TY - JOUR
T1 - Noble-Metal-Free Iron Nitride/Nitrogen-Doped Graphene Composite for the Oxygen Reduction Reaction
AU - Varga, Tamás
AU - Vásárhelyi, Lívia
AU - Ballai, Gergő
AU - Haspel, Henrik
AU - Oszkó, Albert
AU - Kukovecz, Ákos
AU - Kónya, Zoltán
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: Financial support from the Hungarian National Research Development and Innovation Office through grants GINOP- 2.3.2-15-2016-00013, NKFIH OTKA K120115 (Z.K.), and K126065 (A.K.) is gratefully acknowledged.
PY - 2019/1/3
Y1 - 2019/1/3
N2 - 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 FeN 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 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.
AB - 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 FeN 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 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.
UR - http://hdl.handle.net/10754/631143
UR - https://pubs.acs.org/doi/10.1021/acsomega.8b02646
UR - http://www.scopus.com/inward/record.url?scp=85059586983&partnerID=8YFLogxK
U2 - 10.1021/acsomega.8b02646
DO - 10.1021/acsomega.8b02646
M3 - Article
C2 - 31459319
SN - 2470-1343
VL - 4
SP - 130
EP - 139
JO - ACS Omega
JF - ACS Omega
IS - 1
ER -