Isolated Single Iron Atoms Anchored on N‐Doped Porous Carbon as an Efficient Electrocatalyst for the Oxygen Reduction Reaction

Abstract

The development of low-cost, efficient, and stable electrocatalysts for the oxygen reduction reaction (ORR) is desirable but remains ag reat challenge.H erein, we made ah ighly reactive and stable isolated single-atom Fe/N-doped porous carbon (ISA Fe/CN) catalyst with Fe loading up to 2.16 wt %. The catalyst showed excellent ORR performance with ah alf-wave potential (E 1/2 )o f0 .900 V, whicho utperformed commercial Pt/C and most non-precious-metal catalysts reported to date.B esides exceptionally high kinetic current density (J k )o f3 7.83 mV cm À2 at 0.85 V, it also had ag ood methanol tolerance and outstanding stability.E xperiments demonstrated that maintaining the Fe as isolated atoms and incorporating nitrogen was essential to deliver the high performance.First principle calculations further attributed the high reactivity to the high efficiency of the single Fe atoms in transporting electrons to the adsorbed OH species.

Turning main-group element magnesium into a highly active electrocatalyst for oxygen reduction reaction

“…1) which is denoted as M (C or A) N x C according to N coordination numbers. Alkaline electrolyte, commonly used in a typical ORR experiment for N-coordinated metal moieties, is chosen to evaluate the ORR performance 10,30 . The free energy diagram for ideal ORR catalyst model is illustrated in Supplementary Fig.…”

“…The X-ray photoelectron spectroscopy (XPS) spectrum of N 1s in Fig. 3g can be deconvoluted into four peaks corresponding to pyridinic-N, pyrrolic-N, Mg-Nx (corresponding to N a 38 of MgPc which bonds with Mg) and graphitic-N, respectively 30,39 . The Mg 1s and 2p spectrum in Supplementary Fig.…”

Fabrication of Single‐Atom Catalysts with Precise Structure and High Metal Loading

“…The CoN 2 moieties outperform most previously reported nonprecious metal catalysts due to the strong interaction with peroxide . In a later study, FeN 4 moieties showed exceptional ORR performance ( E 1/2 = 0.900 V) in 0.1 m KOH solution . We employed our Fe–Co dual atoms catalyst in a fuel cell test, and the result revealed that it outperformed most reported Pt‐free catalysts in both H 2 /O 2 and H 2 /air conditions .…”

“…With these fascinating characteristics, SACs now rival nanoscale counterparts and continues to grow at an astonishing rate . Recently, we demonstrated the application of the SACs in heterogeneous catalysis ( Figure ), including oxygen reduction reaction (ORR), fuel cells, carbon dioxide (CO 2 ) reduction, selective hydrogenation and oxidation, and ammonia (NH 3 ) decomposition . For ORR, the CoN 2 moieties ( E 1/2 = 0.881 V) displayed improved ORR performance over commercial Pt/C (0.811 V) in 0.1 m KOH solution.…”

Efficient Solar‐Assisted O2 Reduction Using a Cofacial Iron Porphyrin Dimer Catalyst Integrated into a p‐CuBi2O4 Photocathode

“…Indeedc atalyzed ORR is achieved with high efficiencya nd selectivity both in nature by cytochromecoxidases [1] and relatedo xidases [2] and in many fuel cells by preciousP t-based catalysts. [3] Recently,s ubstantial progress has been achievedi nt he electrochemical ORR with variousn on-precious Fe, [4,5] Co, [6,7] Mn, [8] Cu, [9][10][11] and Ni [11] catalysts.…”