(403a) Characterization Of Boron-Doped Carbon Synthesized Under Atmospheric Conditions And Its Influence On Pt Nanoparticles

The activity of nanometer-sized catalyst particles may be prolonged by stabilizing the catalysts on various supports. The stability may possibly be increased by strengthening the interaction between the nanoparticles and the support, thus decreasing the mobility and the agglomeration of the catalyst particles. Our density functional theory calculations of Pt and PtRu clusters on carbon supports have shown that the adsorption energies of these metal clusters increased substantially in the presence of substitutional boron defects in carbon lattice. To corroborate the simulation results with experiments, boron doped amorphous carbon powders were produced at 1000C and under 1 atmosphere of pressure using a simple tube furnace apparatus. Doping of the powders was monitored using XRD and Raman spectroscopy, and doping was confirmed by XPS. The XPS data showed a peak at 188 eV which coincides with the B1s energy when bound to carbon. XRD data showed a decreasing d002-spacing between graphitic planes, indicating increased graphitization. The full width at half maximum of this peak also decreased, owing to a more ordered powder. Raman microscopy was performed on the samples and showed a decrease in the G-band, which is due to the substitution of boron into the graphitic lattice. The intensity ratio of the G- to D-Bands increased, indicating larger grain sizes in the powders. Platinum nanoparticles were deposited on pure and boron-doped carbon and the stability of the nanoparticles were tested using XRD and HRTEM. The activity of the catalysts for reactions such as CO oxidation was also analyzed.