(39e) Methanol Oxidation on Platinum Nanoparticles Supported on Well Defined Mesoporous Carbons

A mesoporous carbon structure was template-synthesized from small nanoparticles of silica with internal M41S type mesopores. The silica template was synthesized according to Suzuki et al. using an ionic surfactant to create the internal mesopores 1.8 ? 3.5 nm diameter and a non-ionic surfactant to limit the overall size of the particle. Larger mesopores in the silica are needed for carbonization to a better structure. This was achieved by the use of a swelling-agent, tri-methylbenzene (TMB). Characterization by transmission electron microscopy (TEM), X-ray diffraction pattern (XRD) and nitrogen sorption analysis showed a meso-cellular foam like carbon structure composed of porous cells with internal hexagonally arranged channels. In addition to the 3 nm internal channels, there were larger mesopores connecting the cellular domains. These larger mesopores were formed in the inter-particle voids created during carbonization. The dual porosity network structure had a high surface area (> 1000m2/g) and large pore volume (> 1.2 mL/g). When loaded with Pt-Ru nanoparticles, the PtRu/carbon became a good electrocatalyst and gave higher activity for methanol oxidation compared to a commercial catalyst.