Reactant-Induced Structural Evolution of Pt Catalysts Confined in Zeolite

Area of Science:

• Heterogeneous catalysis
• Materials science
• Nanotechnology

Background:

• Reactant-induced structural changes in heterogeneous metal catalysts often lead to active site formation or deactivation.
• Controlling the size and stability of metal nanoparticles within supports is crucial for catalytic performance.

Purpose of the Study:

• To investigate the structural transformation of subnanometer platinum (Pt) clusters within a pure-silica MFI zeolite.
• To correlate structural evolution under various reactant atmospheres (CO, O2, H2O) with catalytic activity for CO oxidation.
• To assess the impact of iron (Fe) incorporation into the zeolite framework on Pt species stability.

Main Methods:

• Synthesis of Pt-zeolite materials with controlled Pt species size (single atoms to nanoparticles).
• Treatment of materials under specific reactant atmospheres (CO, O2, H2O).
• Characterization of structural evolution and catalytic testing for CO oxidation.
• Incorporation of Fe into the zeolite framework for stability studies.

Main Results:

• Precise modulation of Pt species size distribution (single atoms to 1-5 nm nanoparticles) achieved through reactant atmosphere pretreatment.
• Development of highly active and stable Pt species for CO oxidation.
• Fe incorporation significantly enhanced the stability of Pt species against sintering at high temperatures (up to 650 °C).

Conclusions:

• Reactant-induced structural evolution is a key factor in controlling Pt cluster size and catalytic performance in zeolites.
• Fe-promoted Pt-zeolite materials exhibit superior stability under harsh conditions, making them promising for catalytic applications.