DFT study on the reaction mechanism of N2O reduction with CO catalyzed by char

Abstract The effect of char during the heterogeneous reduction of N 2 O by CO has been studied using density functional theory (DFT). The armchair and zigzag configurations with six and seven aromatic ring clusters are selected as the carbonaceous surfaces. The calculation results show that heterogeneous reduction of N 2 O by CO on char surface undergoes two stages: N 2 O reduction and residual oxygen desorption. Char has a significant catalytic effect on the reduction of N 2 O by CO, which not only provides reactive sites for CO and N 2 O but also significantly reduces the activation energy of N 2 O reduction. On the one hand, the presence of CO significantly reduces the activation energy of N 2 desorption on the char surface, and synergize with char to promote N 2 O reduction. On the other hand, it significantly reduces the activation energy of CO 2 desorption and is beneficial to CO 2 release. Char edge types have different catalytic effects on N 2 O heterogeneous reduction, and zigzag char is more advantageous in kinetics than armchair char. This study makes contributions to enrich the mechanisms of N 2 O reduction during combustion.