Details

Autor(en) / Beteiligte

• Xing, Jiaying
• Xue, Qitong
• Chen, Jianjun
• Mi, Jinxing
• Chen, Xiaoping
• Shi, Jianqiang
• Liu, Zhiming
• Li, Junhua

Titel

Potential Risk of Significant N 2 O Emission without Changing NO x Conversion on Commercial V 2 O 5 /TiO 2 Catalyst under Working Conditions

Ist Teil von

• Environmental science & technology, 2023-12, Vol.57 (51), p.21866-21875

Ort / Verlag

United States

Erscheinungsjahr

2023

Quelle

MEDLINE

Beschreibungen/Notizen

• Vanadium-based catalysts play a pivotal role in the emission control of industrial NO via selective catalytic reduction (SCR) technology. However, little attention has been paid to the potential emission of greenhouse gas N O under complex working conditions. This work reports that a commercial V O /TiO catalyst may lead to significant N O emission without greatly changing the outlet NO concentration after chromium (Cr) deposition. With a Cr loading of 2 wt %, N O concentration increased from 27.8 to 199.2 ppm at 350 °C with the value of outlet N O/(N O+N ) from 2.5% to 19.4%. Experimental results combined with DFT+U calculations suggest that nonselective catalytic reduction (NSCR) is the main route for N O formation in a wide temperature range of 250 ∼ 400 °C. It is stemmed from the fact that the covalent interaction between Cr and V species on the V O /TiO surface accelerates the conversion of V + Cr → V + Cr , leading to a larger proportion of surface V . More importantly, surface V is highly related to the redox property of the V O /TiO catalyst, which is beneficial to NSCR reaction rather than the standard SCR process. The work suggests that to better inhibit the emission of greenhouse gases during the NH -SCR process, monitoring N O emission should be included along with the NO concentrations, especially in complex flue gases.