Atomic Fe Embedded in Carbon Nanoshells–Graphene Nanomeshes with Enhanced Oxygen Reduction Reaction Performance

Abstract

Low-cost preparation of durable electrocatalysts is vital for energy storage and conversion. Here, we integrated two methods of synthesizing isolated iron atoms into a special carbon matrix as an advanced electrocatalyst. Atomic Fe isolation and graphene nanomeshes or curved carbon nanoshells were almost synthesized simultaneously. The hierarchical atomic Fe/carbon material with 0.53 atom % Fe exhibited superior oxygen reduction reaction (ORR) performance to Pt–C (20 wt % Pt) with 40 mV more positive onset potential, larger current density, and stronger methanol-tolerant capability. We demonstrated that the catalytic active sites were Fe isolation and coordinated with nitrogen in the porous curved carbon-graphene matrix. This strategy could be developed into a general approach to prepare atomic metal/carbon electrocatalysts.

Carbon nanotubes-based PdM bimetallic catalysts through N4-system for efficient ethanol oxidation and hydrogen evolution reaction

“…The N K -edge spectra of MnPc and PdMn-N 4 /CNTs are shown in Fig. 3b and there was no any significant change in the π* region, which indicated that no significant change in the coordination between Mn and N in both samples 45 .

Figure 3XAS spectra at Mn K -edge for PdMn/CNTs and PdMn-N 4 /CNTs ( a ) N K -edge for PdMn-N 4 /CNTs ( b ) core level of Pd 3d XPS spectra of Pd/CNTs, PdMn/CNTs and PdMn-N 4 /CNTs ( c ) Mn 2p XPS spectra of PdMn/CNTs and PdMn-N 4 /CNTs ( d ) and core level of N 1s XPS spectra of PdMn-N 4 /CNTs. ( e ) XAS and XPS data of pure (as purchased) MnPc is used for comparison.

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A flexible electromagnetic wave-electricity harvester

“…4c displayed four peaks, centering at 285.3, 288.3, 291.7, and 292.9 eV, respectively. The former two peaks corresponded to 1 s → π * and π * from non-graphitized atom, respectively, whereas the latter two peaks could be attributed to 1 s → σ * 32 . The unoccupied π * and σ* states indicated that the carbon was mainly in a sp 2 -like hexagonal structure, despite the presence of a disordered part 33 .…”

A general route via formamide condensation to prepare atomically dispersed metal–nitrogen–carbon electrocatalysts for energy technologies

“…3f. This performance is among the best for the non-pyrolysis catalyst system in alkaline media, 23,[51][52][53][54] though the performance in acid media needs further improvement. Meanwhile, the much better performance of CNT@f-FeNC170 than that of the mixture of CNT and f-FeNC also verifies the importance of the intimate affinity between f-FeNC and the support/substrate.…”