Related Experiment Video
Updated: Sep 28, 2025
05:34
Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes
Published on: December 16, 2019
8.0K
Mechanistic insights into benzene oxidation over CuMn2O4 catalyst
Liming Zhao1, Yingju Yang1, Jing Liu1
1State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Journal of Hazardous Materials
|April 1, 2022
Summary
This study reveals the benzene oxidation mechanism over CuMn2O4 catalysts using DFT. The Cu-terminated surface is more active, with phenoxy group oxidation via the cyclopentadienyl channel being the rate-determining step.
Area of Science:
- Heterogeneous Catalysis
- Surface Science
- Computational Chemistry
Background:
- Spinel-type CuMn2O4 catalysts show promise for benzene oxidation.
- The detailed catalytic oxidation mechanism remains unestablished.
- Understanding the mechanism is crucial for catalyst optimization.
Purpose of the Study:
- To elucidate the reaction mechanism of benzene catalytic oxidation over CuMn2O4.
- To identify active sites and key reaction pathways.
- To determine the rate-determining step using theoretical calculations.
Main Methods:
- Density Functional Theory (DFT) calculations were employed.
- Benzene adsorption on Cu- and Mn-terminated CuMn2O4 surfaces was investigated.
- Reaction pathways, intermediates, and energy barriers were analyzed.
Main Results:
- Benzene adsorption occurs via chemisorption, with the Cu-terminated surface being more active.
- The Cu atom is identified as the primary active site.
- Two main reaction channels (benzoquinone- and cyclopentadienyl-dominated) were identified for phenoxy group oxidation, with the latter being dominant.
- The ring-opening of C5H4O* to C3H2O* (283.45 kJ/mol) is the rate-determining step.
Conclusions:
- The CuMn2O4 catalyst facilitates benzene oxidation through a complex mechanism involving dehydrooxidation and ring-opening.
- The cyclopentadienyl-dominated channel is the preferred pathway for phenoxy group oxidation.
- The identified rate-determining step provides insights for designing more efficient catalysts.
More Related Videos
Related Concept Videos
01:27Benzene to Phenol via Cumene: Hock Process
3.6K
The synthesis of phenol from benzene via cumene and cumene hydroperoxide is called the Hock process. First, a Friedel–Crafts alkylation reaction of benzene with propene gives cumene. Then cumene forms cumene hydroperoxide via a radical chain reaction. In the chain initiation step, the benzylic hydrogen is abstracted to give a benzylic radical. In the chain propagation step, the benzylic radical reacts with an oxygen diradical to form a cumene hydroperoxide radical. The cumene...
3.6K
00:59Reactions at the Benzylic Position: Oxidation and Reduction
4.2K
The benzylic position describes the position of a carbon atom attached directly to a benzene ring. Benzene by itself does not undergo oxidation. In contrast, the benzylic carbon is quite reactive in the presence of strong oxidizing agents such as KMnO4 or H2CrO4. Therefore, alkylbenzenes are readily oxidized to benzoic acid, irrespective of the type of alkyl groups.
4.2K
01:28Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation
5.0K
Unlike the easy catalytic hydrogenation of an alkene double bond, hydrogenation of a benzene double bond under similar reaction conditions does not take place easily. For example, in the reduction of stilbene, the benzene ring remains unaffected while the alkene bond gets reduced. Hydrogenation of an alkene double bond is exothermic and a favorable process. In contrast, to hydrogenate the first unsaturated bond of benzene, an energy input is needed; that is, the process is endothermic. This is...
5.0K
01:18Benzene to 1,4-Cyclohexadiene: Birch Reduction Mechanism
2.3K
Birch reduction uses solvated electrons as reducing agents. The reaction converts benzene to 1,4-cyclohexadiene. The reaction proceeds by the transfer of a single electron to the ring to form a benzene radical anion. This anion is highly basic—it abstracts a proton from the alcohol to form a cyclohexadienyl radical. Another single electron transfer gives the cyclohexadienyl anion. A proton transfer from the alcohol forms 1,4-cyclohexadiene. Since this reduction occurs via radical anion...
2.3K
01:20Electrophilic Aromatic Substitution: Nitration of Benzene
6.7K
The nitration of benzene is an example of an electrophilic aromatic substitution reaction. It involves the formation of a very powerful electrophile, the nitronium ion, which is linear in shape. The reaction occurs through the interaction of two strong acids, sulfuric and nitric acid.
6.7K
01:07Structure of Benzene: Kekulé Model
10.2K
In 1865, August Kekule suggested the structure of benzene according to the structural theory of organic chemistry based on the three assertions—formula of benzene is C6H6, all the hydrogens of benzene are equivalent, and each carbon must have four bonds due to its tetravalency.
He proposed that benzene has a cyclic structure of six carbon atoms attached to one hydrogen atom each, with three alternating pi bonds.
He proposed that benzene has a cyclic structure of six carbon atoms attached to one hydrogen atom each, with three alternating pi bonds.
10.2K