Related Experiment Video
Updated: Jun 30, 2025

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction
Published on: April 10, 2018
Selective Formation of Cu Active Sites with Different Coordination States on Pseudospinel CuAl2O4 and Their NO
Aoi Okuda1, Taniyuki Furuyama2, Toshiaki Sakai3
1Division of Frontier Engineering, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-Machi, Kanazawa 920-1192, Japan.
Abstract:
In the spinel framework, copper (Cu) in two distinct coordination states exhibits catalytic activity for NO reduction through different mechanisms. However, detailed exploration of their respective catalytic properties, such as the redox behavior of Cu and substrate molecule adsorption, has been challenging due to difficulties in their separate formation. In this study, we present the controlled formation of pseudospinel CuAl2O4, containing exclusively tetrahedrally or octahedrally coordinated Cu, achieved by manipulating aging temperature and O2 concentration. Through these materials, we observed that in the CO-NO reaction, the step primarily determining the rate differs: NO reduction dominates with octahedrally coordinated Cu, whereas carbon monoxide (CO) oxidation is prominent with tetrahedrally coordinated Cu. The lower coordination number of Cu significantly benefits NO reduction but negatively impacts the CO-NO reaction, albeit positively influencing NO reduction in three-way catalytic reactions.
More Related Videos
Related Concept Videos
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
Valence Bond Theory
Extraction: Advanced Methods
Coordination Number and Geometry
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...

