Tunable Interfacial Electronic Pd-Si Interaction Boosts Catalysis via Accelerating O₂ and H₂O Activation.

Area of Science:

• Heterogeneous catalysis
• Surface science
• Materials chemistry

Background:

• Engineering interfaces between noble metals and oxides is crucial for catalyst performance.
• Non-reducible oxides present unique challenges for catalyst design.
• Interfacial sites significantly influence metal electronic and d-band structures, impacting catalytic reactions.

Purpose of the Study:

• To create an active palladium-silica (Pd-Si) interface with tunable electronic metal-support interaction (EMSI).
• To enhance the performance of heterogeneous catalysts for formaldehyde oxidation.
• To investigate the role of interfacial structure in catalytic activity.

Main Methods:

• Growing a thin permeable silica layer on ZSM-5 to form Pd@SiO2/ZSM-5.
• Utilizing experimental results combined with density functional theory (DFT) calculations.
• Analyzing charge transfer and electronic structure modifications at the Pd-Si interface.

Main Results:

• The Pd-Si interface enhanced charge transfer from silicon to palladium, creating an electron-rich Pd surface.
• Lowered activation barriers for O2 and H2O, facilitating formaldehyde oxidation.
• Demonstrated that moderate EMSI promotes the Pd(0) ⇆ Pd(2+) catalytic cycle, improving reactant adsorption and activation.

Conclusions:

• The Pd-Si active interface significantly enhances formaldehyde oxidation.
• Tunable EMSI is a promising strategy for designing high-performance noble metal catalysts.
• This approach offers a new pathway for developing advanced heterogeneous catalysts for practical applications.