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Wei N, Hu X, Zhao C, Tong Z, Yun J, Jiang X, Wang K, Zou Y, Chen Z. Unveiling alkali metal poisoning of CrMn catalyst for selective catalytic reduction of NO x with NH 3: An experimental and theoretical study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 873:162294. [PMID: 36801342 DOI: 10.1016/j.scitotenv.2023.162294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
Alkali metal poisoning has been an intricate and unsolved issue confining the catalytic activity of NH3-SCR catalysts up to now. Herein, the effect of NaCl and KCl on catalytic activity of CrMn catalyst for NH3-SCR of NOx was systematically investigated to clarify the alkali metal poisoning by combined experiments and theoretical calculations. It unveiled that NaCl/KCl could deactivate CrMn catalyst due to the decrease in specific surface area, electron transfer (Cr5++Mn3+↔Cr3++Mn4+), redox ability and oxygen vacancy and NH3/NO adsorption. In addition, NaCl cut off E-R mechanism reactions by inactivating surface Brønsted/Lewis acid sites. DFT calculations revealed that (1) Na and K could weaken MnO bond, (2) competitive adsorption between Cl and NH3 was a main reason weakening Lewis acid, (3) Cl adsorption was also a major cause diminishing Brønsted acid and oxygen vacancy, (4) Both Na and K seriously impeded NO adsorption/activation, (5) NaCl/KCl increased the reaction heat of H2O desorption (rate-determining step) in E-R mechanism reactions and KCl elevated its energy barrier in L-H mechanism reactions. Thus, this study provides the deep understanding of alkali metal poisoning and a well strategy to synthesize NH3-SCR catalysts with outstanding alkali metal resistance.
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Affiliation(s)
- Ninghan Wei
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, PR China
| | - Xiaomei Hu
- Guangdong Key Lab of Water & Air Pollution Control, Guangdong Province Engineering Laboratory for Air Pollution Control, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, PR China
| | - Cheng Zhao
- Guangdong Key Lab of Water & Air Pollution Control, Guangdong Province Engineering Laboratory for Air Pollution Control, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, PR China
| | - Zhangfa Tong
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, PR China
| | - Junge Yun
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, PR China
| | - Xueying Jiang
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, PR China
| | - Keju Wang
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, PR China
| | - Yun Zou
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, PR China.
| | - Zhihang Chen
- Guangdong Key Lab of Water & Air Pollution Control, Guangdong Province Engineering Laboratory for Air Pollution Control, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, PR China; College of Environment and Resources, Xiangtan University, Xiangtan 411105, PR China.
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Xiong Z, Zhang Y, Yang Q, Zhou F, Lu W, Shi H, Lu S. Promotional effect of nickel doping on the W/Fe2O3 catalyst for selective catalytic reduction of NO with NH3. MOLECULAR CATALYSIS 2023. [DOI: 10.1016/j.mcat.2022.112902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Xu Q, Li Z, Wang L, Zhan W, Guo Y, Guo Y. Understand the role of redox property and NO adsorption over MnFeOx for NH3-SCR. Catal Sci Technol 2022. [DOI: 10.1039/d1cy02203b] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Widening the operation temperature window of selective catalytic reduction NO by NH3 (NH3-SCR) is a challenge to meet the increasingly stringent emission control regulations of NOx. Hence, MnFeOx with different...
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Xu T, Liu X, Zhu T, Feng C, Hu Y, Tian M. New insights into the influence mechanism of H2O and SO2 on Pt-W/Ti catalysts for CO oxidation. Catal Sci Technol 2022. [DOI: 10.1039/d1cy01984h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of anatase TiO2 loaded with 0.1 wt.% Pt and n% WO3 (0.1Pt-nW/Ti-A, n=0, 1, 2, 5, 10) were prepared using the step-impregnation method. Among the catalysts, 0.1Pt-5W/Ti-A showed...
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