DFT Study on the C-NO Coupling Reaction with Different Active Sites

The heterogeneous interaction between NO and char with two to four active sites (R1-R3) has been studied using density functional theory (DFT). The thermodynamic parameters which can be used as an important foundation for distinguishing the differences in reaction mechanism are calculated. The calculations show that active sites play an important role in NO adsorption. R3 provides more sites for NO adsorption, which is more favorable for NO chemisorption. The energy barrier for NO reduction to N2O or N-2 on R1, R2, and R3 surface is 122.25, 81.5, and 38.4 kJ/mol, respectively, signifying that the more active sites on char surface are more conducive to NO reduction. On the other hand, the difference in energy barrier values of N-2 desorption on R2 and R3 surface reveal that oxygen-containing groups on different char surface have different effects on N-2 desorption. Thermodynamic parameters of char-NO reaction at different active sites are further analyzed, and the strong dependence of the reaction process on the active sites is clarified through thermodynamics. The calculation results deepen the mechanism of NO reduction and lay a foundation for further research.

Automated summary

The study used density functional theory to analyze the heterogeneous interaction between NO and char, revealing the important role of active sites in NO adsorption and reduction. Thermodynamic parameters demonstrated the impact of different active sites on the reaction mechanism, confirming the significance of active sites in the process of NO reduction.