Simultaneously Engineering the Coordination Environment and Pore Architecture of Metal–Organic Framework‐Derived Single‐Atomic Iron Catalysts for Ultraefficient Oxygen Reduction

Abstract

Designing highly efficient and durable electrocatalysts that accelerate sluggish oxygen reduction reaction kinetics for fuel cells and metal–air batteries are highly desirable but challenging. Herein, a facile yet robust strategy is reported to rationally design single iron active centers synergized with local S atoms in metal–organic frameworks derived from hierarchically porous carbon nanorods (Fe/N,S‐HC). The cooperative trithiocyanuric acid‐based coating not only introduces S atoms that regulate the coordination environment of the active centers, but also facilitates the formation of a hierarchically porous structure. Benefiting from electronic modulation and architectural functionality, Fe/N,S‐HC catalyst shows markedly enhanced ORR performance with a half‐wave potential (E1/2) of 0.912 V and satisfactory long‐term durability in alkaline medium, outperforming those of commercial Pt/C. Impressively, Fe/N,S‐HC‐based Zn–air battery also presents outstanding battery performance and long‐term stability. Both electrochemical experimental and density functional theoretical (DFT) calculated results suggest that the FeN4 sites tailored with local S atoms are favorable for the adsorption/desorption of oxygen intermediate, resulting in lower activation energy barrier and ultraefficient oxygen reduction catalytic activity. This work provides an atomic‐level combined with porous morphological‐level insights into oxygen reduction catalytic property, promoting rational design and development of novel highly efficient single‐atom catalysts for the renewable energy applications.

Tuning d‐Band Center of Pt by PtCo‐PtSn Heterostructure for Enhanced Oxygen Reduction Reaction Performance

“…Pt-based catalysts are considered to be the most effective catalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). [1][2][3][4] However, the sluggish oxygen reduction kinetics and poor durability of Pt-based materials limit their widespread application. [5][6][7][8][9][10] Based on the Sabatier principle for designing catalysts rationally, the catalysts bind O ad should be at an optimal value.…”

In Situ S-Doping Strategy of Promoting Iron Coordinated by Nitrogen-Doped Carbon Nanosheets for Efficient Oxygen Reduction Reaction

“…Their Fourier transform (FT) k3-weighted extended X-ray absorption fine structure (EXAFS) curves of DAP 1 -TIT 0.4 -DTB 0.6 and references in Figure d show that there only exists a main peak in FT-EXAFS of DAP 1 -TIT 0.4 -DTB 0.6 at about 1.5 Å, which is attributed to the scattering of Fe-N. Moreover, there is Fe-Fe contribution at about 2.2 Å and no Fe-S contribution at about 1.8 Å in DAP 1 -TIT 0.4 -DTB 0.6 , , confirming that the Fe atoms in DAP 1 -TIT 0.4 -DTB 0.6 are stabilized by N and atomically dispersed on the supports.…”

“…As shown in Figure 1h,i, the signal peak of Fe and N has a high degree of overlap, indicating that there would be N x coordination around the Fe atom, while it is noted that there is a small amount of S (the S content is less, and the detected signal peak is relatively weak) and one of the S signal peaks is highly coincident with N and Fe and another peak of S is close to N, indicating that there may be two chemical bonds of Fe-N-S and N-S in the sample. 41 Furthermore, from the individual Fe element distribution map, it can be inferred that the distance between Fe atoms is between 0.25 and 0.5 nm. As shown in Figure 1, the successful synthesis of S-doped Fe-N-C nanosheets via this in situ doping strategy is clearly confirmed.…”

Heteroatom doped M–N–C single-atom catalysts for high-efficiency oxygen reduction reaction: regulation of coordination configurations

“…50 Meanwhile, owing to the novel active structure, these catalysts also show excellent catalytic activity. Liu et al 51 prepared an atomically dispersed Fe/N, S-HC catalyst by calcination of trithiocyanuric acid (TCA)-assisted MOFs. The catalyst exhibited excellent electrocatalytic activity for the ORR with an onset potential ( E onset ) of 0.99 V and an E 1/2 of 0.912 V ( vs. RHE) as well as a J K of 32.64 mA cm −2 at 0.85 V in O 2 -saturated 0.1 M KOH solution, which were comparable to those of the commercial Pt/C catalyst.…”