Disentangling Local Interfacial Confinement and Remote Spillover Effects in Oxide-Oxide Interactions

Area of Science:

• Catalysis
• Materials Science
• Surface Chemistry

Background:

• Supported oxides are crucial in catalytic reactions.
• Understanding oxide-oxide interface interactions is key but challenging.

Purpose of the Study:

• To investigate the impact of different oxide-oxide interfaces on catalytic performance.
• To elucidate the mechanisms behind interfacial effects in CO2 hydrogenation.

Main Methods:

• Chemically depositing Cobalt oxide (Co3O4) onto Zinc Oxide (ZnO) to create a bonded interface (Co3O4/ZnO).
• Mechanically mixing Co3O4 and ZnO to form a physically contacted interface (Co3O4-ZnO).
• Evaluating catalytic activity and selectivity in CO2 hydrogenation reactions.

Main Results:

• The chemically bonded Co3O4/ZnO interface impeded Co3O4 reduction, maintaining a metastable CoO state and achieving 93% CO selectivity in CO2 hydrogenation.
• The physically contacted Co3O4-ZnO interface promoted Co3O4 reduction to Co0, leading to 45% CO2 conversion and 92% CH4 selectivity.
• Remote spillover of dissociated hydrogen from ZnO to Co oxide nanoparticles was identified as the mechanism for the physically contacted interface.

Conclusions:

• Distinct oxide-oxide interactions (chemically bonded vs. physically contacted) exert opposing effects on catalytic performance.
• Local interfacial confinement stabilizes catalytic states, while remote spillover influences reaction pathways.
• This study highlights the critical role of interface engineering in designing advanced oxide-oxide catalytic systems.