Encapsulation of Pt nanoparticles into IPC-2 and IPC-4 zeolites using the ADOR approach

Zeolites with encapsulated metal nanoparticles (NPs) attract much attention due to the catalytic activity, stability and shape-selective properties of such materials in heterogeneous catalysis. One of the methods for introduction of metal NPs into the zeolite system is based on use of two dimensional (2D) layered precursors that are loaded with Pt source and consecutively transformed to three dimensional (3D) zeolites. This method can be combined with recently developed approach for zeolite synthesis; the ADOR (Assembly, Disassembly, Organization, and Reassembly) approach that is based on the 3D-2D-3D transformation of zeolites. Here, we report a synthesis of two ADOR zeolites: IPC-2 (OKO topology) and IPC-4 (PCR topology) functionalized with Pt NPs, Pt@IPC-2 and Pt@IPC-4, respectively. Pt@IPC-2 was prepared by intercalation of platinum(0)-2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetra siloxane into IPC-1P layered precursor and subsequent calcination. Pt@IPC-4 zeolite was prepared by the swelling of IPC-1P with the mixture of surfactant and Pt source. Final materials were investigated by XRD, nitrogen sorption, ICP-OES, and electron microscopy (SEM and STEM). Structural and textural analysis confirmed the successful syntheses of two ADOR zeolites. The size and distribution of Pt NPs were investigated by STEM. The platinum content was 0.34 wt% and 0.32 wt% and the average size of Pt NPs of 0.98 nm and 0.96 nm for Pt@IPC-2 and Pt@IPC-4, respectively. Pt@IPC-2 exhibited a broader range of Pt sizes due to larger pores.