Sn-embedded graphene: An active catalyst for CO oxidation to CO2?

As is well known, looking for an appropriate catalyst which can oxidize the toxic CO molecule is of great importance. In this work, the favorable oxidation reaction of CO by molecular O-2 on Sn-embedded graphene (Sn-graphene) is investigated by using density functional theory calculations. Comparatively, both Eley-Rideal (ER) and Langmuir-Hinshelwood (LH) mechanisms of CO oxidation on Sn-graphene are studied. The CO oxidation reaction over Sn-graphene proceeds through the following steps: CO + O-2 -> OOCO -> O-ads + CO2 following by O-ads + CO -> OCO -> CO2. which passing via LH and ER mechanism, respectively. The barrier energies of these two steps are 0.41 and 0.11 eV. respectively, which are lower than those on the traditional noble metals. Our results reveal that the low-cost Sn-graphene can be used as an efficient catalyst for CO oxidation at room temperature. (C) 2015 Elsevier B.V. All rights reserved.