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Yang L, Wang Z, Xu B, Hu J, Pan D, Fan G, Zhang L, Zhou Z. A High-Performance Mn/TiO 2 Catalyst with a High Solid Content for Selective Catalytic Reduction of NO at Low-Temperatures. Molecules 2024; 29:3467. [PMID: 39124872 PMCID: PMC11313882 DOI: 10.3390/molecules29153467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2024] [Revised: 07/17/2024] [Accepted: 07/22/2024] [Indexed: 08/12/2024] Open
Abstract
Mn/TiO2 catalysts with varying solid contents were innovatively prepared by the sol-gel method and were used for selective catalytic reduction of NO at low temperatures using NH3 (NH3-SCR) as the reducing agent. Surprisingly, it was found that as the solid content of the sol increased, the catalytic activity of the developed Mn/TiO2 catalyst gradually increased, showing excellent catalytic performance. Notably, the Mn/TiO2 (50%) catalyst demonstrates outstanding denitration performance, achieving a 96% NO conversion rate at 100 °C under a volume hourly space velocity (VHSV) of 24,000 h-1, while maintaining high N2 selectivity and stability. It was discovered that as the solid content increased, the catalyst's specific surface area (SSA), surface Mn4+ concentration, chemisorbed oxygen, chemisorption of NH3, and catalytic reducibility all improved, thereby enhancing the catalytic efficiency of NH3-SCR in degrading NO. Moreover, NH3 at the Lewis acidic sites and NH4+ at the Bronsted acidic sites of the catalyst were capable of reacting with NO. Conversely, NO and NO2 adsorbed on the catalyst, along with bidentate and monodentate nitrates, were unable to react with NH3 at low temperatures. Consequently, the developed catalyst's low-temperature catalytic reaction mechanism aligns with the E-R mechanism.
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Affiliation(s)
| | | | - Bing Xu
- Hubei Provincial Engineering Technology Research Center of Agricultural and Sideline Resources, Chemical Engineering and Utilization, School of Chemistry and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, China; (L.Y.); (Z.W.); (J.H.); (D.P.); (G.F.); (L.Z.); (Z.Z.)
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Xu B, Wang Z, Hu J, Zhang L, Zhang Z, Liang H, Zhang Y, Fan G. Dy-Modified Mn/TiO 2 Catalyst Used for the Selective Catalytic Reduction of NO in Ammonia at Low Temperatures. Molecules 2024; 29:277. [PMID: 38202858 PMCID: PMC10781053 DOI: 10.3390/molecules29010277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 12/23/2023] [Accepted: 01/03/2024] [Indexed: 01/12/2024] Open
Abstract
A novel Mn/TiO2 catalyst, prepared through modification with the rare-earth metal Dy, has been employed for low-temperature selective catalytic reduction (SCR) denitrification. Anatase TiO2, with its large specific surface area, serves as the carrier. The active component MnOx on the TiO2 carrier is modified using Dy. DyxMn/TiO2, prepared via the impregnation method, exhibited remarkable catalytic performance in the SCR of NO with NH3 as the reducing agent at low temperatures. Experiments and characterization revealed that the introduction of a suitable amount of the rare-earth metal Dy can effectively enhance the catalyst's specific surface area and the gas-solid contact area in catalytic reactions. It also significantly increases the concentration of Mn4+, chemisorbed oxygen, and weak acid sites on the catalyst surface. This leads to a notable improvement in the reduction performance of the DyMn/TiO2 catalyst, ultimately contributing to the improvement of the NH3-SCR denitrification performance at low temperatures. At 100 °C and a space velocity of 24,000 h-1, the Dy0.1Mn/TiO2 catalyst can achieve a 98% conversion rate of NOx. Furthermore, its active temperature point decreases by 60 °C after the modification, highlighting exceptional catalytic efficacy at low temperatures. By doubling the space velocity, the NOx conversion rate of the catalyst can still reach 96% at 130 °C, indicating significant operational flexibility. The selectivity of N2 remained stable at over 95% before reaching 240 °C.
