Detailed mechanism of the NO plus CO reaction on Rh(100) and Rh(111): A first-principles study

作者：Tan, Lu; Huang, Liangliang; Liu, Yingchun^*; Wang, Qi^*

来源：Applied Surface Science, 2018, 444: 276-286.

DOI：10.1016/j.apsusc.2018.03.059

• Nitrogen oxides
• Carbon monoxide
• Rhodium
• Density functional theory
• Reaction mechanism
• Catalysis

Through DFT calculations, the detailed mechanism of the catalytic NO + CO reaction, a prototypical system with great practical applications especially in the automobile-exhaust aftertreatment, was determined on Rh(100) and Rh(111). The elementary steps and their energy evolution were revealed. These steps include NO dissociation, N-2 formation through N recombination, CO2 formation, and N2O formation, transformation, and dissociation. The reaction steps of NO2 formation and direct reaction between NO and CO were also studied, and were verified to be relatively insignificant in this reaction system. Results shed light on the atomic-level origin why Rh(100) is more active for this reaction system and more selective for the production of N-2 versus N2O compared with Rh(111). Meanwhile, the preference between the two routes for N-2 production, i.e., N atoms recombination and N2O as intermediate, was found to be dependent on the distribution of surface species and the interaction among them intricately. This work provides a basis for further kinetic modeling to investigate the catalytic properties on a realistic scale.

• 出版日期2018-6-30
• 单位浙江大学