Work

Unraveling the Positive Role of WO3 on Supported Vanadium Catalysts for NOx Reduction by Operando Spectroscopy

Year: 2024

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Selective catalytic reduction of nitrogen oxides (NO x ) by ammonia (NH 3 –SCR) over supported vanadium catalysts is a commercial technology for NO x abatement in combustion exhaust. The addition of tungsten oxide (WO 3 ) significantly enhances the performance of supported vanadium catalysts (V 2 O 5 /TiO 2 ), but the mechanism underlying this enhancement remains controversial. In this study, we employed combined operando spectroscopy (DRIFTS-UV–vis-MS) to investigate the dynamic state of active sites (acid sites and redox sites) on V 2 O 5 –WO 3 /TiO 2 during the NH 3 –SCR reaction. Our findings confirmed that WO 3 occupied the TiO 2 surface and reduced the available surface sites for V 2 O 5 anchoring, thus promoting the agglomeration of vanadia species. This structural effect significantly improved the reducibility of VO x on V 2 O 5 –WO 3 /TiO 2 catalysts, consequently enhancing the efficiency for NO x reduction. The heightened reducibility rendered the reoxidation of vanadia species a rate-limiting step, resulting in the presence of vanadia species in a lower oxidation state (V 4+ ) during the NH 3 –SCR reaction.

Source: ACS Omega

DOI: 10.1021/acsomega.4c06372

Authors: Zhihui Lv, Guangyan Xu, Yingjie Wang, Yunbo Yu, Hong He

Institutions: Chinese Academy of Sciences, State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Institute of Urban Environment

Language: English

Topic: Catalytic Processes in Materials Science

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,935

Funders: National Natural Science Foundation of China, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, National Key Research and Development Program of China