A hierarchically porous polymer (HPP) consisting of micropores (∼1 nm) within a 3D continuous mesoporous wall (∼15 nm) was used to support well-defined Pt nanoparticles (2 nm in diameter) as a heterogeneous catalyst for the Suzuki–Miyaura cross-coupling reaction in the liquid phase. The ligand-capped nanoparticles were loaded into the polymer and treated with plasma to expose the active surface. The dual porosity was essential: the block polymer-templated mesopores provided the reactants facile access to the nanoparticle center, which was firmly immobilized by the microporous surface. Compared to inorganic mesoporous silica supports, which are intrinsically susceptible to basic hydrolysis, the Pt-HPP featured higher activity for all halide leaving groups, even in green solvents, as well as excellent recyclability. Only 5% decrease in activity was observed after 10 cycles. Pt-HPP was one of the most active heterogeneous catalysts for aryl chloride substrates compared to literature Pt or Pd examples.

Metal catalysts are generally supported on hard inorganic materials because of their high thermochemical stabilities. Here, we support Pd catalysts on a thermochemically stable but “soft” engineering plastic, polyphenylene sulfide (PPS), for acetylene partial hydrogenation. Near the glass transition temperature (~353 K), the mobile PPS chains cover the entire surface of Pd particles via strong metal-polymer interactions. The Pd-PPS interface enables H2 activation only in the presence of acetylene that has a strong binding affinity to Pd and thus can disturb the Pd-PPS interface. Once acetylene is hydrogenated to weakly binding ethylene, re-adsorption of PPS on the Pd surface repels ethylene before it is further hydrogenated to ethane. The Pd-PPS interaction enables selective partial hydrogenation of acetylene to ethylene even in an ethylene-rich stream and suppresses catalyst deactivation due to coke formation. The results manifest the unique possibility of harnessing dynamic metal-polymer interaction for designing chemoselective and long-lived catalysts.