Fabricação e estudo catalítico de nanocatalisadores bimetálicos e monometálicos derivados de Pt e Pd ancorados em suportes mesoporosos modificados para redução de compostos poliaromáticos

Abstract

Monometallic Pt and Pd, and bimetallic PtPd nanoparticles supported on a mesoporous magnetic magnetite@silica matrix resembling a core-shell structure have been fabricated (Fe3O4@mSiO2). The material was characterized by transmission electron microscope (TEM), high angle anular dark field-scanning transmission electron microscopy (HAADF-STEM), X-ray photoelectron spectra (XPS), energy dispersive spectroscopy (EDS), inductively coupled plasma mass spectrometry (ICP-MS). The catalysts were applied in the hydrogenation of polyaromatic compounds, It was found that Anthracene as a model compound could be completely converted into the partially hydrogenated species by the monometallic and bimetallic solids. However, during the recycling study the bimetallic material (Fe3O4@mSiO2PtPd) showed an enhanced activity compared with the monometallic materials, and a single portion of the PtPd based catalyst was able to be used up to 10 times in the hydrogenation of Anthracene under mild conditions (6 atm of H2, 75 °C, 20 min). Thanks to the presence of magnetic core all three solids were capable of responding to an applied external magnetic field and once the reaction was completed, catalyst/product separation was not an issue as it is for several catalytic systems.