Researchers have developed a new catalyst made from biomass that offers a promising alternative to the scarce and expensive platinum currently used in fuel cells and metal-air batteries. The breakthrough, published in the scientific journal Biochar, shows how renewable raw materials can be converted into high-quality materials for clean energy technologies.
From wood biomass to advanced catalyst
The new catalyst is based on biochar, also known as biocarbon, which is derived from wood biomass. Researchers at Shenyang Agricultural University in China combined this material with cobalt salts and a nitrogen-rich compound to create a porous carbon structure embedded with cobalt particles and nitrogen functional groups.
This yields a material with many active catalytic sites, which performs particularly well in the so-called oxygen reduction reaction. This is a crucial step in fuel cells and metal-air batteries, where oxygen from the air is converted into water to generate electrical current. The efficiency of this process largely determines how well a fuel cell works, and this is precisely where the bottleneck lies in the scaling up of clean energy technologies.
Comparable performance to platinum, at a fraction of the cost
The measured performance of the new catalyst is impressive. The catalyst retains more than 92 percent of its activity after prolonged use and, moreover, exhibits strong resistance to interference by methanol, a property that is important for use in practical conditions. The researchers also determined that the reaction proceeds via the most desirable mechanism, in which oxygen is directly converted into water without harmful intermediates.
The material thus performed comparably to many advanced platinum-based catalysts, but is composed of abundantly available and renewable raw materials.
Structure and chemistry as the key
The good performance can be explained by the specific structure of the material. The biochar framework creates a hierarchical pore system that improves the supply of molecules and prevents the clumping of metal particles. The nitrogen groups in the material increase oxygen adsorption and electron transport. The cobalt compounds further contribute to the catalytic action through synergistic interaction.
Applications beyond fuel cells
In addition to fuel cells and metal-air batteries, the researchers see potential applications for this approach in hydrogen production and CO₂ reduction. The use of biomass as a starting material aligns with broader objectives regarding carbon-neutral technologies and circular raw material systems.
Follow-up research focuses on improving performance in acidic conditions and exploring other biomass sources to further increase scalability.
Source: Eurek Alert!
Image by Wayne Jackson from Pixabay
