Sequestration and selective oxidation of carbon monoxide on graphene edges

Abstract

The versatility of carbon nanostructures makes them attractive as possible catalyticmaterials, as they can be synthesized in various shapes and chemically modified by doping,functionalization, and the creation of defects in the nanostructure. Recent research hasshown how the properties of carbon nanostructures can be exploited to enhance the yield ofchemical 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 2008J. Chem. Phys. at press). In this work, we consider the carbon-mediated partialsequestration and selective oxidation of carbon monoxide (CO), both in the presence andabsence of hydrogen. Using first-principles calculations we study several reactions of COwith carbon nanostructures, where the active sites can be regenerated by thedeposition of carbon decomposed from the reactant (CO) to make the reactionsself-sustained. Using statistical mechanics, we also study the conditions underwhich the conversion of CO to graphene and carbon dioxide is thermodynamicallyfavorable, both in the presence and in the absence of hydrogen. These resultsare a first step toward the development of processes for the carbon-mediatedpartial sequestration and selective oxidation of CO in a hydrogen atmosphere.