A photochemical approach to nitrogen fixation has been developed by US researchers, the discovery of a light-activated catalyst for converting nitrogen gas into ammonia could lead to low-cost agricultural fertilizers. "Scientists have been fascinated by the biological enzyme nitrogenase, which catalyzes the [nitrogen fixation] reaction in nature," explains team member Mercouri Kanatzidis of Northwestern University. "Now, we have created a successful mimic of nature's process." The team's catalyst is a porous chalcogel containing clusters of iron, molybdenum and sulfur (FeMoS), the three key chemical components at the heart of the nitrogenase enzyme. In their successful proof of principle experiments, the team concedes that the reaction rate is a thousand times lower than that observed with nitrogenase, but this is an important first step towards a synthetic approach to fixing nitrogen that avoids the high temperatures and pressures of conventional industrial processes.