Single-Cation Catalyst: Ni Cation in Monolayered CuO for CO Oxidation

Area of Science:

• Heterogeneous Catalysis
• Surface Chemistry
• Nanomaterials

Background:

• Distinguishing catalytic behaviors of single-atom species is critical.
• Understanding supported single-metal cations is important in catalysis.

Purpose of the Study:

• To differentiate catalytic properties between cationic and metallic single nickel atoms.
• To investigate the reaction mechanisms of CO oxidation over these distinct Ni species.

Main Methods:

• Fabrication of well-defined cationic Ni atoms and metallic Ni atoms on monolayered CuO.
• In-situ characterization and kinetic studies of CO oxidation reactions.

Main Results:

• Cationic Ni atoms are inert to CO adsorption but active for O2 dissociation.
• Metallic Ni atoms on CuO support follow the Mars-van Krevelen mechanism for CO oxidation.
• Cationic Ni atoms facilitate CO oxidation via the Eley-Rideal mechanism.

Conclusions:

• Single cationic Ni atoms exhibit unique catalytic activity distinct from metallic Ni.
• The Eley-Rideal mechanism for CO oxidation over cationic Ni provides new insights into supported single-metal cation chemistry.