Iron-Based Electrocatalysts for Energy Conversion: Effect of Ball Milling on Oxygen Reduction Activity

Abstract

In this work, we synthesized new materials based on Fe(II) phthalocyanine (FePc), urea and carbon black pearls (BP), called Fe-N-C, as electrocatalysts for the oxygen reduction reaction (ORR) in neutral solution. The electrocatalysts were prepared by combining ball-milling and pyrolysis treatments, which affected the electrochemical surface area (ECSA) and electrocatalytic activity toward ORR, and stability was evaluated by cyclic voltammetry and chronoamperometry. Ball-milling allowed us to increase the ECSA, and the ORR activity as compared to the Fe-N-C sample obtained without any ball-milling. The effect of a subsequent pyrolysis treatment after ball-milling further improved the electrocatalytic stability of the materials. The set of results indicated that combining ball-milling time and pyrolysis treatments allowed us to obtain Fe-N-C catalysts with high catalytic activity toward ORR and stability which makes them suitable for microbial fuel cell applications.

One-Step Synthesis of Mn4 Molecular Electrocatalysts Assembled on Different Nanocarbon Architectures for Efficient Oxygen Reduction

“…1). On the contrary, this increase in oxygen content is not observed for Vulcan derived sample in agreement with the structure of pristine Vulcan nanoparticles and the minor structural changes after milling in presence of MPc [54].…”

“…Nonetheless, most of reported works combined ball-milling with other procedures; in particular, Wang et al [48] obtained Co-containing composites by ball-milling and subsequent heat-annealing as promising electrocatalysts towards the ORR in alkaline medium. Moreover, Costa de Oliveira et al [54] combined dry impregnation, ball-milling process and pyrolysis treatments in the presence of iron phthalocyanines (FePc), urea and carbon black to obtain Fe-N-C catalysts with enhanced ORR activity and stability in neutral medium. Wang et al [55] also reported a combined preparation method of ball-milling with an additional pyrolysis treatment, leading to Co nanoparticles on C-N nanosheets with good catalytic performance in a wide pH range.…”

“…Other works have also focused on the preparation of Co-N-C catalysts by following similar strategies [56]. Interestingly, ball-milling has been reported to promote stronger intermolecular π-π interactions and good MPc distribution in metal phthalocyanines on carbon materials [52,54]. In addition, low temperatures prevent the structural damage of MN 4 complexes.…”

Hydrogels containing water soluble conjugates of silver(i) ions with amino acids, metabolites or natural products for non infectious contact lenses

“…The ATR-FT-IR spectrum of AGU shows vibration bands at 1674 and 3354 cm -1 , which are attributed to the ν(C=O) and ν(N-H), respectively (Figure S3). The corresponding vibration bands in the IR spectrum of urea, are observed at 1690 and 3355 cm -1 (Figure S4) [25][26]. The ν(C-N) vibration band is observed at 1465 cm −1 in the spectrum of AGU [25].…”

Precise and scalable fabrication of metal pair-site catalysts enabled by intramolecular integrated donor atoms

“…46 These results indicate that the milling balls with high kinetic energy decomposed MPc and simultaneously triggered chemical reactions between the metal species and NSC. 47,48 (Cu,Mn)/NSC produced from the pyrolysis of BM-(NSC + MPc) retained the characteristic XPS peaks of BM-(NSC + MPc), along with markedly enhanced graphitic N and reduced S (C]S-C and C-S-C) peaks. This means that the pyrolysis further induced chemical-bond reconstruction, which increased the graphitization and electron-donating ability of the carbon support.…”