A team of researchers in China has developed a catalyst capable of transforming nitrate pollution from agricultural runoff and industrial wastewater into ammonia—the essential chemical building block of urea fertiliser—with nearly three times the efficiency of conventional catalysts. The discovery, published on March 18 in the Journal of the American Chemical Society and featured on its cover, signals a potential shift in how waste pollution could be converted into valuable industrial inputs.
At the heart of the breakthrough is a class of materials known as dual-atom catalysts, or DACs. Unlike traditional single-atom catalysts, DACs are built with pairs of metal atoms positioned close together, enabling them to cooperate in driving complex chemical reactions. This paired structure allows them to perform multi-step transformations more efficiently, including the conversion of nitrate into ammonia or even the reduction of carbon dioxide into useful compounds.
Despite their promise, dual-atom catalysts have historically been difficult to design. Their development has largely relied on trial and error, with limited theoretical models to guide the selection of metal combinations. Challenges such as low metal loading and difficulty in stabilising diverse atomic pairs have slowed progress in the field.
To overcome these barriers, Han Lili and her team at the Fujian Institute of Research on the Structure of Matter under the Chinese Academy of Sciences turned to artificial intelligence. Using deep learning techniques, they trained a model to identify metal combinations with high pairing probabilities, allowing the researchers to predict which elements would most effectively form stable dual-atom structures.
Guided by this model, the team engineered 14 distinct catalysts using a range of rare earth elements, including yttrium, scandium, lanthanum, cerium, samarium, europium, erbium, and ytterbium. The resulting materials achieved metal loadings between 12.8 and 30.7 percent by weight, more than four times higher than previous benchmarks for similar catalysts. This dense concentration of active sites significantly enhances their chemical performance.
When applied to nitrate-rich wastewater, the catalysts demonstrated a marked increase in efficiency. The abundance of active metal sites enabled a sharp boost in ammonia production, reaching 2.7 times the output of conventional catalysts under similar conditions. Researchers say this improvement could make electrochemical nitrate reduction a far more viable industrial process.
The environmental implications are significant. Nitrate pollution from fertiliser runoff and industrial discharge is a major contributor to water contamination, often leading to harmful algal blooms and oxygen-depleted “dead zones” in rivers and coastal ecosystems. Converting this pollutant into ammonia offers a dual benefit: cleaning wastewater while producing a valuable chemical feedstock.
Ammonia itself is a critical intermediary in the production of urea, the world’s most widely used nitrogen fertiliser. Today, most urea is manufactured through the Bosch-Meiser process, which combines ammonia with carbon dioxide under high pressure and temperature. This process is heavily dependent on natural gas, making global fertiliser production vulnerable to energy price fluctuations and geopolitical disruptions.
Those vulnerabilities have become increasingly visible in recent years. Much of the global urea trade flows through the Middle East, where supply routes can be affected by instability around key chokepoints such as the Strait of Hormuz. Disruptions in these supply chains can quickly translate into higher fertiliser prices worldwide, affecting agricultural costs and food security.
China’s state broadcaster CCTV recently highlighted the volatility of global markets, noting that India, the world’s second-largest importer of urea, was forced in April to purchase 2.5 million tonnes at nearly double the price it had paid just two months earlier. Such swings underscore the fragility of global fertiliser supply chains in times of geopolitical tension.
China itself has maintained relatively stable domestic fertiliser production through a different industrial pathway. Instead of relying on natural gas, it primarily uses coal-based processes in which coal, steam, and nitrogen are converted into ammonia and carbon dioxide under high-temperature, high-pressure conditions. These are then processed into urea at scale, allowing China to buffer itself against some external energy shocks.
However, both coal- and gas-based routes remain highly energy-intensive. This is where the new catalyst research could become strategically important. By enabling the production of ammonia directly from nitrate pollution at room temperature, the technology offers a potential low-energy alternative that could complement existing industrial systems.
Researchers caution that the innovation is not expected to replace large-scale fertiliser plants in the near term. Instead, it could serve as a distributed or supplementary technology, capable of turning waste streams into usable chemical resources while easing pressure on conventional production systems.
Beyond its industrial applications, the study also reflects a broader trend in materials science: the increasing use of artificial intelligence to accelerate chemical discovery. By replacing slow experimental screening with predictive modelling, researchers are able to explore far larger combinations of elements and structures than previously possible.
The visual representation of the catalyst in the Journal of the American Chemical Society—depicting metal atoms orbiting a central point like planets in a solar system—captures both the scientific elegance and complexity of the design. It also reflects a growing convergence of computational science and chemistry, where data-driven models are reshaping how materials are conceived.
While still at an early stage, the development points toward a future in which pollution itself could become a resource stream rather than a waste problem. In a global economy increasingly shaped by supply chain vulnerabilities and energy transitions, such technologies may play a growing role in stabilising critical inputs like fertiliser.
