Oxygen reduction reaction at MWCNT-modified nanoscale iron(ii) tetrasulfophthalocyanine: remarkable performance over platinum and tolerance toward methanol in alkaline medium

Abstract

A nanoscale iron(II) tetrasulfophthalocyanine (nanoFeTSPc) catalyst obtained by co-ordinating with hexadecyltrimethylammonium bromide and subsequently anchored onto multi-walled carbon nanotubes (MWCNTs) for oxygen reduction reaction (ORR) has been reported. Two types of MWCNTs, hydroxyl/carboxyl-functionalized (o-MWCNTs) and sulfonate-functionalized (s-MWCNTs) were used as the supporting platforms for the catalysts (nanoFeTSPc-o-MWCNT and nanoFeTSPc-s-MWCNT, only 9 wt% loading of the nanoFeTSPc). The nanoFeTSPc-o-MWCNT gave the best performance towards ORR in terms of high catalytic current density, more positive onset potential (E onset ¼ À0.02 V vs. Ag/AgCl), half-wave potential (E 1/2 ¼ À0.32 V vs. Ag/AgCl), and high catalytic rate constant (k $ 1.6 Â 10 À2 cm s

Heat treated carbon supported iron(ii)phthalocyanine oxygen reduction catalysts: elucidation of the structure–activity relationship using X-ray absorption spectroscopy

“…1,10 Iron(II)phthalocyanine (FePc) was the first such material to be examined 11,12 and has since been widely explored in catalysis and sensing including the ORR. [13][14][15][16][17] Two main synthetic routes have been developed to produce such materials. The first one is usually conducted by pyrolysis of macrocycles containing existing M-N 4 moieties.…”

Carbon-supported Co(III) dimer for oxygen reduction reaction in alkaline medium

“…Table 2 lists the ORR activity measured at 0.8 V vs. RHE of the various unpyrolyzed organometallic compounds (including metal macrocycles)-based ORR catalysts. The ORR activity of the Co(III) dimer is comparable to that of the metal organic framework of pyridine-functionalized graphene with iron porphyrin [33] and multiwalled carbon nanotube-modified nanoscale iron(II) tetrasulfophthalocyanine [39], and better than that of the iron tetrasulfophthalocyanine-coated single-walled carbon nanotubes [34] and 1-decyne-protected copper nanoparticles [36]. The mass-specific ORR activity of Co(III) dimer/C and Pt/C at 0.8 V iR-free vs. RHE (−0.067 V vs. Hg,HgO) is 0.13 A mg −1 Co and 0.3 A mg −1 Pt , respectively.…”

“…Earlier, nonmacrocycle-based chelating ligands containing organometallic compounds were explored for ORR in nonaqueous medium [30,31]. Table 2 lists the recently explored composites of organometallic complex CNMs for ORR in aqueous medium [32][33][34][35][36][37][38][39].…”

“…Catalyst loading was 140 μg cm −2 . The catalyst loadings reported in the literature vary between 80 and 400 μg cm −2 [32,33,39,43,44]. The ORR activity of the MNC catalyst was studied by linear sweep voltammetry in O 2 -saturated 0.1 N KOH solution with the electrode rotated at 1600 rpm.…”

Efforts at Enhancing Bifunctional Electrocatalysis and Related Events for Rechargeable Zinc‐Air Batteries

“…In fact, several electrocatalysts have been proven to compete favourably with PGM-based electrocatalysts for ORR. [164][165][166][167][168] The RZABs' anode and bifunctional electrocatalyst materials should be flexible and lightweight to adapt to space-saving integrations and miniaturization. [169] Rational design and modulation of the electrode materials would be a great deal to prevent agglomeration of bifunctional air electrocatalysts, poor utilization of Zn anode and electrolyte poisoning, which can eventually lead to excellent battery efficiency and stability.…”