Authors: J.A. Huertas-Miranda, M.M. Martínez-Iñesta
Affilation: University of Puerto Rico, United States
Pages: 633 - 636
Keywords: molecular simulation, zeolites, nanowires, platinum
Previous molecular simulation studies in our group using Metropolis Monte Carlo (MMC) technique suggested that lower Si to Al ratios (Si/Al) favored energetically the positioning of Ni atoms inside the one-dimensional main pore channels of zeolites with CAN- and MOR-type frameworks. We report here molecular simulation results in MOR- and VET-type zeolites for the formation of Pt nanostructures. These two zeolites have 1-D channel frameworks that would promote the formation of nanowires. Because of its effect in the kinetic energy of molecules, it is expected that temperature affects the final positioning of guest metal atoms in the zeolite frameworks. We have studied the combined effect of temperature and the Si/Al on the positioning of Pt metal atoms inside MOR- and VET- type zeolites at different Pt loadings. Our results suggest that high temperatures promote the diffusion of Pt atoms outside the main pore channels in the MOR framework. It is also observed that at high Pt concentrations, one dimensional Pt structures are formed in the main pore channels of MOR and VET. Out results suggest that there are optimum structure, loading and temperature combinations that promote the formation of metal nanowires.
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