Exploring Reaction Mechanisms for the Reduction of NO Molecules over Al-or Si-Anchored Graphene Oxide: A Metal-Free Approach

摘要

Using periodic density functional theory calculations, the catalytic reduction of NO molecules is studied over a Al-or Sianchored graphene oxide (GO). It is found that the epoxy groups over GO could trap the Al or Si atom with a large adsorption energy and high diffusion barrier. Both “direct dissociation” and “dimer” mechanisms are studied for the reduction of NO molecules to N2O over these surfaces. According to our results, the NO reduction over Al or Si anchored GO proceeds through a dimer mechanism, due to its low activation energy. Moreover, the dimer mechanism should be more favorable than the direct dissociation since the adsorption energy of the (NO)2 dimer is found to be larger than that of a single NO monomer. Besides, the Si-anchored GO exhibits higher catalytic activity than the Al-anchored one. We hope that results of present study provide a valuable guidance on design graphene-based single-atom catalysts to remove toxic NO molecules.