What makes manganese diboride 150% better than aluminum fuel?

University at Albany chemists have developed a rocket fuel compound, manganese diboride (MnB₂), that delivers approximately 150% more energy by volume than aluminum, the current standard in solid rocket boosters.

This breakthrough promises lighter and more efficient spacecraft, enabling the transport of additional payloads while using less fuel.

Manganese diboride, which has an exceptional energy density, marks a significant advance in materials chemistry for space exploration, as published recently in the Journal of the American Chemical Society.

How does manganese diboride outperform aluminum as rocket fuel?

Manganese diboride offers a gravimetric heat of combustion of 39.26 kJ/g and a volumetric heat of combustion of 208.08 kJ/cm³.

Compared to aluminum metal used in Space Shuttle boosters and NASA's Space Launch System, MnB₂ delivers 26% more energy by weight and 148% more by volume.

This volumetric energy density is the highest recorded for any known solid fuel.

Did you know?
Manganese diboride has the highest known volumetric energy density of any solid fuel, surpassing even traditional aluminum metal fuels.

What are the unique features of manganese diboride, called MnB₂?

The compound's extraordinary energy comes from its molecular structure. Computational models reveal that MnB₂ has hexagonal patterns that are slightly skewed or "deformed," which store potential energy similarly to a compressed spring. This subtle deformation is key to its energy storage capabilities.

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University breakthroughs in high-energy rocket fuels

Synthesizing manganese diboride required overcoming technical challenges. The research team used an "arc melter" to heat manganese and boron powders to 3,000°C, then rapidly cooled the molten material to lock its unstable structure.

This precise method ensures the unique molecular deformation is preserved long enough for practical use.

The synthesis and safety of manganese diboride fuel

Despite its high energy content, manganese diboride is stable under open flame exposure and requires an ignition agent like kerosene to burn. It also remains stable in air and humidity for over two weeks.

However, concerns about the toxicity of boron oxide when burned suggest its best applications might be limited to space environments rather than Earth-based uses.

This research boosts rocket fuel technology and hints at broader uses for boron-based compounds in industries like automotive catalytic converters and plastic recycling catalysts.

The breakthrough at the University at Albany underscores the importance of innovative chemistry in advancing space exploration.