Strong Metal-Support Interactions between Gold Nanoparticles and Nonoxides

Area of Science:

• Catalysis
• Materials Science
• Nanotechnology

Background:

• Strong metal-support interaction (SMSI) is crucial for supported catalysts in heterogeneous catalysis.
• Classic SMSI typically occurs under reductive conditions with oxide supports.
• Gold nanoparticles (Au NPs) are widely used in catalysis but prone to sintering.

Purpose of the Study:

• To report the first instance of SMSI between Au NPs and hydroxyapatite (HAP), a non-oxide support.
• To investigate the characteristics and implications of this novel SMSI.
• To explore the potential for designing advanced supported gold catalysts.

Main Methods:

• Synthesis of Au nanoparticles supported on HAP.
• Characterization of the Au/HAP system using techniques like CO adsorption and electron microscopy.
• Evaluation of catalytic performance in liquid-phase reactions.
• Testing sintering resistance under calcination.

Main Results:

• Demonstrated reversible encapsulation of Au NPs by HAP, electron transfer, and altered CO adsorption, characteristic of SMSI.
• Observed SMSI under oxidative conditions, contrasting with classical SMSI.
• Enhanced sintering resistance of Au NPs after calcination.
• Improved selectivity and reusability of Au/HAP catalysts in liquid-phase reactions.
• Confirmed the generality of this SMSI with other phosphate supports like LaPO4.

Conclusions:

• Established a novel SMSI between Au NPs and HAP under oxidative conditions.
• The discovered SMSI significantly improves the stability and catalytic properties of supported gold.
• This finding offers a new strategy for developing robust and tunable supported gold catalysts.