In situ preparation of platinum nanoparticles in mesoporous silica using linear polyethyleneimine as a protective agent

Ordered mesoporous silica SBA-15 with homogeneously dispersed platinum nanoparticles ( PtNPs) was prepared via a sol-gel process. The PtNP content in the SBA-15 support as a result of this procedure was estimated to be up to 0.029 wt% using inductively coupled plasma analysis. Small-angle X-ray scattering measurements revealed that SBA-15 with PtNPs possessed regular pores with a two-dimensional hexagonal structure and p6mm symmetry. Nitrogen adsorption/desorption measurements for SBA-15 revealed an average pore size of 5.8nm and a Brunauer-Emmett-Teller surface area as high as 1034 m(2)/g; this pore size is comparable to those of SBA-15 prepared using the conventional immersion method while the specific surface area is higher. Transmission electron microscopy with energy dispersive X-ray spectrometry revealed that the PtNPs were dispersed in the as-prepared SBA-15 interpore. These results indicate that this method is a new route for preparing SBA-15 with PtNPs that suppresses aggregation between the PtNPs. (C) 2019 The Ceramic Society of Japan. All rights reserved.