Covalent and Strong Metal-Support Interactions for Robust Single-Atom Catalysts

Area of Science:

• Catalysis
• Materials Science
• Surface Chemistry

Background:

• Single-atom catalysts (SACs) offer optimal metal utilization and precise active sites but suffer from instability due to atom aggregation.
• Thermal stability of SACs is a critical challenge for both fundamental research and industrial applications.
• Metal-support interactions (MSIs) are known to influence the stability and performance of supported catalysts.

Purpose of the Study:

• To provide an overview of covalent MSIs (CMSIs) and classical strong MSIs (SMSIs) in the context of SACs.
• To summarize the applications of these MSIs in developing highly active and thermally stable SACs.
• To highlight the potential of MSIs for overcoming the stability limitations of SACs.

Main Methods:

• Investigated the role of MSIs, specifically CMSI and SMSI, in stabilizing single atoms on catalyst supports.
• Explored the concept of CMSI as covalent bonding between single metal atoms and support surface atoms.
• Demonstrated the identification and impact of SMSI in SACs, such as Pt1/TiO2.

Main Results:

• CMSI provides robust stabilization for single atoms through covalent orbital interactions with support lattice atoms, enabling higher metal loading.
• CMSI can be induced on various supports via doping and modulated by water treatment to balance stability and reactivity.
• SMSI was identified in SACs at higher reduction temperatures, enhancing stability and enabling selective encapsulation of metal nanoparticles while exposing single atoms.

Conclusions:

• MSIs, including CMSI and SMSI, are vital for enhancing the stability, activity, and selectivity of SACs.
• These interactions offer pathways for designing scalable, robust, and high-performance SACs for diverse applications.
• Further research into CMSI and SMSI holds promise for advancing the commercialization of SAC technology.