Self-assembly film of zeolite Y nanocrystals loading palladium on an Au electrode for electrochemical applications

Nano-scale zeolite Y crystals were synthesized, and palladium nanoparticles were prepared in the supercage of the zeolite by "ship-in-a-bottle" approach. A novel method to fabricate zeolite-modified electrode (ZME) loading Pd nanoparticles was developed, in which the zeolite Y loading Pd2+ ions was self-assembled on (3-mercaptopropyl) trimethoxysilane-attached An surface to form the stable and density packed multilayers (SAM-ZME). The structures of zeolite Y and the SAM-ZME were investigated by using TEM, XRD and SEM techniques. Pd2+ ions in the SAM-ZME were converted into Pd nanoparticles (Pd-n(0)) by two steps consisting of the electrochemical reduction as well as the succeeding admission and release of CO. The redox couple [Fe(CN)(6)](3-/4-) was used to probe the electron-transfer barrier properties during self-assembling process. Moreover, the special properties of the SAM-ZME loading Pd-n(0) were studied by using cyclic voltammetry and CO-probe in situ FTIR spectroscopy. The results illustrated that Pd-n(0) in the SAM-ZME exhibits higher electrocatalytic activity for oxidation of adsorbed CO than that of ZME prepared in our previous study by zeolite coating method. The present study is of importance in design and preparation of SAM-ZME, which poccesseses excellent properties for the immobilization of electrocatalysts or biomolecules