We report a new hydroxyl functionalized microporous organic polymer (MOPOH) based on the polymerization of catechol with terephthalaldehyde using phenolic resin-inspired chemistry. This catechol-decorated material, with surface area of 874m2g?1and micro, mesopores, facilitates the immobilization and dispersion of Pd nanoparticles (NPs) on the polymer matrix. The surface area of the created composite (Pd@MOPOH) decreases to 419m2g?1and the pore size distribution is narrowly distributed at 1.54nm due to the filling of mesopores. The CO2capture capacities for MOPOH and Pd@MOPOH at 273K and 1bar are 13.4 and 9.2wt%, respectively. The resultant Pd NPs are crystalline and uniform with a mean diameter of 4.8nm. The well-dispersed Pd@MOPOH exhibits excellent catalytic activity toward the model reduction of 4-nitrophenol into 4-aminophenol. Significantly, nearly no Pd leaching is detected during the catalytic cycles, showing active and durable nature of the heterogeneous nanocatalyst.