Related Experiment Video
Updated: Sep 22, 2025

Covalent Immobilization of Proteins for the Single Molecule Force Spectroscopy
Published on: August 20, 2018
Breaking the Linear Relation in the Dissociation of Nitrogen on Iron Surfaces
Dexin Liu1, Wei Zhao1, Qinghong Yuan1,2
1State Key Laboratory of Precision Spectroscopy, School of Physics and Electronic Science, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China.
Abstract:
Current industrial ammonia synthesis depends on the Haber-Bosch process, in which the activity of the catalyst is limited by the Brønsted-Evans-Polanyi (BEP) principle and Fe is used as a commercial catalyst. Herein, we found that the dissociation barriers of N2 on Fe(111), Fe(211), Fe(110), and Fe(100) surfaces do not follow the widely accepted BEP principle. N2 dissociation on Fe(111) surface has the smallest adsorption energy and the lowest energetic barrier. Such an abnormal phenomenon can be attributed to charge transfer from Fe surfaces to the anti-bonding orbital (π*) of the absorbed N2 . More charges transferred from the Fe surface to π* of N2 leads to a weaker N≡N triple bond and a lower adsorption energy of N atoms. However, the hydrogenation of N atoms and desorption of NH3 on the four Fe surfaces follow the BEP principle. Therefore, Fe(111) is found to be the most active surface to promote ammonia synthesis, and such a conclusion is also applicable to Ni and Mo surfaces.
Related Concept Videos
Radical Formation: Homolysis
Formation of Complex Ions
Complexation Equilibria: Overview
The equilibrium constant of the complexation reaction is represented as the formation constant...
Covalent Bonding and Lewis Structures
Mass Spectrometry: Amine Fragmentation
In amines, the number of nitrogen atoms affects the mass of the molecular ion, which is described by the nitrogen rule of mass spectrometry. This rule states that a compound containing...
Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)
