Clean Ammonia Energy Using Photocatalysts – by Rice University
Here’s an article in newsatlas that talks about a photocatalyst developed by Rice University researchers to clean energy from ammonia.
According to the article,
The recent breakthrough by Rice University researchers has the potential to revolutionize clean energy and industrial chemistry. The invention, a small LED-powered device, can convert ammonia into hydrogen efficiently at room temperature, utilizing a cost-effective catalyst made from copper and iron. This discovery could decarbonize the chemical industry and transform how hydrogen is produced and used.
Hydrogen as a Clean Fuel
Hydrogen is a promising clean fuel, usable for combustion or electricity generation in fuel cells. However, handling hydrogen is challenging due to its properties. It is a lightweight gas that needs to be either compressed to 700 atmospheres or cryogenically cooled near absolute zero to liquefy.
Ammonia as a Hydrogen Carrier
Ammonia, consisting of one nitrogen atom bonded to three hydrogen atoms, serves as an excellent hydrogen carrier. It is caustic and hazardous in high concentrations but remains stable at atmospheric temperatures and pressures. Ammonia cracking involves breaking it into hydrogen and nitrogen, a reaction typically requiring temperatures of 650–1,000°C (1,200–1,800°F) and expensive platinum-group metal catalysts like ruthenium.
The Innovative Photocatalyst
The Rice University team developed a photocatalyst that operates at room temperature using copper and iron, which are cheap and abundant metals. The catalyst is part of their “antenna-reactor”
photocatalyst, where light-absorbing “antenna” particles are embedded within the catalyst to facilitate chemical reactions using ambient light or low-energy LEDs. This technology builds on their earlier work on plasmonic photocatalysts, nanoparticles that generate “hot electrons” when exposed to light, driving chemical reactions efficiently at ambient temperatures.
Efficient Ammonia Cracking
The novel photocatalyst, composed of iron and copper, was tested using laser-supplied light in a small experimental setup. The results showed similar efficiency to the more expensive copper-ruthenium thermal catalysts. The photocatalyst was then scaled up to a 500-times larger test rig using LED lighting, retaining its efficiency.
Syzygy Plasmonics and Commercialization
The breakthrough has been commercialized by Syzygy Plasmonics, a company co-founded by Naomi Halas, one of the researchers. Their prototype, called the Rigel Photocatalytic Reactor, is about the size of a washing machine and processes around a ton of ammonia daily, with potential for stacking to increase output.
Potential Applications
This technology has wide-ranging implications, such as enabling hydrogen production on electric cargo ships, possibly revolutionizing aviation by allowing for longer flights using hydrogen derived from ammonia, and even serving as a compact device for electric cars, making ammonia a viable alternative fuel.
