Ordered mesoporous porphyrinic carbons with very high electrocatalytic activity for the oxygen reduction reaction

Abstract

The high cost of the platinum-based cathode catalysts for the oxygen reduction reaction (ORR) has impeded the widespread application of polymer electrolyte fuel cells. We report on a new family of non-precious metal catalysts based on ordered mesoporous porphyrinic carbons (M-OMPC; M = Fe, Co, or FeCo) with high surface areas and tunable pore structures, which were prepared by nanocasting mesoporous silica templates with metalloporphyrin precursors. The FeCo-OMPC catalyst exhibited an excellent ORR activity in an acidic medium, higher than other non-precious metal catalysts. It showed higher kinetic current at 0.9 V than Pt/C catalysts, as well as superior long-term durability and MeOH-tolerance. Density functional theory calculations in combination with extended X-ray absorption fine structure analysis revealed a weakening of the interaction between oxygen atom and FeCo-OMPC compared to Pt/C. This effect and high surface area of FeCo-OMPC appear responsible for its significantly high ORR activity.

Highly active electrocatalyst for oxygen reduction reaction from pyrolyzing carbon-supported iron tetraethylenepentamine complex

“…In order to accelerate the future development of the FeTEPA/C catalyst, it is essential to well understand and elucidate its active sites. As for the active site in the FeTEPA/C catalyst studied in the present work, we believe that the transition metal Fe is just served as a catalyst to prompt the incorporation of electron-accepting nitrogen atoms in the conjugated carbon plane and the significantly high ORR activity comes from the net positive charge on carbon atoms created by the nitrogen dopants of a higher electronegativity than that of carbon [13,[29][30][31][32][33]. Many other researchers also get similar conclusion.…”

One-step synthesis of dual-transition metal substitution on ionic liquid based N-doped mesoporous carbon for oxygen reduction reaction

“…The transition metal does not participate itself in the ORR. It serves to catalyze the formation of nitrogen doping structures in the carbon framework that are active toward the ORR by increasing the surface concentration of nitrogen groups and active sites [12,[18][19][20][21][22][23]. Furthermore, the presence of transition metals can enhance the electron donor property of the carbon matrix by catalyzing nitrogen doped graphitic carbon structure during the pyrolysis step [19].…”

Rational Design and Synthesis of Low-Temperature Fuel Cell Electrocatalysts

“…16c produced a measured area current activity of 9.9 mA cm −2 at 0.9 V iR-free and a peak power density of 0.9 W cm −2 . Other framework substrate methods, such as a combination of various carbon materials [164][165][166] and synthesis with silica template [131,167,168] or NaCl template [169], were also found to create abundant channels/pores to facilitate mass transportation.…”