Electron-Rich Acetylenic Nanostructures with In Situ Chelated Ultrafine Palladium Nanoclusters for Efficient...

The development of uniformly distributed ultrafine metallic nanoclusters for advanced catalysts has attracted significant interest. However, synthesizing supports with specific electronic environments and well-defined pores to prevent aggregation remains challenging. Here, we report a facile palladium/copper cocatalyzed polycondensation to synthesize carbon-rich acetylenic nanostructures, poly(1,3,5-triethynylbenzene) (PTEB), for the in situ chelation of ultrafine Pd nanoclusters (∼0.4 nm). The extensive π-conjugated configuration of PTEB provides an electron-rich environment that enhances Pd coordination through charge transfer, while its intrinsic pore structures ensure exceptional Pd dispersibility and effective spatial confinement. This synergistic electronic and spatial design in Pd/PTEB catalysts exhibits impressive catalytic activities in liquid-phase reactions, achieving a remarkable turnover frequency of 15 039 molC=C molPd-1 h-1 in the semihydrogenation of 1-octyne and a rate constant of 2.26 × 107 min-1 gPd-1 for 4-nitrophenol reduction. These performances represent a significant improvement over commercial and previously reported Pd catalysts, demonstrating promising advances for stable and active heterogeneous catalysts.