Sequestration and selective oxidation of carbon monoxide on graphene edges

The versatility of carbon nanostructures makes them attractive as possible catalytic materials, as they can be synthesized in various shapes and chemically modified by doping, functionalization, and the creation of defects in the nanostructure. Recent research has shown how the properties of carbon nanostructures can be exploited to enhance the yield of chemical reactions such as the thermal decomposition of water (Kostov et al 2005 Phys. Rev. Lett. 95) and the dissociation of methane into carbon and hydrogen (Huang et al 2008 J. Chem. Phys. at press). In this work, we consider the carbon-mediated partial sequestration and selective oxidation of carbon monoxide (CO), both in the presence and absence of hydrogen. Using first-principles calculations we study several reactions of CO with carbon nanostructures, where the active sites can be regenerated by the deposition of carbon decomposed from the reactant (CO) to make the reactions self-sustained. Using statistical mechanics, we also study the conditions under which the conversion of CO to graphene and carbon dioxide is thermodynamically favorable, both in the presence and in the absence of hydrogen. These results are a first step toward the development of processes for the carbon-mediated partial sequestration and selective oxidation of CO in a hydrogen atmosphere.