Metal organic frameworks derived M-N-C catalysts have been discovered as promising alternatives to Pt-based catalysts in oxygen reduction reaction(ORR).However,the dominated micropores in their porous structures stron...Metal organic frameworks derived M-N-C catalysts have been discovered as promising alternatives to Pt-based catalysts in oxygen reduction reaction(ORR).However,the dominated micropores in their porous structures strongly restrain the mass transfer and lead to insufficient utilization of active sites.Here,we proposed a dualtemplate strategy to improve the catalytic performance of ZIF-8 derived M-N-C catalysts.Both the silica and sodium chloride templates created mesopores,which may intensified the mass transfer.Moreover,the molten sodium chloride connected the individual ZIF-8 crystals form highly graphitized carbon structure which had better stability and conductivity.The as-synthesized(FeCo)HPNC@NaCl catalyst exhibited similar ORR activity to commercial Pt/C under acidic conditions with half-wave potential of 0.808 V.The catalyst expressed high stability with 12 mV decrease of half-wave potential after 5000 cycles and 80%remained activity after 100000 s operation.Moreover,we tested the catalyst in fuel cell for practical application,achieving a high peak power density of 427 mW cm^(-2).展开更多
基金supported by the National Key Research and Development Program of China(2019YFA0210300)the National Natural Science Foundation of China(21922802)+3 种基金the Beijing Natural Science Foundation(JQ19007)Talent cultivation of State Key Laboratory of Organic-Inorganic Composites“Double-First-Class”construction projects(XK180301,XK1804-02)Distinguished Scientist Program at BUCT(buctylkxj02).
文摘Metal organic frameworks derived M-N-C catalysts have been discovered as promising alternatives to Pt-based catalysts in oxygen reduction reaction(ORR).However,the dominated micropores in their porous structures strongly restrain the mass transfer and lead to insufficient utilization of active sites.Here,we proposed a dualtemplate strategy to improve the catalytic performance of ZIF-8 derived M-N-C catalysts.Both the silica and sodium chloride templates created mesopores,which may intensified the mass transfer.Moreover,the molten sodium chloride connected the individual ZIF-8 crystals form highly graphitized carbon structure which had better stability and conductivity.The as-synthesized(FeCo)HPNC@NaCl catalyst exhibited similar ORR activity to commercial Pt/C under acidic conditions with half-wave potential of 0.808 V.The catalyst expressed high stability with 12 mV decrease of half-wave potential after 5000 cycles and 80%remained activity after 100000 s operation.Moreover,we tested the catalyst in fuel cell for practical application,achieving a high peak power density of 427 mW cm^(-2).
