Bimetallic sites supported on N-doped graphene ((Fe,Co)/N-GN) as a new catalyst for NO oxidation: A theoretical investigation

Nitric oxide (NO) releasing from power plants has caused global concerns. Converting NO to NO2 by catalytic oxidation technology is a promising method for NO elimination. Adsorption characteristics of corresponding gases and mechanism of NO oxidation on the surface of (Fe,Co)/N-GN catalyst were systematically investigated via density functional theory calculation. The detailed reaction paths in mechanism of Eley-Rideal and Langmuir-Hinshelwood were studied respectively and the thermodynamic and kinetic analysis of each path were performed to further understand the impact of temperature on the chemical equilibrium constant and reaction rate constant. It was observed that NO can be easily oxidized to NO2 on the surface of (Fe,Co)/N-GN with the smallest energy barriers about 0.17 eV in E-R mechanism, but the oxidation of NO in boiler is more likely to take place in L-H mechanism due to lower desorption barrier of generated NO2. Besides, we found CO played a promoting role in removal of residual oxygen atom, and H2O and SO2 had little impact on reaction under 800 K. We hope this work can not only lay a foundation for theoretical study of NO oxidation, but also provide a guideline for NO elimination in the coal-fired power plants.