Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Catalysis

Catalysis

The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.

Cycloaddition Reactions: MO Requirements for Photochemical Activation

Cycloaddition Reactions: MO Requirements for Photochemical Activation

Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.

Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide

Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide

Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.

Olefin Metathesis Polymerization: Overview

Olefin Metathesis Polymerization: Overview

Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists...

Thermal Electrocyclic Reactions: Stereochemistry

Thermal Electrocyclic Reactions: Stereochemistry

The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.

Photochemical Electrocyclic Reactions: Stereochemistry

Photochemical Electrocyclic Reactions: Stereochemistry

The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Linking metal oxidation to oxygen reactivity.

Nature materials·2026

Same author

Synergistic surface modification of Cu with schiff-base networks for high selectivity and durability in CO<sub>2</sub>-to-C<sub>2</sub>H<sub>4</sub> electroreduction.

Nature communications·2026

Same author

Author Correction: Manipulating d-orbital of Cu single atom site by coordination engineering for selective oxidation of benzene.

Nature communications·2026

Same author

Charge accumulation and solvation in β-NiOOH: Surface chemistry of an OER catalyst from ML-aided simulations.

The Journal of chemical physics·2026

Same author

Development of a boron-doping strategy to activate luminescence in a non-emissive silver-incorporated polyoxoniobate.

Dalton transactions (Cambridge, England : 2003)·2025

Same author

In Situ Visualization of Lattice-Coherent Phase Oscillations and Active Brownian Motion of a Copper Catalyst During Hydrogen Oxidation.

Angewandte Chemie (International ed. in English)·2025

Search research articles

Related Experiment Video

Updated: May 25, 2025

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst

Published on: May 21, 2019

Operando TEM study of a working copper catalyst during ethylene oxidation.

Wenqian Yu^1,2, Shengnan Yue^1,2, Minghe Yang^1,2

¹College of Chemistry, Fuzhou University, Fuzhou, China.

Nature Communications

|February 27, 2025

Summary

Studying copper catalysts during ethylene oxidation reveals distinct structural and selectivity regimes. Operando TEM shows how catalyst state under reaction conditions dictates ethylene oxide formation, challenging previous assumptions.

More Related Videos

Synthesis and Testing of Supported Pt-Cu Solid Solution Nanoparticle Catalysts for Propane Dehydrogenation

Synthesis and Testing of Supported Pt-Cu Solid Solution Nanoparticle Catalysts for Propane Dehydrogenation

Published on: July 18, 2017

Tuning the Acidity of Pt/ CNTs Catalysts for Hydrodeoxygenation of Diphenyl Ether

Tuning the Acidity of Pt/ CNTs Catalysts for Hydrodeoxygenation of Diphenyl Ether

Published on: August 17, 2019

Related Experiment Videos

Last Updated: May 25, 2025

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst

Published on: May 21, 2019

Synthesis and Testing of Supported Pt-Cu Solid Solution Nanoparticle Catalysts for Propane Dehydrogenation

Synthesis and Testing of Supported Pt-Cu Solid Solution Nanoparticle Catalysts for Propane Dehydrogenation

Published on: July 18, 2017

Tuning the Acidity of Pt/ CNTs Catalysts for Hydrodeoxygenation of Diphenyl Ether

Tuning the Acidity of Pt/ CNTs Catalysts for Hydrodeoxygenation of Diphenyl Ether

Published on: August 17, 2019

Area of Science:

Materials Science
Catalysis
Surface Chemistry

Background:

Active catalysts are metastable, with surface states influenced by gas-phase conditions and kinetics.
Understanding structure-performance relationships requires studying catalysts under operational conditions.

Purpose of the Study:

To investigate the structure-performance relationships of a copper catalyst during ethylene oxidation.
To elucidate reaction pathways and identify different catalytic regimes under operando conditions.

Main Methods:

Operando transmission electron microscopy (TEM) for real-time structural observations.
Online mass spectrometry (MS) to monitor reaction products.
Theoretical calculations to aid in pathway elucidation.

Main Results:

Identified three distinct temperature-dependent regimes with varying Cu structures (Cu2O, Cu0/Cu2O oscillation, Cu0).
Low temperatures: Quasi-static Cu2O selective for ethylene oxide (EO) and acetaldehyde (AcH) via oxometallacycle pathway.
Medium temperatures: Dynamic Cu0/Cu2O oscillation regime with reduced activation energies.
High temperatures: Predominantly Cu0 with monolayer Cu2O favors direct EO formation, while Cu0 promotes combustion.

Conclusions:

Catalyst structure and state under operando conditions are critical for selectivity in ethylene oxidation.
Findings challenge prior conclusions from ultra-high vacuum studies regarding metallic copper's epoxidation selectivity.
Emphasizes the necessity of operando studies for accurate catalyst characterization and performance evaluation.