New Study Reveals Spontaneous Formation of Urea: Implications for Origin of Life

In a groundbreaking study, researchers from ETH Zurich have discovered a previously unknown reaction pathway for the spontaneous formation of urea from carbon dioxide (CO₂) and ammonia (NH₃) on aqueous surfaces. This finding, which could have significant implications for understanding the origins of life on Earth, was published in the journal *Science* on July 2, 2025, under the leadership of Professor Ruth Signorell, a prominent figure in physical chemistry at the institution.

Urea, a molecule that plays a crucial role as a building block for biological molecules such as RNA and DNA, is produced industrially through energy-intensive methods that typically require high temperatures, pressures, or chemical catalysts. However, the new research suggests that urea can form under ambient conditions, where water molecules interact with ambient atmospheric gases, specifically on the surface of tiny water droplets. This process not only provides insights into prebiotic chemistry but also suggests potential avenues for sustainable urea production.

According to Professor Signorell, "In our study, we show one way in which urea could have formed on the prebiotic Earth, namely where water molecules interact with atmospheric gases: on the water surface." The research indicates that the interfacial layer of water droplets creates a unique chemical environment that facilitates this spontaneous reaction.

The research team studied water droplets similar to those found in mist or sea spray, noting that the high surface area-to-volume ratio of droplets means that chemical reactions predominantly occur at the surface. Mercede Mohajer Azizbaig, one of the study's lead authors, explained, "The remarkable aspect of this reaction is that it takes place under ambient conditions without any external energy."

This finding offers a window into possible prebiotic conditions on early Earth, suggesting that aqueous aerosols or fog droplets may have acted as natural reactors for forming precursor molecules like urea. Theoretical calculations by co-authors Evangelos Miliordos and Andrei Evdokimov from Auburn University corroborated the experimental observations, confirming that the formation of urea can occur without external energy inputs.

The implications of this research extend beyond mere academic interest; they touch upon the potential for developing greener methods for urea synthesis, a chemical essential for fertilizers and various industrial applications. As the world grapples with climate change and seeks sustainable practices, understanding how urea can be produced naturally could inform future industrial processes.

The research adds to a growing body of work exploring the origins of life on Earth, a topic that remains contentious and multifaceted. As scientists continue to unravel the complexities of how life began, this study highlights the importance of seemingly mundane chemical interactions in shaping the biochemical landscape of early Earth. "Our study shows how seemingly mundane interfaces can become dynamic reaction spaces, suggesting that biological molecules may have a more common origin than was previously thought," Signorell concluded.

As the field of origin-of-life studies progresses, further exploration is necessary to understand the full implications of these findings and how they may reshape our understanding of the chemical precursors to life in a primordial context. The research is expected to inspire additional studies into the environmental conditions that may have facilitated similar reactions on early Earth, as well as potential applications in sustainable chemistry and industrial practices.