Question of the Week, 28.12.2010
Molecular nitrogen is known to be chemically almost inert as it is held together by a strong triple bond. Nonetheless, nitrogen compounds play a crucial role in many commercial processes, e.g., they are essential for the production of fertilizers, pharmaceuticals, and explosives. For almost 100 years now, the main access to nitrogen compounds is provided by the reduction of molecular nitrogen to ammonia via the Haber-Bosch process, which was considered a revolution at the time of its invention and is still one of the most important large-scale chemical processes.
However, many people in science and industry wonder if the time is ripe for another revolution. The Haber-Bosch process requires temperatures of 400-550°C and pressures of 200-300 bar while biological nitrogen fixation takes place at room temperature and pressure with the aid of the nitrogenase enzyme. This fact raises the question if catalytic assistance may be able to drastically lower the insurmountable activation barrier for the formation of ammonia from molecular nitrogen in the industrial process as well. Much research has been conducted on the exploration of the nitrogenase enzyme and the discovery of new catalysts for nitrogen fixation but all novel reactions in this field are far away from being used on a large scale.
Further reading:
Catalysts for Nitrogen Fixation: Nitrogenases, Relevant Chemical Models and Commercial Processes,
edited by: B. E. Smith, R. L. Richards, and W. E. Newton, Springer, 2004.
Thomas Jagau