Noble-Metal-Free Iron Nitride/Nitrogen-Doped Graphene Composite for the Oxygen Reduction Reaction
| Autor: | Zoltán Kónya, Gergő Ballai, Lívia Vásárhelyi, Tamás Varga, Ákos Kukovecz, Albert Oszkó, Henrik Haspel |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Graphene General Chemical Engineering Oxide chemistry.chemical_element General Chemistry engineering.material Article law.invention Catalysis lcsh:Chemistry Iron nitride chemistry.chemical_compound lcsh:QD1-999 chemistry Chemical engineering law engineering Noble metal Particle size Rotating disk electrode Platinum |
| Zdroj: | ACS Omega ACS Omega, Vol 4, Iss 1, Pp 130-139 (2019) |
| ISSN: | 2470-1343 |
| Popis: | Considerable effort has been devoted recently to replace platinum-based catalysts with their non-noble-metal counterparts in the oxygen reduction reaction (ORR) in fuel cells. Nitrogen-doped carbon structures emerged as possible candidates for this role, and their earth-abundant metal-decorated composites showed great promise. Here, we report on the simultaneous formation of nitrogen-doped graphene and iron nitride from the lyophilized mixture of graphene oxide and iron salt by high-temperature annealing in ammonia atmosphere. A mixture of FeN and Fe2N particles was formed with average particle size increasing from 23.4 to 127.0 nm and iron content ranging from 5 to 50 wt %. The electrocatalytic oxygen reduction activity was investigated via the rotating disk electrode method in alkaline media. The highest current density of 3.65 mA cm–2 at 1500 rpm rotation rate was achieved in the 20 wt % catalyst via the four-electrode reduction pathway, exceeding the activity of both the pristine iron nitride and the undecorated nitrogen-doped graphene. Since our catalysts showed improved methanol tolerance compared to the platinum-based ones, the formed non-noble-metal system offers a viable alternative to the platinum-decorated carbon black (Pt/CB) ORR catalysts in direct methanol fuel cells. |
| Databáze: | OpenAIRE |
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