Towards Encapsulation of Nanoparticles in Chabazite Through Interzeolite Transformation

Abstract

Abstract Encapsulation of Pt nanoparticles (1–2 nm) in the small pore zeolite chabazite (CHA) was achieved by a seed‐ and structure‐directing agent‐free interzeolite transformation from zeolite Y (FAU). Prior to the transformation, the Pt nanoparticles were encapsulated in the commercially available large pore zeolite H−Y by simple incipient wetness impregnation. The H−Y was then converted into CHA in a solution of KOH under hydrothermal conditions at 95 °C. All catalysts were characterized by XRD, N 2 ‐physisorption, H 2 ‐chemisorption, TEM and XPS and their catalytic activity were tested in CO oxidation. Although the catalytic activity of the encapsulated Pt nanoparticles decreased over time, it still remained more active than a reference catalyst prepared by impregnation. The thermal stability of the catalysts was investigated after calcination at 400 °C for 18 hours. Compared to the other catalysts, the encapsulated Pt nanoparticles only resulted in a small decrease in catalytic activity.