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Affiliation(s)
- Bing Xu
- Hubei Provincial Engineering Technology Research Center of Agricultural and Sideline Resources, Chemical Engineering and Utilization, School of Chemistry and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, China; (Z.W.); (J.H.); (L.Z.); (Z.Z.); (H.L.); (Y.Z.); (G.F.)
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Hu Y, Ding S, Tan C, Wu P, Li G, Wang S, Yang H, Zhang Y. Three-dimensionally ordered macroporous (3DOM) structure promoted the activity and H2O poisoning resistance of CeMn/3DOM-TiO2 catalyst in NH3-SCR. J RARE EARTH 2023. [DOI: 10.1016/j.jre.2023.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Tajnšek TK, Zabukovec Logar N, Mazaj M. Tuning Size and Properties of Zinc Ascorbate Metal-Organic Framework via Acid Modulation. Molecules 2022; 28:molecules28010253. [PMID: 36615446 PMCID: PMC9822160 DOI: 10.3390/molecules28010253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 12/31/2022] Open
Abstract
One of the biggest advantages of MOFs is the possibility of modifying their properties and tuning their inherent activity (i.e., sorption, storage, catalytic activity etc.). Textural properties can be tuned by manipulating process and compositional parameters, among which, the effect of additives can be even further distinguished among them based on the way they affect these properties. Beyond the effect that additives have on the size and morphology of nanoMOFs, there is also an effect on properties via creating point defects-missing linker and missing node defects. In this study, we investigated the effect of four monotopic acid modulators-formic, acetic, dichloroacetic and propionic acid, their concentration and the heating type (conventional and microwave-MW) on the size, morphology and textural properties of a recently discovered bioNICS1. It was confirmed that the proposed seesaw model for the controlled size of nanoMOF crystals is less applicable in the case of MW-assisted synthesis, in comparison to conventional heating. In the case of formic acid- and propionic acid-modified materials, we demonstrated that the type of additive plays a different role in crystal growth and generation of defects, implying high tunability being crucial for a material's structure-property performance optimization.
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Affiliation(s)
- Tia Kristian Tajnšek
- National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
- Faculty of Inorganic Chemistry and Technology, University of Ljubljana, Večna pot 113, 1000 Ljubljana, Slovenia
| | - Nataša Zabukovec Logar
- National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
- School of Science, University of Nova Gorica, Vipavska 13, 5000 Nova Gorica, Slovenia
| | - Matjaž Mazaj
- National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
- Correspondence:
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Zang P, Liu J, Liu X, Zhang G, Chen J, Li J, Zhang Y. Remarkable enhancement in the N 2 selectivity of NH 3-SCR over the CeNb 3Fe 0.3/TiO 2 catalyst in the presence of chlorobenzene. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:19309-19323. [PMID: 34713406 DOI: 10.1007/s11356-021-17116-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 10/15/2021] [Indexed: 06/13/2023]
Abstract
The simultaneous removal of NOx and dioxins is the frontier of environmental catalysis, which is still in the initial stage and poses several challenges. In this study, a series of CeNb3Fex/TiO2 (x = 0, 0.3, 0.6, and 1.0) catalysts were prepared by the sol-gel method and examined for the synergistic removal of NOx and CB. The CeNb3Fe0.3/TiO2 catalyst exhibits an optimum catalytic performance, with an NOx conversion greater than 95% at 260-380 °C. It also exhibits an optimal CB oxidation activity, in which CB promoted both the NOx conversion and N2 selectivity below 250 °C. Moreover, the more favorable ratios of Ce4+ to Ce3+ and plentiful surface-adsorbed oxygen species are the reasons why CeNb3Fe0.3/TiO2 catalyst has better catalytic activity than other catalysts at the lower temperature. Simultaneously, owing to the modulation of Fe to the redox properties of Ce and Nb, the large number of oxygen vacancies and acid sites was generated, and the CeNb3Fe0.3/TiO2 catalyst is beneficial to NOx reduction and CB oxidation. Furthermore, the results of in situ DRIFTS study reveal the NH3-SCR reactions over CeNb3Fe0.3/TiO2 catalysts are mainly conformed to by the L-H mechanism (< 350 °C) and E-R mechanism (> 350 °C), respectively, and the multi-pollutant conversion mechanism in the synergistic reaction was systematically studied.
