Spatially Confined Construction of Ultrasmall Pd Clusters Within Nitro‐Bonded Covalent Organic Frameworks for Efficient Alkyne Semihydrogenation

Confinement of metal species in porous supports is an effective strategy to optimize hydrogenation performance ascribing to tunable nanopore environments. However, only focusing on the electronic structure modulation for metal species has limited the design of improved catalysts. Herein, spatial confinement strategy is reported for constructing ultrasmall metal clusters in nitro-bonded COF (M@TpPa-NO