Preparation and characterization of mesoporous carbon-supported Pt nanocatalyst and its stability under strong acidic solutions

摘要

Pt/C catalyst was prepared by the formic acid reduction method (FARM) using mesoporous carbon supports with submicron-scale particle size, which was synthesized by the nano-replication technique using mesoporous silica (MSU-H) as templates. The average size of the Pt particles, calculated from the Pt(111) peak by Scherrer equation, was found to be 3.3 nm. The chemical stabilities of PUC catalysts and polymer-coated Pt/C catalysts were examined in distilled water and in strong acidic solutions such as H2SO4 and HCIO4. The release amount of Pt in distilled water was found to be at trace levels (<3 ppb), which is close to the detection limits of ICP-AES. However, the Pt release greatly increased with time in both H2SO4 and HCIO4 solutions and reached a few percent levels in a week. On the other hand, a PVP/PEI-coated Pt/C catalyst showed much better stability that the Pt release was about 0.5% in 3 M HCIO4 for a week, compared with that of a pristine Pt/C catalyst.