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.
A fuel cell is an electrochemical cell that converts the chemical energy of fuel (usually hydrogen) and oxidant (usually oxygen) into electrical energy through redox reactions.
Electrochemical devices must use catalyst materials to function and provide high performance. In fuel cells, oxidation reactions need to be combined with reduction reactions, which includes hydrogen oxidation reaction (HOR), hydrogen evolution reaction (HER), oxygen reduction reaction (ORR), water oxidation (also known as water electrolysis), and so on. At the anode, the catalyst causes the fuel to undergo an oxidation reaction, producing ions (usually positively charged hydrogen ions) and electrons. At the cathode, the catalyst reacts ions, electrons, and oxygen to form water and possibly other products.
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 
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