Fe–N–C exhibits excellent electrocatalytic oxygen reduction reaction (ORR) activity, but the synergistic effect between metallic and isolated iron species remains unclear. Herein, N-doped carbon nanostructure encapsulated Fe3C nanoparticles coupled with atomically dispersed Fe–N4 (Fe3C–FeN/NC) were synthesized by a general pyrolytic strategy. The introduction of Zn species promoted the formation of Fe–N4 during pyrolysis. Theoretical calculations indicated that the oxygen adsorption capacity of Fe3C was further enhanced by Fe–N4, which facilitated the breakage of O–O bonds. As a result, its onset potential of 0.95 V surpassed that of Fe3C/NC (0.89 V) and NC (0.85 V) in 0.1 M KOH electrolyte. Only a 7 mV negative shift was obtained after 5000 cycles, which outperformed Pt/C catalysts. The assembled primary Zn–air battery (ZAB) displayed a high open-circuit potential of 1.41 V and a maximum power density of 166 mW cm−2 with an excellent specific capacity of 745 mA h g−1, outperforming the battery assembled with a commercial Pt/C catalyst.
#1Shichao Ding(WSU: Washington State University)H-Index: 12
#2Zhaoyuan Lyu(WSU: Washington State University)H-Index: 7
Last. Yuehe Lin(WSU: Washington State University)H-Index: 129
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Carbon-based single-atom catalysts (CSACs) have recently received extensive attention in catalysis research. However, the preparation process of CSACs involves a high-temperature treatment, during which metal atoms are mobile and aggregated into nanoparticles, detrimental to the catalytic performance. Herein, an ion-imprinting derived strategy is proposed to synthesize CSACs, in which isolated metal-nitrogen-carbon (Me-N4 -Cx ) moiety covalently binds oxygen atoms in Si-based molecular sieve fra...
Last. Iryna V. Zenyuk(UCI: University of California, Irvine)H-Index: 24
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While Fe-N-C materials are a promising alternative to platinum for catalyzing oxygen reduction in acidic polymer fuel cells, limited understanding of their operando degradation restricts rational approaches towards improved durability. Here we show that Fe-N-C catalysts initially comprising two distinct FeNx sites (S1 and S2) degrade via the transformation of S1 into iron oxides while the structure and number of S2 were unmodified. Structure-activity correlations drawn from end-of-test 57Fe Moss...
#1Xiaohong Xie(PNNL: Pacific Northwest National Laboratory)H-Index: 7
#2Cheng He(WashU: Washington University in St. Louis)H-Index: 7
Last. Mark H. Engelhard(Environmental Molecular Sciences Laboratory)H-Index: 107
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The development of catalysts free of platinum-group metals and with both a high activity and durability for the oxygen reduction reaction in proton exchange membrane fuel cells is a grand challenge. Here we report an atomically dispersed Co and N co-doped carbon (Co–N–C) catalyst with a high catalytic oxygen reduction reaction activity comparable to that of a similarly synthesized Fe–N–C catalyst but with a four-time enhanced durability. The Co–N–C catalyst achieved a current density of 0.022 A ...
Single-atom catalysts have been considered as representative non-noble metal catalysts for replacing the platinum catalyst. Fundamentally, the dispersion of metal atoms on a carbon support with limited surface area results in extremely low loading of the active metal, leading to a thick electrode and low volumetric energy density. In this study, we present a facile strategy for increasing the active metal densities on the M–N–C catalyst through the use of dual active sites such as Fe–Nx and nano...
#1Qi Liu(MOE: Chinese Ministry of Education)H-Index: 91
#2Xu Liu(MOE: Chinese Ministry of Education)H-Index: 10
Last. Honggang Fu(MOE: Chinese Ministry of Education)H-Index: 86
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The construction of a high performance and stable non-precious metal–air-cathode is of great significance for a Zn–air battery (ZAB). Herein, 3D nanosheets consisting of N-doped carbon conglutinated CoFe alloy nanoparticles grown on carbon cloth (CoFe@NC/CC) have been prepared through simple electrodeposition and subsequent thermal decomposition. The cathode showed excellent activity and stability for the bifunctional oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER), due t...
Developing efficient, inexpensive, and durable electrocatalysts for the oxygen reduction reaction (ORR) is important for the large-scale commercialization of fuel cells and metal-air batteries. Herein, a hierarchically porous bimetallic Fe/Co single-atom-coordinated N-doped carbon (Fe/Co-Nx -C) electrocatalyst for ORR is synthesized from Fe/Co-coordinated polyporphyrin using silica template-assisted and silica-protection synthetic strategies. In the synthesis, first silica nanoparticles-embedded...
: The applications of the most promising Fe-N-C catalysts are prohibited by their limited intrinsic activity. Manipulating the Fe energy level through anchoring electron withdrawing ligands is found effective in boosting the catalytic performance. However, such regulation remains elusive as the ligands are only uncontrollably introduced owning to their energetically instable nature. Here we report a rational manipulation strategy for introducing axial bonded O to the Fe sites, attained through h...
Abstract null null The search for ultrafast and simple methods to fabricate non-noble metal catalysts to boost electrocatalytic oxygen reduction reaction (ORR) is still ongoing. Herein, we demonstrate a one-step microwave-assisted heating method to prepare copper nitride/iron/iron carbide nanoparticle hybrids (CuNC/Fe/Fe3C/CNT). This ultrafast heating method induces plentiful carbon-wrapped metal and Fe3C nanoparticles that are attached to the surface of CNT and scattered nanosheets. The CuNC/Fe...
#2Zihan Meng(WUT: Wuhan University of Technology)H-Index: 3
Last. Haolin Tang(WUT: Wuhan University of Technology)H-Index: 51
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Abstract null null Development of noble metal-free catalysts with great electrocatalytic performance and stability is of importance for electrochemical energy conversion and storage devices. Herein, we reported the synthesis of trifunctional catalysts with three-dimension (3D) hierarchically porous nitrogen-doped carbon framework with Ni-Co dual metal-involving and carbon nanotubes growth derived from nickel metal-organic framework. The as-synthesized catalyst exhibited better oxygen reduction r...
#2Shichun Mu(WUT: Wuhan University of Technology)H-Index: 72
Owing to the advantage of atomic utilization, the single-atom catalyst has attracted much attention and been employed in multifarious catalytic reactions. Its definite site configuration is favorable for exploring the actual active centers and corresponding reaction mechanism. At the atomic scale, the tunable site configuration, from central metal atoms, coordinated heteroatoms, peripheral dopants, and feasible polymetallic centers to the synergetic intrinsic carbon defects, can effectively augm...
#1Saijun Wang(ZJNU: Zhejiang Normal University)H-Index: 2
#2Haiyan Wang(ZJNU: Zhejiang Normal University)H-Index: 5
Last. Yong Hu(ZJNU: Zhejiang Normal University)H-Index: 45
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Abstract null null A robust trifunctional electrocatalyst based on N-doped graphitic carbon nanosheets encapsulated with CoFe alloy nanocrystals (CoFe@NC/NCHNSs) is synthesized, which exhibits a positive half-wave potential (E1/2) of 0.92 V for oxygen reduction reaction (ORR), and low overpotentials of 285 mV and 120 mV at 10 mA cm−2 for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. The superior trifunctional electrocatalytic performance can be accredited t...
