Electrospun Polyacrylonitrile‐Derived Co or Fe Containing Nanofibre Catalysts for Oxygen Reduction Reaction at the Alkaline Membrane Fuel Cell Cathode

Abstract

Electrospun polyacrylonitrile (PAN) based carbon nanofibres (CNF) are employed as cathode catalysts in anion-exchange membrane fuel cell (AEMFC) for the first time. The catalysts are prepared via pyrolysis of Co or Fe salt-containing PAN fibre with and without the ionic liquid (IL) additive. The catalyst material preparation is optimised by assessing the oxygen reduction reaction (ORR) activity of different transition metal and nitrogen-doped CNFs in 0.1 M KOH by rotating disc electrode method followed by testing in real AEMFC configuration. The best performance in the AEMFC is observed in case of Fe and IL containing PAN fibre that was pyrolysed at 1000°C and additionally treated in an acid solution (Fe/IL-PAN-A1000). In the AEMFC, the Fe/IL-PAN-A1000 catalyst showed the maximum power density (P max) of 289 mW cm À 2 , which is 82 % of the P max obtained with commercial Pt/C cathode catalyst (352 mW cm À 2).

Study on the Simple Surface Treatments of N, P Dual‐doped Carbon as Metal‐free Catalyst for Metal‐air Batteries

“…Therefore, after NaBH 4 treatment, the spectra centers of the obtained PNC−B and PNC−B/E are obviously shifted to lower binding energy for decreasing ∼0.4 eV compared to PNC and PNC−E (seen the inset of Figure 3a). Commonly, the binding energy of P−C, P−N and P−O bonds are at 132.7 eV, 133.4 eV and 135.2 eV, respectively [15,26,40–42] . Accordingly, the P 2p spectra of PNC and PNC−E were fitted, as shown in Figure 3a.…”

“…Commonly, the binding energy of PÀ C, PÀ N and PÀ O bonds are at 132.7 eV, 133.4 eV and 135.2 eV, respectively. [15,26,[40][41][42] Accordingly, the P 2p spectra of PNC and PNCÀ E were fitted, as shown in Figure 3a. For PNC, the P element mainly exists in the form of PÀ N bonds.…”

“…Dual‐doping of heteroatoms was demonstrated to be more effective to achieve high ORR activity compared to the nitrogen doping [19–24] . Recently, in order to pursue much better ORR performance, a number of transition metal elements were introduced again into heteroatom‐doped carbon matrix, in which the presence of metal‐heteroatom‐carbon bonds can further prompt the ORR catalytic activities [25–27] . However, the introduction of transition metal elements weakens the ultimate cost advantage over metal‐free carbon‐based catalysts [28–31] .…”

“…[19][20][21][22][23][24] Recently, in order to pursue much better ORR performance, a number of transition metal elements were introduced again into heteroatom-doped carbon matrix, in which the presence of metal-heteroatom-carbon bonds can further prompt the ORR catalytic activities. [25][26][27] However, the introduction of transition metal elements weakens the ultimate cost advantage over metal-free carbon-based catalysts. [28][29][30][31] After all transition metals are also important resources, especially with the increasing depletion.…”

A Highly Efficient Fe−N−C Electrocatalyst with Atomically Dispersed FeN4 Sites for the Oxygen Reduction Reaction

“…Furthermore, the diffusion‐limiting current density (J L ) of FeSA/HNPC (5.60 mA cm −2 ) is larger than Pt/C (5.36 mA cm −2 ). Such a larger J L might be attributed to the contribution of the additional mass‐transfer and O 2 ‐diffusion caused by the disk location of RDE or the partly non‐laminar electrolyte flows caused by a rough electrode surface [49,50] . It is worth mentioning that FeSA/HNPC at a low electrocatalyst loading (0.2 mg cm −2 ) on the working electrode demonstrates a competitive ORR performance in terms of E onset and E 1/2 relative to representatively reported NNMEs (0.1 to 2 mg cm −2 ) in 0.1 M KOH solution (Table S6).…”