Fe-, N-Embedded Hierarchically Porous Carbon Architectures Derived from FeTe-Trapped Zeolitic Imidazolate Frameworks as Efficient Oxygen Reduction Electrocatalysts

Abstract

During the design and construction of an efficient iron–nitrogen–carbon (Fe–N–C) electrocatalyst, it was difficult to avoid the formation of iron oxides along with the hierarchical carbon frameworks containing dispersed FeN x sites. As a result, a slow oxygen reduction reaction (ORR) occurred, making it difficult to improve the electrocatalytic property. Herein, we have successfully synthesized the Fe, N-doped hierarchically porous carbon architectures from FeTe-trapped ZIF-8 coated with polydopamine by heat treatment. During the pyrolysis process, the evaporation of tellurium could inhibit the formation of iron oxides, promote the formation of more FeN x active species, and facilitate the formation of mesoporous structure to accelerate mass transfer and increase the approachability of active species. The resulting Fe, N-doped porous carbon architectures possessed excellent ORR catalytic performance, and the half-wave potential was 10 mV more than that of the precious Pt/C catalysts. Besides, the obtained catalysts present a superb methanol tolerance and long-term durability compared to precious Pt/C catalysts in alkaline media. This work opens up new avenues for the construction of the uniformly dispersed FeN x sites catalysts for ORR.

Metalloid Te‐Doped Fe‐Based Catalysts Applied for Electrochemical Water Oxidation

“…Besides, the intrinsic semiconductor/metal characters and unique electronic structures of iron‐based catalysts endow them with excellent performance. Up to now, iron telluride (FeTe x ) is mainly applied as lithium‐ion capacitors, magnetic materials, redox reactions, and oxygen reduction electrocatalysts [24–26] . However, to the best of our knowledge, FeTe x has not yet been applied for water oxidation (Table S1).…”

“…Up to now, iron telluride (FeTe x ) is mainly applied as lithium-ion capacitors, magnetic materials, redox reactions, and oxygen reduction electrocatalysts. [24][25][26] However, to the best of our knowledge, FeTe x has not yet been applied for water oxidation (Table S1). Iron telluride is currently synthesized mainly through hydrothermal reactions, using iron salt as the iron source, sodium tellurite or tellurium powder as the tellurium source, with the participation of the strong reducing agents such as hydrazine hydrate, ethylenediamine, sodium borohydride and ethylene glycol, and relatively mild reducing agents such as glucose and ascorbic acid.…”

Uniformly bimetal-decorated holey carbon nanorods derived from metal−organic framework for efficient hydrogen evolution

“…Because of their unique structural characteristics of long-range ordered metal ions/clusters and organic linkers [22][23][24][25], MOFs can be converted to active metal species uniformly decorated in carbon materials by the pyrolysis [26][27][28]. Although a great many MOFs have been reported, MOF precursors for the use of electrocatalysts are mainly limited to a handful of MOFs, such as ZIF-8/ZIF-67 (ZIF, zeolitic imidazolate framework) [29][30][31][32][33], MOF-5 [21,34], MOF-74 [35,36], MIL-101 (MIL, Matérial Institute Lavoisier) [37,38], and HKUST-1 (HKUST, Hong Kong University of Science and Technology) [39,40], which only contain single metal species. The lack of available heterometallic MOFs for the carbonization is a current impediment to the preparation of carbon/metal nanoparticles hybridizing b-Mo 2 C with a high compositional uniformity.…”

NaCl‐Promoted Hierarchically Porous Carbon Self‐Co‐Doped with Iron and Nitrogen for Efficient Oxygen Reduction

“…[1][2][3] Regarded as the most effective ORR catalysts, platinum (Pt) and its alloys are still suffered from several critical problems, such as low abundance, high cost, low stability and methanol tolerance, which limit their wide applications. [4][5][6][7] Consequently, highly effective and durable nonprecious catalysts for ORR have been extensively studied, especially the porous carbon materials doped with heteroatoms and/or nonprecious transition metals. [3,[8][9][10][11][12][13][14] The porous carbon materials, which possess hierarchical porous structure with abundant macro-, meso-and micro-pores, and well-ordered carbon skeletons with a proper degree of graphitization and large surface area, can facilitate the mass transfer, electron conduction and exposure of numerous accessible active sites towards the reaction, thus improving the ORR performance synergistically.…”

“…Oxygen reduction reaction (ORR), the pivotal process in renewable fuel cells, generally limits the efficiency of these fuel cells due to its intrinsically sluggish kinetics [1–3] . Regarded as the most effective ORR catalysts, platinum (Pt) and its alloys are still suffered from several critical problems, such as low abundance, high cost, low stability and methanol tolerance, which limit their wide applications [4–7] . Consequently, highly effective and durable nonprecious catalysts for ORR have been extensively studied, especially the porous carbon materials doped with heteroatoms and/or nonprecious transition metals [3,8–14] …”