Catalysts for Fuel Cells

As people turn to cleaner transportation, hydrogen fuel cell research is becoming more and more popular, especially in the field of automotive applications. Since cost is the main limiting factor of this technology, catalysts with low-cost, high-activity, and stable catalytic performance are the key to the large-scale application of fuel cells. The catalyst material reduces the activation energy of the reaction, thereby enabling the manufacture of miraculous high-efficiency fuel cells. Alfa Chemistry Catalysts provides customers with a wide range of catalysts for fuel cells.

Mechanism of Fuel Cell and Catalyst

Catalysts for Fuel Cells

• Pt and Pt-based electrocatalysts

The structure and composition of Pt and Pt-based electrocatalysts significantly affect the catalytic activity and durability of fuel cell catalysts. Electrocatalysts include platinum single metal, platinum-based alloys (including precious alloys, non-precious alloys, metal oxide alloys and non-metal alloys) and structure control alloys (nano polyhedrons, nano dendrites, and hollow and core-shell structures). Figure 1 shows the representative categories of Pt-based catalysts currently used in fuel cells.

Generally speaking, platinum nanoparticles (NPs) supported on carbon supports (Pt/C) are the most widely used as fuel cell catalysts in scientific research and business cases, mainly due to their better performance under strong acid conditions. Noble metals have higher catalytic activity and better stability.

Figure 1. Representative categories of Pt-based catalysts used in fuel cells [1]

• Non-precious metal electrocatalyst

Due to the high cost and limited operational stability of the traditionally used Pt-based cathode catalysts, the development of non-noble metal-based electrocatalysts (such as MNC, M = Co, Fe, Ni, Mn, etc.) has attracted widespread attention. Several important unsupported or carbon-supported non-noble metals are used as electrocatalysts for ORR, including non-pyrolysis and pyrolysis transition metal nitrogen-containing complexes, conductive polymer-based catalysts, transition metal chalcogenides, metal oxides/ carbide/nitride/oxynitride/carbonitride and enzyme compounds. Among them, the pyrolysis transition metal nitrogen supported on the carbon material (M–Nx/C) containing-compound is considered to be the most promising ORR catalyst.

Figure 2. Molecular structure of (a) FePc and (b, c and d) various substituted FePc molecules investigated for ORR catalytic activity and stability [2]

References

1. Xuefeng Ren. (2020). "Current progress of Pt and Pt-based electrocatalysts used for fuel cells", Sustainable Energy Fuels 4: 15-30.
2. Zhongwei Chen. (2011). "A review on non-precious metal electrocatalysts for PEMfuelcells", Energy & Environmental Science 4: 3167.