Heterogeneous single-metal-site catalysts (HSMSCs) have been recognized as promising materials due to the advantages of evenly distributed active metal sites, easy separation, and recyclability. Herein, we construct a single-site Ru catalyst on porous ionic polymers (Ru/PIPs-IL3) via electrostatic interactions, which is a practical and useful strategy for synthesizing HSMSCs. The strong electrostatic interactions (Δ