Renewable approach to synthesizing ammonia using single-atom catalysts

Ammonia, a compound of nitrogen and hydrogen, is an essential chemical for fertilizers, pharmaceuticals and renewable energy. Currently, the costly and environmentally harmful Haber-Bosch process is used to synthesize ammonia from fossil fuels.

Endeavors to replace this energy-consuming method emphasized the use of renewable sources. These approaches, such as the electrosynthesis of ammonia from nitrogen species using renewable electricity, represents a promising and significant alternative.

Li et al. present the recent progress made in ammonia electrosynthesis using single-atom catalysts, highlighting a method that could supersede the Haber-Bosch process to offer important environmental, sustainable and energy benefits. Single-atom catalysts are atomically dispersed metal catalysts on solid supports, capable of achieving the combined advantages of heterogeneous and homogenous catalysts.

“Single-atom catalysts, which have gained prominence as a powerful platform for energy and chemical conversion, can enable the electrification of ammonia synthesis,” said author Guihua Yu. “Ammonia electrosynthesis from the reduction of different nitrogen species, such as molecular dinitrogen, nitrogen oxides and nitrates ions, is significant and important.”

Current ammonia manufacturing consumes roughly 2% of annual energy and emits above 1% of global greenhouse emissions. Synthesizing ammonia from electrochemical nitrogen reduction reactions can utilize electricity from renewable solar and wind sources.

The development of sustainable ammonia synthesis may have a similar groundbreaking effect on the large-scale global economy as the Haber-Bosch process did a century ago.

“Continuing ammonia supplies to nourish a dramatically growing population nowadays has raised serious environmental concerns because of the primary use of fossil fuels for hydrogen production,” said Yu. “We must take effective action to face the substantial challenges of climate change.”

Source: “Ammonia electrosynthesis on single-atom catalysts: Mechanistic understanding and recent progress,” by Panpan Li, Zhiwei Fang, Zhaoyu Jin, and Guihua Yu, Chemical Physics Reviews (2021). The article can be accessed at https://doi.org/10.1063/5.0069736 .