Synthesis and Characterization of Platinum-Containing Ordered Mesoporous Carbon with High Specific Surface Area

Abstract

A Pt-containing ordered mesoporous carbon with a high specific surface area was synthesized through evaporation-induced multi-constituent co-assembly method, wherein soluble resol polymer is used as the carbon precursor, silicate oligomers as the inorganic precursor, triblock copolymer as the template, and H2PtCl6•6H2O as the Pt precursor. After thermopolymerization, the template was removed by calcinations, and silica was removed by NaOH solutions. The resultant sample was characterized by X-ray diffraction, nitrogen sorption and transmission electron microscopy. The results showed that the carbon material exhibited highly ordered mesoporous structure, with a high specific surface area of 1560 m2/g, and the pore size distributions of the sample are very narrow, centering at around 6 nm; and the platinum particles with sizes of less than 8 nm were highly distributed in the carbon matrix. The high specific surface area may be ascribed to plenty of small pores inside carbon walls caused by the removal of silica from the composites. Interaction between the Pt4+ and the resin caused the Pt species to be incorporated into the framework of the resin, which was self-assembled into an ordering structure under the direction of the surfactant. After being subjected to pyrolysis at a high temperature, the Pt4+ ions were gradually reduced to form Pt nanoparticles, which were strongly imbedded in the carbon substrate and thereby thermally stable. The removal of silica may result in the exposure of Pt nanoparticles, which render Pt nanoparticles to contact easily with reactant molecules.