Related Experiment Video
Updated: Aug 19, 2025

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction
Published on: April 10, 2018
N2 Reduction versus H2 Evolution in a Molybdenum- or Tungsten-Based Small-Molecule Model System of Nitrogenase
Jannik Junge1, Tobias A Engesser1, Felix Tuczek1
1Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Strasse 2, 24118, Kiel, Germany.
Abstract:
Molybdenum dinitrogen complexes have played a major role as catalytic model systems of nitrogenase. In comparison, analogous tungsten complexes have in most cases found to be catalytically inactive. Herein, a tungsten complex was shown to be supported by a pentadentate tetrapodal (pentaPod) phosphine ligand, under conditions of N2 fixation, primarily catalyzes the hydrogen evolution reaction (HER), in contrast to its Mo analogue, which catalytically mediates the nitrogen-reduction reaction (N2 RR). DFT calculations were employed to evaluate possible mechanisms and identify the most likely pathways of N2 RR and HER activities exhibited by Mo- and W-pentaPod complexes. Two mechanisms for N2 RR by PCET are considered, starting from neutral (M(0) cycle) and cationic (M(I) cycle) dinitrogen complexes (M=Mo, W). The latter was found to be energetically more favorable. For HER three scenarios are treated; that is, through bimolecular reactions of early M-Nx Hy intermediates, pure hydride intermediates or mixed M(H)(Nx Hy ) species.
More Related Videos
10:01Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase
Published on: December 4, 2017
08:40Synthesis of Metal Nanoparticles Supported on Carbon Nanotube with Doped Co and N Atoms and its Catalytic Applications in Hydrogen Production
Published on: December 6, 2021
Related Concept Videos
Nitriles to Amines: LiAlH4 Reduction
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
Preparation of Amines: Reduction of Oximes and Nitro Compounds
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
Electrophilic Aromatic Substitution: Nitration of Benzene
Rate-Determining Steps
In a multistep reaction mechanism, one of the elementary steps progresses significantly slower than the others. This slowest step is called the rate-limiting step (or rate-determining step). A reaction cannot proceed faster than its slowest step, and hence, the rate-determining step limits the overall reaction rate.
The concept of rate-determining step can be understood from the analogy of a 4-lane freeway with a short-stretch of traffic-bottleneck caused due to...
meta-Directing Deactivators: –NO2, –CN, –CHO, –⁠CO2R, –COR, –CO2H
Inorganic Nitrogen Assimilation