Structural characterization of Au clusters deposited in the pores of the zeolite H-ZSM-5 using pulsed laser ablation in liquid

Abstract

Gold clusters were deposited in the pores of the zeolite H-ZSM-5 using pulsed laser ablation of an Au target placed in acetone containing the zeolite particles. The Au clusters in the pores of the zeolite were observed using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The images revealed that most pores in the zeolite contained Au clusters. Additionally, the position of each Au atom in the clusters was determined by analyzing the HAADF-STEM images. The results revealed that when three Au atoms were visible in a pore, they were planar and aligned mostly parallel to the viewing plane, and when more than three Au atoms were present, a three-dimensional structure was formed because of the steric hindrance of the pore wall. Therefore, the Au clusters were deposited in the zeolite pores. Furthermore, most clusters in the pores were distributed near the surface of the channels of the zeolite particles.