An Extended Strong Metal-Support Interaction Effect: An Ultrathin Gold Wetting Layer on Molybdenum Nitride

Area of Science:

• Materials Science
• Surface Chemistry
• Nanotechnology

Background:

• The strong metal-support interaction (SMSI) effect is crucial in catalysis, typically studied in metal/oxide systems.
• Understanding metal/non-oxide interfaces, like metal/nitride, is essential for advancing materials science.
• The fundamental nature of interfacial interactions in non-oxide systems requires further investigation.

Purpose of the Study:

• To investigate and demonstrate an extended strong metal-support interaction (SMSI) regime in a metal/nitride system (Au/MoNx).
• To systematically explore the atomic structure, aggregation state, and electron transfer at the Au/MoNx interface under varied conditions.
• To expand the concept of SMSI beyond traditional metal/oxide supports.

Main Methods:

• Synthesis of Au/MoNx using a controllable vapor-liquid-solid method.
• Systematic investigation of atomic structure, aggregation, and electron transfer using advanced characterization techniques.
• Controlled manipulation of interfacial states via alternating high-temperature nitridation and oxidation treatments.

Main Results:

• Au species form a highly dispersed wetting-layer-like structure on MoNx under reductive nitridation, showing strong interfacial charge transfer.
• Oxidation treatment leads to Au nanoparticle aggregation and weakened electronic interactions.
• The two distinct interface states (wetting layer and aggregated nanoparticles) are reversibly interconverted by alternating nitridation and oxidation.

Conclusions:

• Demonstrated an extended SMSI effect in the metal/nitride (Au/MoNx) system, expanding the traditional metal/oxide paradigm.
• Established a reversible control over interfacial structure and electronic properties in metal/nitride systems.
• Highlights the potential of nitride supports for novel catalytic and electronic applications through tunable SMSI.