Recently, various promoters for commercial selective catalytic reduction (SCR) catalysts are used to improve DeNOx activity at low temperature. We aimed at finding the optimum condition to prepare V2O5/TiO2 catalyst by changing promoters (W, Ce, Zr and Mn), not only for improving SCR reactivity, but also for reducing N2O formation at high temperature. In addition, we changed the order of impregnation between promoter and vanadium precursors on TiO2 support and observed its effect on activity and N2O selectivity. We utilized various analytical techniques, such as N2 adsorption-desorption, X-ray Diffraction (XRD), Raman spectroscopy, UV-visible Diffuse Reflectance Spectroscopy (UV-vis DRS) and Temperature Programmed Reduction with hydrogen (H2-TPR) to investigate the physicochemical properties of V2O5/TiO2 catalysts. It was found that W and Ce added V2O5/TiO2 catalysts showed the most active DeNOx properties at low temperature. Additionally, the difference in impregnation order affected the SCR activity. The superiority of low temperature activity of the vanadium firstly added catalysts (W or Ce/V/TiO2) is attributed to the formation of more polymerized V2O5 on the sample.
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http://dx.doi.org/10.1166/jnn.2016.11017 | DOI Listing |
Environ Sci Technol
September 2024
State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Regulating vanadia-based oxides has been widely utilized for fabricating effective difunctional catalysts for the simultaneous elimination of NO and chlorobenzene (CB). However, the notorious accumulation of polychlorinated species and excessively strong NH adsorption on the catalysts lead to the deterioration of multipollutant control (MPC) activity. Herein, protonated sulfate (-HSO) supported on vanadium-titanium catalysts via a preoccupied anchoring strategy are designed to prevent polychlorinated species and alleviate NH adsorption for the multipollutant control.
View Article and Find Full Text PDFEnviron Sci Technol
March 2022
State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China.
The VO/TiO (VTi) catalyst has been widely employed for the NH selective catalytic reduction (NH-SCR) reaction, and sulfur (S) and alkali metals (K) were usually considered as poisons during this reaction. In this work, the synergistic effect of S and K over the VTi catalyst for the NH-SCR reaction was analyzed and discussed. It is surprisingly observed that the synergistic effects of S and K exhibited a detoxification effect on the NH-SCR reaction.
View Article and Find Full Text PDFEnviron Sci Technol
March 2022
State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Selective catalytic reduction of NO by ammonia (NH-SCR) on VO/TiO catalysts is a widely used commercial technology in power plants and diesel vehicles due to its high elimination efficiency for NO removal. However, the mechanistic aspects of the NH-SCR reaction, especially the active sites on the VO/TiO catalysts, are still a puzzle. Herein, using combined operando spectroscopy and density functional theory calculations, we found that the reactivity of the Lewis acid site was significantly overestimated due to its conversion to the Brønsted acid site.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
August 2020
Shanxi Provincial Key Laboratory Higee-Oriented Chemical Engineering, North University of China, Taiyuan, 030051, Shanxi, China.
The deposition of NHHSO on catalysts is one of the key issues for selective catalytic reduction of NO. In this study, NHHSO was preloaded on catalysts, and the effects of MoO and CeO doping on the decomposition and reactivity of NHHSO on VO/TiO catalysts are studied. The results show that the introduction of MoO and CeO significantly promoted NO conversion on the VO/TiO catalysts.
View Article and Find Full Text PDFDalton Trans
March 2019
Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisboa, Universidade de Lisboa, Portugal.
Intensification of chemical processes according to the motto "faster, simpler, greener" is among the main concerns nowadays. One of the ways of intensification is the application of synergistic catalytic effects when the overall efficiency of a composite catalyst is much higher than the sum of the component activities. Here, we report on the preparation of synergistic catalytic materials by a simple and straightforward ball milling procedure.
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