Al-Embedded C2N: a DFT study on a promising catalyst for CO oxidation

Abstract

The development of high-efficiency and low-cost catalysts for CO oxidation is of great significance. Here, the catalytic oxidation of CO over an Al–C₂N surface was systematically investigated based on DFT calculations. There are three different reaction mechanisms for the oxidation of CO by O₂ molecules, including the traditional Langmuir–Hinshelwood (LH) mechanism, Eley–Rideal (ER) mechanism, and the trimolecular mechanism reported recently. The result reveals that the LH and trimolecular mechanisms are preferable for CO oxidation with the highest energy barriers of merely 3.4 and 3.0 kcal mol⁻¹, respectively, which are far smaller than the 40.2 kcal mol⁻¹ energy barrier of the ER mechanism. N₂O is considered a harmful air pollutant that destroys the ozone layer and has a certain oxidability. We have also studied the reaction mechanism of CO oxidation by N₂O. It is found that the highest energy barrier for the oxidation of CO by N₂O is only 6.5 kcal mol⁻¹. These results indicated that the Al–C₂N material can be used as a promising candidate catalyst for CO oxidation under mild conditions.