Effective Oxygen Reduction Reaction Performance of FeCo Alloys In Situ Anchored on Nitrogen-Doped Carbon by the Microwave-Assistant Carbon Bath Method and Subsequent Plasma Etching

Abstract

Electrocatalysts with strong stability and high electrocatalytic activity have received increasing interest for oxygen reduction reactions (ORRs) in the cathodes of energy storage and conversion devices, such as fuel cells and metal-air batteries. However, there are still several bottleneck problems concerning stability, efficiency, and cost, which prevent the development of ORR catalysts. Herein, we prepared bimetal FeCo alloy nanoparticles wrapped in Nitrogen (N)-doped graphitic carbon, using Co-Fe Prussian blue analogs (Co3[Fe(CN)6]2, Co-Fe PBA) by the microwave-assisted carbon bath method (MW-CBM) as a precursor, followed by dielectric barrier discharge (DBD) plasma treatment. This novel preparation strategy not only possessed a fast synthesis rate by MW-CBM, but also caused an increase in defect sites by DBD plasma treatment. It is believed that the co-existence of Fe/Co-N sites, rich active sites, core-shell structure, and FeCo alloys could jointly enhance the catalytic activity of ORRs. The obtained catalyst exhibited a positive half-wave potential of 0.88 V vs. reversible hydrogen electrode (RHE) and an onset potential of 0.95 V vs. RHE for ORRs. The catalyst showed a higher selectivity and long-term stability than Pt/C towards ORR in alkaline media.

Core‐shell FeCo N‐doped biocarbons as stable electrocatalysts for oxygen reduction reaction in fuel cells

“…25,27 Recently, FeCo alloy@N-doped graphite carbon was synthesized by using a combination of microwave-assisted carbon bath and dielectric barrier discharge plasma treatment. 28 The results indicated that the co-existence of Fe/Co N sites and core-shell structure could significantly promote the ORR. Nevertheless, the aforementioned catalysts were typically synthesized by using complicated heat treatment of transition metals with macrocyclic nitrogen complexes, [29][30][31][32] Prussian blue analogs 33,34 and ionic liquids [35][36][37] which could be too expensive to be practically utilized.…”

“…Moreover, the N‐coordinated FeCo alloys electrocatalysts could further enhance the ORR activity and long‐term durability in both acid and alkaline solution 25,27 . Recently, FeCo alloy@N‐doped graphite carbon was synthesized by using a combination of microwave‐assisted carbon bath and dielectric barrier discharge plasma treatment 28 . The results indicated that the co‐existence of Fe/CoN sites and core‐shell structure could significantly promote the ORR.…”

A Review on the Promising Plasma-Assisted Preparation of Electrocatalysts

“…Carbon-based materials have more advantages than traditional materials, such as low costs, various structures, and good electrical and thermal conductivity. The excellent catalytic performance can be obtained by tailoring carbon-based materials with specific sizes, doping types, contents, morphologies and structures, promoting active site exposure, increasing the transport of reaction-related substances, and enhancing the transfer of electrons throughout the electrode [120,121]. At the same time, more defects become the active sites of the electrocatalyst after heteroatom doping.…”

Metal Organic Framework Derived MnO2-Carbon Nanotubes for Efficient Oxygen Reduction Reaction and Arsenic Removal from Contaminated Water

“…These efforts resulted in promising ORR catalysts which can be broadly classified into three categories: non-PGM metal catalysts [2], metal-free catalysts especially hetero-atom doped carbons [3] and hybrids of non-PGM catalysts with carbon nano-structures [4]. Amongst these three, the third type of carbon-metal hybrids which consists of nano sized non-PGM metal compounds of iron [5], cobalt [6], manganese [7] etc. embedded/dispersed/anchored on nano scaled carbons such as graphene [8], carbon nanotubes [9] and carbon nanofibers [10] have rapidly evolved as attractive alternatives to PGM based ORR electro-catalysts.…”