Postsynthetic Modification of a Network Polymer of Intrinsic Microporosity and Its Hydrogen Adsorption Properties

An intrinsically microporous high surface area (772 m2 g–1) hexaazatrinaphthylene-based network polymer has been synthesized. Additionally, the material was postmodified via the introduction of palladium ions to determine the effect of metalation on the properties of the assembly. Both the unmodified as-synthesized and metal-modified polymers were characterized using elemental analysis, Fourier transform infrared spectroscopy, solid-state 13C cross-polarization-magic-angle spinning NMR spectroscopy, Brunauer–Emmett–Teller surface area analysis, X-ray photoelectron spectroscopy, X-ray diffraction analysis (XRD), small-angle X-ray scattering, and thermogravimetric analysis techniques. The hydrogen uptake capacities of these materials were determined for a wide range of pressures up to 2000 bar. The palladium functionalization changed the intermolecular chain distances in the polymer, enhanced the microporosity, and increased the hydrogen uptake at ambient temperature.