The researchers have discovered that manganese, an abundant and low-cost metal, can effectively convert carbon dioxide into formate, a potential source of hydrogen for fuel cells. The key was an ingenious redesign that allows the catalyst to work much longer than other similar low-cost materials. Surprisingly, the improved manganese catalyst even outperforms many precious metal-based catalysts. This finding could enable the transformation of greenhouse gases into ingredients for clean energy.
New Research
Scientists have found a low-cost method to convert carbon dioxide into a valuable precursor of clean energy using manganese, a common element.
A new study by scientists from Yale and Missouri universities shows that manganese-based catalysts can efficiently convert carbon dioxide into formate. Manganese is abundant and cheap, making it an ideal substitute for expensive metals. Formate is considered a promising material for hydrogen storage and could power the next generation of fuel cells. The research was published in the journal Chem.
Why Hydrogen Fuel Cells Are Important
Hydrogen fuel cells work similarly to batteries, converting the chemical energy of hydrogen into electricity. Although this technology is promising for clean energy, its widespread adoption is limited by the difficulty and high cost of producing and storing hydrogen efficiently.
“The utilization of CO₂ is now a priority as we seek renewable chemical raw materials to replace those derived from fossil fuels,” said Hazari, John Randolph Hoffman Professor of Chemistry and chair of the chemistry department at Yale’s Faculty of Arts and Sciences (FAS).
Formate as a Hydrogen Carrier
Formic acid, the protonated form of formate, is currently produced on an industrial scale. It is commonly used as a preservative, antibacterial agent, and leather tanning agent. Many scientists believe that if it could be produced sustainably and efficiently, formic acid could also serve as a practical source of hydrogen for fuel cells.
Currently, most industrial production of formate relies on fossil fuels, limiting its long-term environmental benefits. Researchers claim that a cleaner alternative would be to produce formate directly from carbon dioxide in the air. This approach would reduce greenhouse gas emissions and generate useful chemicals.
The Challenge of Catalysts
Converting carbon dioxide into formate requires a catalyst, which has been a major hurdle. Many of the most effective catalysts developed so far rely on precious metals, which are expensive, scarce, and often toxic. More abundant metals tend to break down, reducing their ability to catalyze the chemical reaction.
How Manganese Exceeded Expectations
The research team developed a new strategy to overcome this problem. By redesigning the structure of the catalyst, they managed to significantly increase the lifespan of manganese-based catalysts. As a result, these catalysts outperformed most precious metal catalysts.
The researchers say the key improvement was the addition of an extra donor atom in the ligand design (ligands are atoms or molecules that bind to the metal atom and influence its reactivity). This change helps stabilize the catalyst and maintain its effectiveness.
