Ammonia is one of the unsung heroes of modern civilization. Without it, the world’s agricultural productivity would be a fraction of what it is today, and billions of people would starve. Yet, ammonia’s current production — predominantly through the Haber-Bosch process — comes at a steep environmental cost.

Almost 2% of the energy that humankind uses goes to ammonia production, which contributes significantly to greenhouse gas emissions. Now, an innovative breakthrough offers a promising path toward producing ammonia sustainably, harnessing nothing but air, water vapor, and a clever catalyst.

Going beyond the Haber Process

Ammonia (NH₃) is a great candidate for the “most impactful substance” in our society. It’s simply critical for our way of life, supporting global agriculture. Without it, we wouldn’t be able to feed over half the world’s population. Beyond farming, ammonia is used in pharmaceuticals, cleaning products, and even as a potential energy carrier for renewable fuels. The global production of ammonia exceeds 183 million metric tons annually — and this demand is only expected to rise.

The conventional Haber-Bosch process, invented in the early 20th century, transformed ammonia production. But it’s not without drawbacks. The process requires temperatures between 350°C and 450°C and pressures as high as 200 atmospheres. This energy-intensive method accounts for 2% of global energy consumption and 5% of natural gas use. And the carbon dioxide emissions are staggering, contributing to nearly 1% of the world’s total greenhouse gas output.

Clearly, a greener alternative is desperately needed. That’s where this new research steps in.

The team, led by Stanford’s Xiaowei Song, Chanbasha Basheer, and Richard N. Zare, has developed a process that synthesizes ammonia directly from nitrogen in the air and water vapor. What makes this method revolutionary is its simplicity and sustainability. Unlike the Haber-Bosch process, this approach works at room temperature and atmospheric pressure, without the need for large-scale facilities.

How it works

The core of the technology is a catalyst mesh composed of magnetite (Fe₃O₄) and a polymer called Nafion. When air passes through the catalyst, tiny water droplets condense and interact with nitrogen gas, producing ammonia. This happens through a process called contact electrification, where the interaction of water, nitrogen, and the catalyst generates the energy needed to break nitrogen’s triple bond and form ammonia.

“This breakthrough allows us to harness the nitrogen in our air and produce ammonia sustainably,” said study senior author Richard Zare, the Marguerite Blake Wilbur Professor in Natural Science and professor of chemistry in the Stanford School of Humanities and Sciences. “It’s a significant step toward a decentralized and eco-friendly approach to agriculture.”

It’s decentralized because unlike current ammonia manufacturing plants, which are large-scale, this can be done in smaller batches without the need for big facilities.

Zare and colleagues analyzed factors such as humidity, wind speed, salt levels, and acidity to optimize production.

In controlled experiments, the researchers achieved ammonia concentrations ranging from 25 to 120 micromoles (or 0.43 to 2.04 milligrams) per liter within an hour, depending on humidity levels. With further optimization, they scaled up the process to produce concentrations as high as 270 micromoles (or 4.6 milligrams) per liter within two hours — all this for much less energy than the conventional process.

It also works in the real world — but scaling is tricky

As Zare mentions, one of the most exciting aspects of this discovery is its potential for decentralization. The team has designed a portable device for onsite ammonia production. This device uses a suction pump to draw in air, ensuring a steady supply of nitrogen and water vapor. A cooling plate condenses the ammonia-enriched solution, making it easy to collect and use immediately. The team demonstrated this device in real-world conditions.

For farmers in remote or developing regions, this could be a game-changer. Instead of relying on centralized ammonia production facilities and the complex logistics of transporting fertilizers, farmers could produce ammonia directly in the field. This would reduce costs, emissions, and logistical hurdles.

But it has its own limitations. Firstly, the rate of production is pretty low.

The current ammonia production rates are suitable for small-scale applications, but meeting the demands of large-scale agriculture or industry will require further advancements. The catalyst mesh and system design need optimization to improve efficiency and output.

Secondly, it’s not clear how durable the catalyst is. Wear and degradation over time could hinder the long-term viability of the system. Lastly, in regions with low humidity or inconsistent weather conditions, the process might underperform or require additional water sources.

Still, researchers are confident.

The ammonia concentrations produced by the device are sufficient for certain agricultural applications, such as seedling fertilization or hydroponic systems. For larger-scale farming, the device could be paired with additional technologies to further concentrate the ammonia.

A couple of years from market-ready

The device is just 2-3 years away from being ready to hit the market, says co-author Chanbasha Basheer of King Fahd University of Petroleum and Minerals. In the meantime, there’s a lot to work on, a plenty of room to improve the technology, says Basheer.

If successfully scaled, this technology could significantly reduce the environmental impact of ammonia production. By eliminating the need for high temperatures, high pressures, and fossil fuels, this method offers a path toward a greener, more sustainable future.

While there’s still a great deal of work to be done, this breakthrough offers a glimpse of a future where ammonia production is cleaner, greener, and more accessible to all. In the fight against climate change, every step toward sustainability counts — and this promises to be a big one.

“Green ammonia represents a new frontier in sustainability,” Zare said. “This method, if it can be scaled up economically, could drastically reduce our reliance on fossil fuels across multiple sectors.”

The study was published in Scientific Reports.