| Platinum on carbon is one of the most common catalysts, having a wide range of applications. The performance of the catalysts can be enhanced by well-dispersed, stable platinum nanoparticles. One of the causes for the loss of catalytic activity is the growth, or sintering, of the nanoparticles. We suggest that the structural stability of nanometer-sized platinum catalyst particles can be enhanced by increasing the interaction of the nanoparticles with the carbon support, relative to the Pt-Pt interactions, which can prolong the activity of the catalysts. In an effort to increase the interaction between the metal and the support, carbon substituted boron defects were introduced in carbon, and the adsorption energies of the metal atoms and clusters (Pt, Ru, and Au) were estimated to be substantially higher (as high as 40 kcal/mol) when compared to pristine carbon using first-principles density functional theory (DFT) calculations.;The dynamics of the metal atoms and clusters were studied at elevated temperatures on the pristine and boron doped carbon using ab initio molecular dynamics simulations. The mobility of the metal atoms on the boron-doped carbon was estimated to be lower than on pristine carbon even at temperatures of 673 K. The activity of the catalysts was also estimated for the CO oxidation reaction using DFT calculations. The adsorption energies of the gases, and the activation barrier for the reaction were calculated, which showed a moderate support-induced effect when the Pt is only a few layers thick.;To support the simulation results with experiments, boron doped amorphous carbon powders were produced at 1000°C and under 1 atmosphere of pressure using a simple tube furnace apparatus. Characterization of the carbon samples using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Raman has shown the presence of boron in the carbon lattice. Platinum nanoparticles were deposited on the pure and boron-doped carbon support by surfactant templating method. The stability and activity of the nanoparticles were tested with XPS and cyclic voltammetry (CV) experiments. The experimental results were in reasonable agreement with the simulation predictions. |
