DFT Study of the Catalytic Mechanisms of NO Heterogeneous Reduction: The Effect of the Gasification Reaction

ABSTRACT

The NO heterogeneous reduction mechanisms on both Ca-char and gasified Ca-char by b3lyp/6–311+g (d, p) group are systematically investigated to clarify the role of the catalyst. All the computed reaction paths can proceed smoothly after the first step occurs, and they are exothermic during the reaction process, which means this reaction is supported by thermodynamics and kinetics. The results indicated that Ca can promote NO heterogeneous reduction by increasing the adsorption energy and reducing the energy barrier of gas products (nitrous oxide N₂O, nitrogen N₂, CO and CO₂) emission. Furthermore, the computed results also indicated that the model is a significant element affecting NO reduction. Compared with Ca-char model, gasified Ca-char model has higher potential energy surface and tends to remain O atoms. The computed reaction path on the surface of gasified Ca-char is a supplement to previous studies, which gives insight to the catalytic mechanisms of NO heterogeneous reduction in the presence of gasification.

KEYWORDS:

• Ca
• DFT
• char
• gasification
• nO heterogeneous reduction

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work is financially supported by the National Natural Science Foundation of China (No. 52276127) and Natural Science Foundation of Shanghai (Grant No. 21ZR1434300).