Abstract
Ce modified MnOx-based catalysts have attracted much attention due to its high activity for selective catalytic reduction of NOx by NH3 (NH3-SCR) at low-temperatures. However, the most important role of Ce on the NH3-SCR performance of MnOx-based catalysts has not been confirmed. Herein, the typical Ce-Mn/TiO2 catalyst was synthesized through incipient-wetness impregnation method, the positive role of Ce on Ce-Mn/TiO2 catalyst in the NH3-SCR process was revealed by combining different activity tests (including NO oxidation and NH3 oxidation) and characterizations (including XRD, XPS and He-TPDMS experiments). It was found that the introduction of Ce can promote the dispersion of MnOx on TiO2 support. Meanwhile, the doping of Ce in MnOx can also increase the content of Mn4+ species. The Mn4+ species plays a crucial role in NO oxidation reaction, which can trigger the “Fast SCR” reaction and promote the conversion of NOx. This work provides insight into the catalyst design for NH3-SCR process at low-temperature.
Highlights
Nitrogen oxide (NOx), as one of the primary atmospheric pollutants, has attracted much attention for its harm on humans and the environment
NH3 began to be oxidized to NOx at 230 °C over Mn atom increases from 2.79% (Mn/TiO2) and Ce-Mn/TiO2 samples, which can explain the NH3-SCR deNOx activity start to decrease since 230 °C
The role of Ce over Ce-Mn/TiO2 catalyst can be assigned to two aspects: First, the introduction of Ce can promote the dispersion of MnOx on TiO2 support; Second, the dope of Ce in MnOx can increase the content of Mn4+, which possesses higher NO oxidation activity
Summary
Nitrogen oxide (NOx), as one of the primary atmospheric pollutants, has attracted much attention for its harm on humans and the environment. Selective catalytic reduction of NOx by NH3 (NH3-SCR) has been considered to be one of the most effective deNOx technology, and the core of this process lies in the catalyst [1]. The traditional NH3-SCR catalyst used in the power plant is composed of V2O5-WO3/TiO2, and its suitable working temperature is between 300 °C and 400 °C [2]. Developing low-temperature NH3-SCR catalyst (< 200 °C) is significance. MnOx-based catalysts have been widely investigated for their excellent NH3-SCR activity at low-temperature, especially after the modification of Ce element [4,5,6]. Combined with different activity tests (including NO oxidation and NH3 oxidation) and characterizations (including XRD, XPS and He-TPD-MS experiments) data, the positive role of Ce element on CeMn/TiO2 catalyst in the NH3-SCR process was revealed
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
