Breaking the production record! Laser and lithium achieve ammonia production under environmental conditions for the first time

The application of laser technology has revolutionized the methods of nitrogen fixation, providing a new method for synthesizing ammonia under environmental conditions. Recently, researchers have used commercial carbon dioxide lasers for the first time to disrupt the nitrogen nitrogen triple bond, providing a new green alternative to the Haber Bosch process.

It is reported that the international research team uses lasers to convert lithium oxide into metallic lithium, which then spontaneously reacts with nitrogen in the air to form lithium nitride. This salt is easily hydrolyzed into ammonia, making the production of this method break historical records.

The new laser based process is more effective in producing ammonia than the traditional Haber Bosch process (Image source: Helmholtz Institute for Renewable Energy)

We have introduced a groundbreaking concept that utilizes high-energy lasers to promote the conversion of various oxides into nitrides, "said Huize Wang, the first author from the Helmholtz Renewable Energy Research Institute in Germany.

He added, "We have achieved unprecedented yields at room temperature and atmospheric pressure. Compared to other methods, this achievement is very significant." The actual yield is two orders of magnitude higher than other state-of-the-art solutions, including electrochemical and mechanochemical methods.

Victor Mougel, an expert in small molecule electrochemical conversion at ETH Zurich, Switzerland, said: "This is a novel method for producing green ammonia, which may be more sustainable compared to the Haber Bosch process. The Haber Bosch process is very energy-efficient and can also lead to carbon dioxide emissions due to its operation at high temperatures and pressures.

In addition, he also stated that the new method "has operational flexibility and environmental benefits" as it works under environmental conditions. This process can also directly generate ammonia where needed, thereby reducing transportation costs.
The team utilizes infrared lasers to provide sufficient energy to dissociate lithium oxygen bonds and generate metallic lithium from lithium oxide. When exposed to air, lithium metal spontaneously combines with nitrogen, breaking the nitrogen nitrogen triple covalent bond and generating lithium nitride.

He further explained, "Next, we hydrolyze the lithium nitride produced by laser to obtain ammonia and lithium hydroxide. In addition, this method provides an opportunity for chemical cycling. Laser can induce the conversion of lithium hydroxide back to lithium nitride, effectively ending the lithium cycle.

He added, "This has also become another new concept - the conversion of hydroxides to nitrides
However, Ivan Stephens, an expert in electrochemistry and nitrogen fixation at Imperial College London in the UK, remains skeptical. He said, "I have doubts about the long-term sustainability of this high yield. Additionally, it is a batch process rather than a continuous process, which greatly limits its feasibility. Compared to new laser induced methods, electrochemical technology can achieve continuous operation, which is a significant advantage.

In addition, the energy demand of lasers may pose problems for expanding ammonia synthesis. He added, "If you only produce ammonia on a small scale as fertilizer in remote areas, then energy efficiency becomes less important.

Researchers propose that their method has significant advantages over electrochemistry, such as desolvation and simplification. In addition, with the expansion of production scale, all emerging ammonia synthesis methods face the greatest challenge. Researchers envision expanding this process by distributing lithium oxide powder on the grid surface and then irradiating the reaction cell array one by one with a laser. In addition, researchers also observed similar behaviors of other oxides, such as magnesium, aluminum, zinc, and calcium, despite their low yields.

He explained, "This may be because other oxides are more difficult to dissociate and hydrolyze." However, the reactivity of alkaline and alkaline earth metals to nitrogen seems promising. He said, "Our recent research has shown that richer metals such as magnesium and calcium can also decompose nitrogen.

Source: OFweek