Local structures and catalytic N₂O decomposition properties of Ni_1-xCu_xCo₂O₄

Area of Science:

• Materials Science
• Catalysis
• Environmental Chemistry

Background:

• Nitrous oxide (N2O) is a potent greenhouse gas with significant environmental impact.
• Effective catalytic decomposition of N2O is crucial for emissions control.

Purpose of the Study:

• To investigate the catalytic performance of Ni1-xCuxCo2O4 spinel oxides for direct N2O decomposition.
• To understand the structure-activity relationships governing N2O conversion.

Main Methods:

• Synthesis of Ni-Cu-Co spinels via controlled precipitation.
• Characterization using XRD, BET, XPS, and H2-TPR.
• Catalytic activity testing under controlled gas conditions with and without water vapor.

Main Results:

• Partial substitution of Ni by Cu in Ni-Cu-Co spinels enhances N2O decomposition activity.
• Ni0.75Cu0.25Co2O4 demonstrated the highest catalytic performance, achieving nearly complete N2O decomposition at ~400°C.
• Cu substitution modified redox properties and oxygen vacancy concentration, key factors for enhanced activity.

Conclusions:

• Ni-Cu-Co spinel oxides are effective catalysts for N2O decomposition.
• Cobalt-oxygen vacancy pairs are identified as the main active sites.
• Nickel and copper play crucial roles in modulating electronic structure and oxygen mobility for improved catalysis.