Professor Ping Chen and Professor Jianping Guo from our research group were recently invited by Nature Catalysis to write a retrospective article titled "Ammonia History in the Making." The article highlights the significant contributions of Professor Gerhard Ertl, the 2007 Nobel Prize winner in Chemistry, to the catalysis of synthetic ammonia.

Gerhard Ertl is one of the pioneers of modern surface science research. He and his collaborators used surface science methods to conduct a systematic and in-depth study of the ammonia synthesis reaction on the surface of iron single crystalas amodel catalyst, revealing the mechanism of nitrogen activation and ammonia generation at the molecular level, and forming a universal view on the catalysis of ammonia synthesis that continues until today. This perspective article outlines the understanding of basic scientific issues such as nitrogen dissociation mode, catalyst structure sensitivity, elementary reaction potential, and alkali metal promotion mechanism based on surface science research; and further looks forward to the development trend of chemical nitrogen fixation research.

In recent years, research on nitrogen conversion has shown a new development trend, especially "green synthetic ammonia driven by renewable energy" is a cutting-edge topic in this research field. In terms of thermal catalysis, since the energy required for direct dissociation of nitrogen molecules on traditional transition metal catalysts and subsequent hydrogenation into ammonia is relatively high, the next step of research should be to explore new modes of activation and conversion of nitrogen molecules and new concepts for catalyst design to overcome the difficult problem of "efficient synthesis of ammonia under mild conditions". The use of light, electricity, plasma, chemical looping and other methods has added new dimensions to the synthesis of ammonia and contains new opportunities. In addition to ammonia, the synthesis of compounds containing NX (X=H, C, O, etc.) bonds from nitrogen is an emerging and extremely challenging basic research topic in recent chemical nitrogen fixation research. The rapid development of surface science in in situ detection and visual characterization of catalysts can also further contribute to the new direction of nitrogen fixation research.

In recent years, Professor Chen's team has been committed to the research of nitrogen activation and conversion, and has constructed a new system of alkali (earth) metal hydride-transition metal ammonia synthesis catalysts (Nat. Chem., 2017; Angew. Chem. Int. Ed., 2017; J. Am. Chem. Soc., 2018), and explored a new process of low-temperature chemical looping ammonia synthesis using metal hydrides and imino compounds as nitrogen carriers, providing ideas for the development of new processes and new materials for ammonia synthesis based on renewable energy (Nat. Energy, 2018). (Text/Photo by Guo Jianping)

Article link: https://doi.org/10.1038/s41929-021-00676-0