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Fuel cells and water electrolyzers that are cheap and efficient will form the cornerstone of a hydrogen fuel based economy, which is one of the most promising clean and sustainable alternatives to fossil fuels. These devices rely on materials called electrocatalysts to work, so the development of efficient and low-cost catalysts is essential to make hydrogen fuel a viable alternative.  Researchers at Aalto university have developed a new catalyst material to improve these technologies.

The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are the most important electrochemical reactions that limit the efficiencies of hydrogen fuel cells (for powering vehicles and power generation), water electrolyzers (for clean hydrogen production), and high-capacity metal-air batteries. Physicists and chemists at Aalto collaborating with researchers at CNRS France, and Vienna in Austria have developed a new catalyst that drive these reactions more efficiently than other bifunctional catalysts currently available. The researchers also found that the electrocatalytic activity of their new catalyst can be significantly altered depending on choice of the material on which the catalyst was deposited. 

“We want to replace traditional expesive and scarce catalysts based on precious metals like platinum and iridium with highly active and stable alternatives composed of cheap and earth-abundant elements such as transition metals, carbon and nitrogen.” says Dr Mohammad Tavakkoli, the researcher at Aalto who led the work and wrote the paper.

In collaboration with CNRS the team produced a highly porous graphene–carbon nanotube hybrid and doped it with single atoms of other elements known to make good catalysts. Graphene and carbon nanotube (CNT) are the one‐atom‐thick two- and one‐dimensional allotropes of carbon, respectively, which have attracted tremendous interest in both academia and industry due to their outstanding properties compared more traditional materials. They developed an easy and scalable method to grow these nanomaterials at the same time, combining their properties in a single product. “We are one of the leading teams in the world for the scalable synthesis of double-walled carbon nanotubes. The innovation here was to modify our fabrication process to prepare these unique samples,” said Dr Emmanuel Flahut, research director at CNRS.