摘要
The construction of robust coupling catalysts for accelerating electrocatalytic oxygen reduction reaction(ORR)through the modulation of the electronic structure and local atomic configuration is critical but remains challenging.Herein,we report a facile and effective isolation-polymerization-pyrolysis(IPP)strategy for high-precision synthesis of single-atomic Mn sites coupled with Fe_(3)C nanoparticles encapsulated in N-doped porous carbon matrixes(Mn SAs/Fe_(3)C NPs@NPC)catalyst derived from predesigned bimetallic Fe/Mn polyphthalocyanine(FeMn-BPPc)conjugated polymer networks by solid-phase reaction approach.Benefiting from the synergistic effects between the single-atomic Mn-N_(4)sites and Fe_(3)C NPs as well as the confinement effect of NPC,the Mn SAs/Fe_(3)C NPs@NPC catalyst exhibited excellent electrocatalytic activity and stability for ORR.The assembled Znair battery displayed larger power density of 186 mW·cm^(−2)than that of Pt/C+Ir/C-based battery.It also exhibits excellent stability without obvious voltage change after 106 cycles with 36 h.Combing in-situ Raman spectra with in-situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)characterization results indicated that the Mn-N_(4)site as an active site for the O_(2)adsorption-activation process,which effectively facilitates the generation of key*OOH intermediates and*OH desorption to promote the multielectron reaction kinetics.Theoretical calculation reveals that the excellent electrocatalytic performance originates from the charge redistribution and the d orbital shift resulting from Mn-Fe bond,which buffers the activity of ORR through the electron reservoir capable of electron donation or releasing.This work paves a novel IPP strategy for constructing high-performance coupling electrocatalyst towards the ORR for energy conversion devices.
基金
State Key Laboratory of Catalytic Materials and Reaction Engineering(RIPP,SINOPEC)
Taishan Scholars Program of Shandong Province(No.tsqn201909065)
Shandong Provincial Natural Science Foundation(Nos.ZR2021YQ15,ZR2020QB174,and ZR2019MB022)
the National Natural Science Foundation of China(Nos.22108306 and 21902182)
the Fundamental Research Funds for the Central Universities(Nos.2022YQHH01 and 22CX07009A)
the State Key Laboratory of Organic-Inorganic Composites(No.oic202101006)
Post-graduate Innovation Fund of China University of Petroleum(East China)(No.YCX2021064)
the Research Fund Program of Key Laboratory of Fuel Cell Technology of Guangdong Province,the Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education),and the Key Laboratory of Functional Inorganic Material Chemistry(Heilongjiang University),Ministry of Education.
