Reconstructing 1D Fe Single‐atom Catalytic Structure on 2D Graphene Film for High‐Efficiency Oxygen Reduction Reaction

Abstract

The ordinary intrinsic activity and disordered distribution of metal sites in zero/one‐dimensional (0D/1D) single‐atom catalysts (SACs) lead to inferior catalytic efficiency and short‐term endurance in the oxygen reduction reaction (ORR), which restricts the large‐scale application of hydrogen−oxygen fuel cells and metal−air batteries. To improve the activity of SACs, a mild synthesis method was chosen to conjugate 1D Fe SACs with 2D graphene film (Fe SAC@G) that realized a composite structure with well‐ordered atomic‐Fe coordination configuration. The product exhibits outstanding ORR electrocatalytic efficiency and stability in 0.1 M KOH aqueous solution. DFT‐D computational results manifest the intrinsic ORR activity of Fe SAC@G originated from the newly‐formed FeN4−O−FeN4 bridge structure with moderate adsorption ability towards ORR intermediates. These findings provide new ways for designing SACs with high activity and long‐term stability.

Investigations on the ORR Catalytic Performance Attenuation of a 1D Fe Single-Atom Catalyst during the Discharge Process

“…Fe SAC@G catalysts were potentiostatically discharged at 0.88 V in 3 M KOH solutions at 25 °C for different time periods to obtain different current attenuation rates I ca and their corresponding Raman spectra are shown in Figure a. According to previous analysis, , the peaks at 236, 834, 1454, and 1527 cm –1 are assigned to the vibrations of Fe–N, C–N, C–C, and C–N–C bonds, respectively. Since the C–C bond is the strongest bond among these bonds, its peak intensity (noted as P c–c ) almost keeps unchanged for all of the catalysts with different I ca values, suggesting that the C–C bond does not substantially break during the discharge process.…”

“…SEM images of the as-prepared catalysts (a) and discharged catalysts with different current attenuation rates I ca : (b) 40% I ca ; and (c, d) 70% I ca . (e) Macrograph of (c).…”

“…Iron phthalein cyanide powders (FePc, purchased from Aladdin) were loaded in a quartz boat and put at the center of zone T1. The as-synthesized G/Cu is located at the center of zone T2 . More details are presented in the Supporting Information.…”

Recent Advances in Electrocatalysts for Alkaline Hydrogen Oxidation Reaction

“…Although various isolated atomic catalysts were used for ORR, [112,113] nitrogen reduction reaction (NRR), [114,115] and carbon dioxide reduction reaction (CRR), [116,117] the isolated atomic catalysts for HOR are few. [111] The main reason is that the research on HOR is still in its infancy, which in turn giving us more chances to design and synthesize novel isolated atomic catalysts for HOR.…”

Facile synthesis of silver nanocatalyst decorated Fe3O4@PDA core–shell nanoparticles with enhanced catalytic properties and selectivity

“…15 Therefore, avoid of aggregation and preparing Ag NPs particles with good monodispersity have become the priority tasks of preparing highly efficient and stable nanocatalysts. In the past few decades, the immobilization of nanoparticles in carriers (such as activated carbon, ZIF8, graphene, polymers) [16][17][18][19] has been used to solve the above problems.…”