolk@shell‐type architecture following a metal‐coordination‐based nanocrystal stabilization at high temperature (500  ° C). The successful catalytic reduction of 2‐amino‐4‐nitrophenol demonstrates the efficiency of such nanoreactor in chemical transformation. Further adaptation of this strategy helps in synthesizing bimetallic (Au/Pt, Au/Pd, and Au/Ru) nanocrystals, which unfolds the possibilities to design advanced new‐generation catalysts.