Preparation Of 1,3,5-Trichlorobenzene-Based Polyphenylene Networks And Their Hydrogen-Storage Performance

Microporous materials,especially microporous materials with wealthy ultramicropores?pore diameter smaller than 1 nm?,have great potential in hydrogen storage.In this thesis,polymers constituted by cyclohexa-m-phenylene?CHP?and by crosslinking phenyl with ethanediamine have been synthesized through intermolecular condensation,using 1,3,5-trihalophenylene as the main raw material.The formation mechanisms of the two-dimensional?2D?polyphenylene networks?PPNs?were demonstrated through molecular dynamics simulations.Further,the H₂-uptake capacity was investigated for the resulting PPNs.The results show:?1?2D PPNs with wealthy micropores can be obtained by a benzene thermal-based Wurtz reaction,using 1,3,5-trihalophenylene and metal Na as the raw materials.?2?Molecular dynamics simulation results show that PPNs with 2D layered structure can be formed through???interactions.?3?The micropores of 2D PPNs derived from the Wurtz reaction can be finely tuned through simple aneal treatment,and the sample obtained after anneal treatment at 520°C possesses a high content?80.7%?of micropores.?4?The H₂-uptake capacity of PPNs has no direct relationship with individual textual parameters such as SBET,Smicropore,Vtotal pore,Vmicropore,and Vmesopore,but has close relationship with ultromicropore distribution at 0.5?0.8 m,.Further,the H₂-uptake capacity of PPNs increases as the Vultramicropore 0.5?0.8nm increases.?5?PPNs featured with moderate S_BET(459.3?564.9 m² g^?1),high V_{ultramicropore 0.5-0.8nm},and micropores concentrated at 0.69?0.71 nm can be obtained with anneal treatment at 500?520?.The as-obtained samples exhibit superior H₂-uptake capacity(4.28?5.39mmol g^?1)when measured at 77 K and 1 atm.?6?The H₂ adsorption on PPNs at temperatures over 273 K is dominated by chemisorption rather than physisorption.?7?PPNs constituted by crosslinking phenyl with ethanediamine were prepared through a solvothermal method,using 1,3,5-trihalophenylene and ethanediamine as the raw materials.However,the samples obtained by annealing the PPNs at 500?550°C exhibit inferior H₂-uptake capacities,due to their relatively low S_BET.