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Comparative Study of Cu-SSZ-13 and V 2 O 5 –WO 3 /TiO 2 Catalysts on Ammonia Storage and Slip Behavior

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide This study compared the adsorption–desorption behavior of NH 3 on Cu-SSZ-13 and V 2 O 5 –WO 3 /TiO 2 catalysts using an NH 3 –SCR flow reactor, systematically investigating the effects of temperature, space velocity, and NH 3 /NOx ratio on the ammonia storage performance and ammonia slip characteristics of catalysts. The relationship between ammonia storage capacity and NOx conversion efficiency as well as N 2 O formation was further analyzed. The results indicate that increasing temperature and space velocity reduce the ammonia storage capacity of the catalysts. Under conditions of high temperature (500 °C) and high space velocity (60,000 h –1 ), the saturated ammonia storage capacity of the catalyst decreases by 20–30%, leading to an increased risk of ammonia slip and causing ammonia slip to occur approximately 20% earlier during the NH 3 –SCR process. Excessive NH 3 /NOx ratios also exacerbate ammonia slip due to NH 3 overloading. In terms of reaction performance, higher ammonia storage capacity provides more active ammonia species on the catalyst surface, significantly enhancing the reduction activity. Particularly at temperatures below 300 °C, increased ammonia storage improves the NOx conversion efficiency of the catalyst. However, when the temperature exceeds 300 °C, due to the already high catalytic activity, the effect of ammonia storage on NOx conversion is not significant. It should be noted that excessive NH 3 adsorption not only improves NOx conversion efficiency but also leads to the formation of 15 ppm of the byproduct N 2 O, leading to secondary emission issues. Overall, Cu-SSZ-13 demonstrates superior ammonia storage capacity and reaction stability compared to the vanadium-based catalyst over a wide range of temperatures and space velocities. Its ammonia storage capacity is less affected by operational variations, thereby more effectively delaying ammonia slip.

Source: ACS Omega

DOI: 10.1021/acsomega.5c09913

Authors: Songfeng Li, Jiaran Li, Jinyuan Xu

Institutions: Jiangsu University of Science and Technology, State Grid Nanjing Power Supply Company (China), Chang'an University

Language: English

Topic: Catalytic Processes in Materials Science

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $1,935