In situ confined pyrolysis preparation of graphene-wrapped FePt nanoparticles anchored on N-doped hierarchically porous graphitic carbon nanoflakes for boosting oxygen reduction reaction

Wang, Yu; Chen, Min‐Te; Ye, Xin; Wang, Ai‐Jun; Tu, Gaomei; Zhang, Lu; Feng, Jiu‐Ju

doi:10.1016/j.apsusc.2022.154475

Cited by 9 publications

(3 citation statements)

References 62 publications

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“…The N 1s core-level spectrum for Co@N–C/N–KB showed four major peaks, which could readily be assigned to pyridinic-N (398.8 eV), pyrrolic-N (399.8 eV), graphitic-N (401.1 eV), and N–O (404.8 eV) . As described above, the presence of pyridinic-N and graphitic-N species in the carbon support is expected to be highly beneficial for ORR electrocatalysis, lowering the onset potential and increasing the limiting diffusion current density. , Figure e compares the surface N speciation for Co@N–C/N–KB, Co@N–C/N–KB(NL), and Co/N–KB. The relative N speciation in the three catalysts is presented graphically in Figure f.…”

Section: Resultsmentioning

confidence: 90%

“…31 As described above, the presence of pyridinic-N and graphitic-N species in the carbon support is expected to be highly beneficial for ORR electrocatalysis, lowering the onset potential and increasing the limiting diffusion current density. 20,33 Figure 2e compares the surface N speciation for Co@N−C/N−KB, Co@N−C/ N−KB(NL), and Co/N−KB. The relative N speciation in the three catalysts is presented graphically in Figure 2f.…”

Section: Resultsmentioning

confidence: 99%

“…Wang et al demonstrated that Co nanoparticles protected by pyridinic-N-doped carbon offered a low ORR overpotential . Alternatively, graphitic-N species can also affect ORR by optimizing the electronic configuration of C atoms to facilitate O 2 adsorption and promote the four-electron ORR, thereby increasing the limiting current density for catalyzing ORR. , Very recently, Wei et al established that an abundance of graphitic-N was beneficial for boosting the performance of Co nanoparticle-based electrocatalysts towards ORR . Therefore, Co-based N–C catalysts with carbon supports rich in pyridinic-N and graphitic-N species are highly desirable for efficient four-electron ORR electrocatalysis.…”

Section: Introductionmentioning

confidence: 99%

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l-Alanine-Assisted Synthesis of a Hierarchically Porous Co@N–C/N-Ketjenblack Carbon Catalyst for Oxygen Reduction in Zn–Air Batteries

Zhang

et al. 2023

Ind. Eng. Chem. Res.

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The commercialization of zinc–air batteries (ZABs) and many types of fuel cells hinges on the discovery of non-precious metal catalysts with high activity and durability for the oxygen reduction reaction (ORR). Herein, we describe a simple and scalable l-alanine-assisted thermal pyrolysis strategy [utilizing l-alanine, urea, Ketjenblack carbon (KB), and CoCl2 as precursors] that yielded a Co@N–C/N–KB catalyst with outstanding ORR performance in alkaline media. The addition of l-alanine in the pyrolysis-step increased the proportion of pyridinic-N + graphitic-N in the Co@N–C/N–KB catalyst, with highly conductive KB-promoting electron transfer kinetics during ORR. These attributes, together with the hierarchical porosity of the catalyst [presence of micropores, mesopores (dominant), and macropores], gave Co@N–C/N–KB an onset potential of 0.91 V vs RHE, a half-wave potential of 0.84 V vs RHE, a limiting current density of −5.86 mA cm–2, a Tafel slope of 63.7 mV dec–1, and an excellent durability and methanol tolerance (superior to a commercial 20 wt % Pt/C catalyst in almost all these aspects). A ZAB constructed with Co@N–C/N–KB as the cathode catalyst delivered an impressive open-circuit voltage of 1.519 V, a high power density of 204.5 mW cm–2, an energy density up to 790 mA h gZn –1, and very stable operation with charge–discharge cycling, thus offering great promise for practical devices.

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Section: Resultsmentioning

confidence: 90%