Surface-strain-enhanced oxygen dissociation on gold catalysts

Area of Science:

• Catalysis
• Materials Science
• Surface Chemistry

Background:

• Nanogold catalysts exhibit remarkable low-temperature oxidation performance and stability.
• The precise active source responsible for gold's low-temperature oxidation remains unclear.
• Understanding this mechanism is crucial for advancing catalytic applications.

Purpose of the Study:

• To elucidate the primary active source in the low-temperature oxidation of gold catalysts.
• To investigate the role of catalyst surface reconstruction and strain in oxidation reactions.
• To provide insights into designing improved gold catalysts for nitrogen activation.

Main Methods:

• In situ electron microscopy and mass spectrometry were employed to monitor reactions.
• Catalyst surface strain was analyzed using advanced techniques.
• First-principles calculations were utilized to model surface interactions and reaction pathways.

Main Results:

• Nitrogen oxidation was observed, accompanied by significant catalyst surface reconstruction.
• Tensile strain on the gold catalyst surface was found to enhance oxygen (O₂) adsorption and dissociation.
• Newly formed active oxygen atoms on the gold surface were identified as key active sites.

Conclusions:

• The study provides direct evidence for the oxygen dissociation mechanism on gold surfaces.
• Tensile strain is a critical factor in enhancing the oxidation performance of nanogold catalysts.
• These findings offer new strategies for designing superior gold catalysts for nitrogen oxidation and activation.