Insight into Interparticle Hydrogen Spillover Driven by Remote Metal Oxides

Area of Science:

• Heterogeneous catalysis
• Surface science
• Materials chemistry

Background:

• Hydrogen spillover involves H2 dissociation and hydrogen diffusion on solid supports.
• Intraparticle spillover is well-studied, but interparticle spillover remains less understood.
• Interparticle spillover at interfaces is crucial for unique catalytic performances.

Purpose of the Study:

• To systematically examine interparticle hydrogen spillover between different catalyst specimens.
• To investigate the role of various metal oxide supports in facilitating or hindering spillover.
• To provide insights for designing advanced catalyst supports.

Main Methods:

• H2-temperature-programmed reduction (H2-TPR) to assess reduction temperatures.
• In situ X-ray absorption fine structure (XAFS) for structural analysis.
• Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy for surface species identification.

Main Results:

• Ni2+/TiO2 and Ni2+/WO3 showed decreased reduction temperatures when combined with Pt, indicating successful interparticle spillover.
• Ni2+/CeO2 did not exhibit reduced reduction temperatures, suggesting it's an ineffective hydrogen acceptor in this context.
• Interparticle reverse hydrogen spillover facilitated benzene/n-heptane coupling with Al-mont and TiO2-supported Pd.

Conclusions:

• Interparticle hydrogen spillover is achievable with specific catalyst-support combinations (e.g., Pt/TiO2, Pt/WO3).
• The choice of hydrogen acceptor material (e.g., CeO2) significantly impacts spillover efficiency.
• This study provides valuable understanding and design principles for engineered catalysts utilizing interparticle spillover.