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Affiliation(s)
- Pengchao Zang
- College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan, 030024, People's Republic of China
- State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, People's Republic of China
| | - Jun Liu
- College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan, 030024, People's Republic of China.
- State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, People's Republic of China.
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, National Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.
| | - Xiaoqing Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, National Engineering, Tsinghua University, Beijing, 100084, People's Republic of China
- School of Environment and Safety Engineering, North University of China, Taiyuan, 030051, Shanxi, People's Republic of China
| | - Guojie Zhang
- College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan, 030024, People's Republic of China.
- State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, People's Republic of China.
| | - Jianjun Chen
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, National Engineering, Tsinghua University, Beijing, 100084, People's Republic of China
| | - Junhua Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, National Engineering, Tsinghua University, Beijing, 100084, People's Republic of China
| | - Yongfa Zhang
- College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan, 030024, People's Republic of China
- State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, People's Republic of China
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Li X, Han Z, Wang X, Yang S, Liu G, Gao Y, Li C. Acid treatment of ZrO2-supported CeO2 catalysts for NH3-SCR of NO: Influence on surface acidity and reaction mechanism. J Taiwan Inst Chem Eng 2022. [DOI: 10.1016/j.jtice.2021.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Han Z, Du H, Xu D, Gao Y, Yang S, Song L, Dong J, Pan X. Fe and Mn mixed oxide catalysts supported on Sn-modified TiO 2 for the selective catalytic reduction of NO with NH 3 at low temperature. NEW J CHEM 2022. [DOI: 10.1039/d1nj05290j] [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
FeMn/SnxTiO2 catalysts were synthesized by introducing Sn as an additive to modify TiO2 supports, and the Sn doping could improve the SO2 tolerance and low-temperature SCR activity significantly.
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Affiliation(s)
- Zhitao Han
- Marine Engineering College, Dalian Maritime University, Dalian 116026, China
| | - Huan Du
- China Waterborne Transport Research Institute, Beijing 100088, China
| | - Duo Xu
- Marine Engineering College, Dalian Maritime University, Dalian 116026, China
| | - Yu Gao
- Marine Engineering College, Dalian Maritime University, Dalian 116026, China
| | - Shaolong Yang
- School of Naval Architecture and Ocean Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Liguo Song
- Marine Engineering College, Dalian Maritime University, Dalian 116026, China
| | - Jingming Dong
- Marine Engineering College, Dalian Maritime University, Dalian 116026, China
| | - Xinxiang Pan
- Marine Engineering College, Dalian Maritime University, Dalian 116026, China
- School of Electronic and Information Technology, Guangdong Ocean University, Zhanjiang 524088, China
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Li X, Han Z, Shi Q, Wang X, Wu X, Gao Y, Li C, Liu G. Characterization of WMnCeTiO x catalysts prepared by different methods for the selective reduction of NO with NH 3. NEW J CHEM 2021. [DOI: 10.1039/d1nj03891e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
WMnCeTiOx(CP) catalysts showed excellent NH3-SCR activity and better SO2 tolerance.
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Affiliation(s)
- Xiaodi Li
- School of Resources and Environmental Sciences, XinJiang University, Wulumuqi, 830000, China
| | - Zhitao Han
- Marine Engineering College, Dalian Maritime University, No. 1, Linghai Road, Dalian 116026, China
- Liaoning Research Center for Marine Internal Combustion Engine Energy-Saving, Dalian 116026, China
| | - Qingdong Shi
- School of Resources and Environmental Sciences, XinJiang University, Wulumuqi, 830000, China
| | - Xinxin Wang
- Marine Engineering College, Dalian Maritime University, No. 1, Linghai Road, Dalian 116026, China
| | - Xitian Wu
- Marine Engineering College, Dalian Maritime University, No. 1, Linghai Road, Dalian 116026, China
| | - Yu Gao
- Marine Engineering College, Dalian Maritime University, No. 1, Linghai Road, Dalian 116026, China
| | - Chenglong Li
- Marine Engineering College, Dalian Maritime University, No. 1, Linghai Road, Dalian 116026, China
| | - Gang Liu
- Marine Engineering College, Dalian Maritime University, No. 1, Linghai Road, Dalian 116026, China
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