Synthesis and characterization of Pt, Au or Pd clusters deposited titania-modified mesoporous silicate MCM-41

摘要

Nanosized metal clusters Pt, Au and Pd were deposited in the mesopore of titania-modified MCM-41 by the photocatalytic reduction method under the mild conditions. The resulting Pt-, Au- or Pd-deposited titania-modified MCM-41 were characterized by using XRD, nitrogen adsorption―desorption isotherms, X-ray photoelectron spectroscopy (XPS), TEM and diffuse reflectance UV―Vis spectroscopy. The results showed that Pt(Ⅳ), Au(Ⅲ) or Pd(Ⅱ) was reduced to metallic Pt, Au or Pd efficiently on the surface of titania, which modified over the inner surface of mesopore of the MCM-41 after the UV light irradiation for 4h, and the metal nanoparticles deposited in the channels of the titania-modified MCM-41. The BET surface areas and pore volumes of the metal deposited samples decreased due to the noble metal clusters in the mesopore. The UV absorption spectra of titania-modified MCM-41 broadened and changed the UV absorption in the range of 190―300 nm after loading the metal clusters.