Small-sized Pt-based intermetallic compounds(IMCs)with unique electronic and geometrical structures are promising candidates as next-generation oxygen-reduction reaction(ORR)catalysts in protonexchange membrane fuel c...Small-sized Pt-based intermetallic compounds(IMCs)with unique electronic and geometrical structures are promising candidates as next-generation oxygen-reduction reaction(ORR)catalysts in protonexchange membrane fuel cells(PEMFCs).However,the synthesis of IMC catalysts remains challenging owing to the trade-off relation between the alloying/ordering degree and particle aggregation/sintering under a high-temperature annealing process.Herein,we demonstrate a cuprous sulfide(Cu_(1.96)S)intermediate-assisted strategy for the scalable synthesis of PtCu_(3) intermetallic electrocatalysts on an S-doped carbon black support.We identify that the Cu_(1.96)S intermediate formed at low temperature gradually releases metallic Cu species at high temperatures to form a small-sized and uniform Pt-Cu alloy with target stoichiometry,which eventually ensures the formation of well-ordered intermetallic PtCu_(3) structures.The prepared intermetallic PtCu_(3) catalysts exhibit enhanced ORR performance with a mass activity of 3.2 A mg_(Pt)^(-1) and retain 72%of the initial activity after durability tests.展开更多
基金the National Natural Science Foundation of China(Grants 22221003 and 22071225)the Fundamental Research Funds for the Central Universities(Grant WK2060190103)+3 种基金the Joint Funds from Hefei National Synchrotron Radiation Laboratory(Grant KY2060000175)Collaborative Innovation Program of Hefei Science Center of CAS(Grant 2021HSC-CIP015)USTC Research Funds of the Double First-Class Initiative,the fellowship of China Postdoctoral Science Foundation(2022M712179)the Shenzhen Science and Technology Program(Grant JCYJ20200109110416441).
文摘Small-sized Pt-based intermetallic compounds(IMCs)with unique electronic and geometrical structures are promising candidates as next-generation oxygen-reduction reaction(ORR)catalysts in protonexchange membrane fuel cells(PEMFCs).However,the synthesis of IMC catalysts remains challenging owing to the trade-off relation between the alloying/ordering degree and particle aggregation/sintering under a high-temperature annealing process.Herein,we demonstrate a cuprous sulfide(Cu_(1.96)S)intermediate-assisted strategy for the scalable synthesis of PtCu_(3) intermetallic electrocatalysts on an S-doped carbon black support.We identify that the Cu_(1.96)S intermediate formed at low temperature gradually releases metallic Cu species at high temperatures to form a small-sized and uniform Pt-Cu alloy with target stoichiometry,which eventually ensures the formation of well-ordered intermetallic PtCu_(3) structures.The prepared intermetallic PtCu_(3) catalysts exhibit enhanced ORR performance with a mass activity of 3.2 A mg_(Pt)^(-1) and retain 72%of the initial activity after durability tests.
