Details

Autor(en) / Beteiligte

• Jin, Jiamin
• Chen, Jianfu
• Wang, Haifeng
• Hu, Peijun

Titel

Insight into room-temperature catalytic oxidation of NO by CrO2(110): A DFT study

Ist Teil von

• Chinese chemical letters, 2019-03, Vol.30 (3), p.618-623

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2019

Quelle

Elsevier ScienceDirect Journals

Beschreibungen/Notizen

• The first-principles DFT calculations together with microkinetic analysis reveal the complex catalytic mechanism of low-content NO oxidation on CrO2(110) at room temperature. It quantitatively makes clear that CrO2(110) can exhibit considerable activity with the Mars-van-Krevelen mechanism preferred, and the nitrate species serves as the key poisoning species. [Display omitted] The NO oxidation processes on CrO2(110) was investigated by virtue of DFT + U calculation together with microkinetic analysis, aiming to uncover the reaction mechanism and activity-limiting factors for CrO2 catalyst. It was found that NO oxidation on CrO2(110) has to be triggered with the lattice Obri involved (Mars-van Krevelen mechanism) rather than the Langmuir-Hinshelwood path occurring at the Cr5c sites alone. Specifically, the optimal reaction path was identified. Quantitatively, the microkinetic analysis showed that CrO2(110) can exhibit a high turnover rate of 0.978 s-1 for NO oxidation at room temperature. Such an activity could originate from the bifunctional synergetic catalytic mechanism, in which the Cr5c sites can exclusively adsorb NO and the Obri is very reactive and provides oxidative species. However, it is worth noting that, as the reactive Obri tightly binds NO2, the nitrate species was found to be difficult removed and constituted the key poisoning species, eventually limiting the overall activity of CrO2. This work demonstrated the considerable catalytic ability of CrO2 for NO oxidation at room temperature, and the understanding may facilitate the further design of more active Cr-based catalyst.