Cobalt–Nitrogen Co‐doped Carbon Nanotube Cathode Catalyst for Alkaline Membrane Fuel Cells

Abstract

A highly active state‐of‐the‐art catalyst was synthesized by cobalt–nitrogen co‐doping of multi‐walled carbon nanotubes (Co/N/MWCNT) as non‐precious metal catalyst using cobalt chloride and dicyandiamide by high‐temperature treatment. A range of physicochemical characterization methods were used to observe the surface structure and composition of the synthesized electrocatalyst material. The kinetics of the oxygen reduction reaction (ORR) on this catalyst material was studied in 0.1 m KOH solution by using the rotating‐disk electrode method. The Co/N/MWCNT catalyst showed excellent electrocatalytic activity for ORR in alkaline media. In addition, the performance of the catalyst in a fuel cell was evaluated by fabricating membrane electrode assemblies employing a Tokuyama® anion exchange membrane (AEM), with hydrogen and oxygen gases at various temperatures. AEM fuel cell with Co/N/MWCNT cathode catalyst exhibited a power density of 115 mW cm−2 with H2/O2 gases (100 % RH) at ambient pressure at 50 °C.

High‐performance N, P‐CNL nanocomposites as catalyst for oxygen reduction reaction in fuel cell

“…The electron transfer number of oxygen molecules has been calculated in order to study the kinetics of prepared catalysts in the oxygen reduction reaction by K‐L equation . To investigate the types of reaction pathways, all straight KL lines of N, P‐CNL‐1:1 are similar at the voltage range of 0.3‐0.8 V in Figure A indicating similar electron transfer number (n).…”

“…Transition metal/heteroatom‐doped carbon materials (MNCs) have become the most promising alternative to replace commercial platinum carbon (Pt/C) catalysts due to their low cost, wide range of raw materials, high activity, high stability, and resistance to methanol . The combination of transition metal salts and nitrogen‐doped carbon materials (such as nitrogen‐doped carbon nanotubes, nitrogen‐doped carbon nanofibers, nitrogen‐doped carbon spheres, nitrogen‐doped graphene, etc.) display superior performance according to the current research.…”

Iron and Nitrogen Co‐doped Carbide‐Derived Carbon and Carbon Nanotube Composite Catalysts for Oxygen Reduction Reaction

“…[6,7] The most active of such catalysts are typically based on carbon nanomaterials doped with nitrogen and transition metals (MÀN/C catalysts), [8][9][10][11] as they are relatively stable both chemically and mechanically, highly conductive and can be tailored to have high surface areas. [18] The third method is the direct pyrolysis of a nitrogencontaining polymer or smaller molecule in the presence of transition metals, either with or without [19] additional carbon supports such as carbon nanotubes, [20,21] carbon black, [22,23] graphene [24,25] or composites of multiple sources. This mixture is then pyrolyzed and the substrate along with inactive metal phases is removed by etching in acid mixtures, which allows for control over the porosity and structure by choosing the right substrate and reagents.…”

Graphitic Carbon‐NiCo Nanostructures as Efficient Non‐Precious‐Metal Electrocatalysts for the Oxygen Reduction Reaction

“…[3] Thus, a challenge exists to develop cost-effective and active nonprecious-metal nanostructures to replace PGM-ORR catalysts in large-scale energy technologies, particularly in fuel cells and metal-air batteries. [12][13][14][15] Nevertheless, it remains challenging to prepare composites featuring more metal active sites and thinner graphitic carbon coatings to facilitate excellent electrolyte utilization and mass transport during the ORR. [6][7][8] Recently, composites of transition metals and carbon have attracted attention because of their stable (metal) active sites and low degrees of (carbon) corrosion in harsh electrolyte environments.…”