Synergize Strong and Reactive Metal‐Support Interactions to Construct Sub‐2 nm Metal Phosphide Cluster for Enhanced Selective Hydrogenation Activities

Strong metal-support interactions (SMSI) are crucial for stabilizing sub-2 nm metal sites, e.g. single atom (M₁) or cluster (M_n). However, further optimizing sub-2 nm sites to break the activity-stability trade-off due to excessive interactions remains significant challenges. Accordingly, for the first time, we propose synergizing SMSI with reactive metal-support interactions (RMSI). Comprehensive characterization confirms that the SMSI stabilizes the metal and regulates the aggregation of Ni₁ into Ni_n site within sub-2 nm. Meanwhile, RMSI modulates Ni_n through sufficiently activating P in the support and eventually generates sub-2 nm metal phosphide Ni₂P cluster (Ni₂P_n). The synergetic metal-support interactions triggered the adaptive coordination and electronic structure optimization of Ni₂P_n, leading to the desired substrate adsorption-desorption kinetics. Consequently, the activity of Ni₂P_n site greatly enhanced towards the selective hydrogenations of p-chloronitrobenzene and alkynyl alcohol. The formation rates of target products are up to 20.2 and 3.0 times greater than that of Ni₁ and Ni_n site, respectively. This work may open a new direction for metal-support interactions and promote innovation and application of active sites below 2 nm.