Synthesis of shell/core structural nitrogen-doped carbon/silicon carbide and its electrochemical properties as a cathode catalyst for fuel cells

Porous Silicon Carbide (SiC): A Chance for Improving Catalysts or Just Another Active-Phase Carrier?

“…720,721 The as-prepared composite was evaluated as a metal-free system in the electrocatalytic cathodic ORR showing high activity, stability, and resistance to alcohol crossover phenomena, typically responsible for the poisoning of Pt-based electrocatalysts in alcohol fuel cell devices. 720 Giambastiani, Pham-Huu, and coworkers came across similar conclusions by playing with SiC networks coated with a highly N-doped mesoporous carbon network grown through a simple soaking of the non-oxide samples in an aqueous solution of food-grade components followed by controlled drying/calcination/annealing treatments. 715 The choice of these authors of a SiC core instead of a more classical C-based nanocarrier for the catalytically active N-doped carbon shell was dictated by the superior resistance to electrochemical corrosion of the sp 3 -bonded network in the former with respect to the classical sp 2 -bonded matrix in the latter.…”

“…As far as the practical application of metal-free and SiC-based electrocatalysts for the ORR is concerned, Wang and collaborators described the synthesis of a structural N-doped carbon/silicon carbide composite based on a nanoscale SiC core covered by a N-doped carbon shell. A nanoporous amorphous C layer was obtained from the acid etching of a nanocrystalline 3C-SiC powder, followed by its annealing in the presence of melanine (as C and N sources) under vacuum and high-temperature conditions. , The as-prepared composite was evaluated as a metal-free system in the electrocatalytic cathodic ORR showing high activity, stability, and resistance to alcohol crossover phenomena, typically responsible for the poisoning of Pt-based electrocatalysts in alcohol fuel cell devices . Giambastiani, Pham-Huu, and co-workers came across similar conclusions by playing with SiC networks coated with a highly N-doped mesoporous carbon network grown through a simple soaking of the non-oxide samples in an aqueous solution of food-grade components followed by controlled drying/calcination/annealing treatments .…”

A novel structural design of hybrid nanotube with CNTs and CeO2 supported Pt nanoparticles with improved performance for methanol electro-oxidation

“…Currently, the carbonsupported platinum catalyst (Pt/C) is accepted widely as anode catalyst of DMFCs. However, the issue of the insufficient durability of catalyst has become a technological bottleneck for the industrial development of DMFCs [7]. And the corrosion of carbon supports and the dissolution or sintering of platinum nanoparticles have been considered as the major contributors to the degradation of DMFCs performance [8].…”

Nitrogen and Phosphorus Dual-Doped Silicon Carbide-Derived Carbon/Carbon Nanotube Composite for the Anion-Exchange Membrane Fuel Cell Cathode

“…In terms of designing a cathode catalyst for AEMFC application, heteroatom doping as well as hierarchical porous structure (e.g., including micro/mesopores) of the nanocarbons is beneficial. It has been claimed that the hierarchical porous structure of the electrocatalyst could contribute to the improved ORR performances, in which a high level of micropores helps in creating more electrocatalytically active sites, while the mesopores benefit in facilitating the transport of O 2 . ,, From this aspect, the combination of CDC and CNT as heteroatom-doped ORR catalysts is especially attractive since a high surface area CDC could provide a high amount of ORR-active sites, ,, while CNT could not only be a platform for ORR-active sites but also helps in designing unique pore structures of the final catalyst material. ,− For example, Lilloja et al showed that a N-doped CDC/CNT composite exhibited good electrocatalytic activity toward the ORR in an alkaline medium and impressive AEMFC performance (peak power density of 310 mW cm –2 ) . However, most of the studies about heteroatom-doped nanocarbons (including composite materials) have focused on half-cell testing, e.g., by the rotating disk electrode (RDE) or rotating ring-disk electrode (RRDE) method, ,,,, but only few have comprised the real fuel cell testing. ,,, Even more, no reports on the ORR performance of dual heteroatom-doped CDC/CNT can be found.…”

“…It has been claimed that the hierarchical porous structure of the electrocatalyst could contribute to the improved ORR performances, in which a high level of micropores helps in creating more electrocatalytically active sites, while the mesopores benefit in facilitating the transport of O 2 . 4,27,28 From this aspect, the combination of CDC and CNT as heteroatom-doped ORR catalysts is especially attractive since a high surface area CDC could provide a high amount of ORR-active sites, 21,29,30 while CNT could not only be a platform for ORR-active sites but also helps in designing unique pore structures of the final catalyst material. 10,31−33 For example, Lilloja et al showed that a N-doped CDC/CNT composite exhibited good electrocatalytic activity toward the ORR in an alkaline medium and impressive AEMFC performance (peak power density of 310 mW cm −2 ).…”