Scalable synthesis of pyrazine-linked conjugated microporous polymers for high-performance proton conduction†
Abstract
The development of high-performance proton-conducting materials with outstanding chemical/physical stability is critical for the fabrication of proton-exchange membrane fuel cells (PEMFCs), and remains a significant challenge. Herein, a one-pot in situ oxidation strategy is developed to construct a pyrazine-linked conjugated microporous polymer (HD-CMP) at the gram scale from hexahydroxy triphenylene and benzenetetramine tetrahydrochloride in the presence of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in the autoclave. The obtained HD-CMP not only exhibits extended π-conjugated structures and exceptional chemical stability under harsh conditions, but also nitrogen sites on the pyrazine functional groups could serve as binding sites for anchoring H3PO4 as proton carriers. Furthermore, contact angle measurements and water adsorption isotherms indicate the high water uptake capacity and hydrophilic properties of H3PO4@HD-CMP. Attributed to these features, the resulting H3PO4@HD-CMP exhibits a high proton conductivity of 1.05 × 10−1 S cm−1 at 80 °C under 100% RH, which can be comparable to those of most materials currently reported.