1
|
Jia L, Zhang L, Liu B, Cheng H, Li H, Zhao Z, Zhu W, Song W, Liu J, Liu J. Interface Induced by Hydrothermal Aging Boosts the Low-Temperature Activity of Cu-SSZ-13 for Selective Catalytic Reduction of NO x. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 39138907 DOI: 10.1021/acs.est.4c04101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2024]
Abstract
Hitherto, sulfur poisoning and hydrothermal aging have still been the challenges faced in practical applications of the Cu-SSZ-13 catalyst for the selective catalytic reduction (SCR) of NOx from diesel engine exhaust. Here, we elaborately design and conduct an in-depth investigation of the synthetic effects of hydrothermal aging and SO2 poisoning on pristine Cu-SSZ-13 and Cu-SSZ-13@Ce0.75Zr0.25O2 core@shell structure catalysts (Cu@CZ). It has been discovered that Cu@CZ susceptible to 750 °C with 5 vol % H2O followed by 200 ppm SO2 with 5 vol % H2O (Cu@CZ-A-S) could still maintain nearly 100% NOx conversion across the significantly wider temperature region of 200-425 °C, which is remarkably broader than that of the Cu-SSZ-13-A-S (300-400 °C) counterpart. The experimental results show that the hydrothermal aging process results in the migration of highly active Cu species within the cage of Cu-SSZ-13 to the CZ surface, forming CuO/CZ with abundant interfaces, which significantly enhances the adsorption and subsequent activation of NO, leading to the generation of reactive N2O3 and HONO intermediates. Moreover, density functional theory (DFT) calculations reveal that the H of the HONO* species can function as Brønsted acid sites, effectively adsorbing NH3 to generate the active NH4NO2* intermediate, which readily decomposes into N2 and H2O. Furthermore, this pathway is the rate-determining step with an energy barrier of 0.93 eV, notably lower than that of the "standard SCR" pathway (1.42 eV). Therefore, the formation of the new CuO/CZ interface profoundly boosts the low-temperature NH3-SCR activity and improves the coresistance of the Cu@CZ catalyst to sulfur poisoning and hydrothermal aging.
Collapse
Affiliation(s)
- Lingfeng Jia
- School of Chemistry and Chemical Engineering, Institution for Energy Research, Jiangsu University, Zhenjiang 212013, P. R. China
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum (Beijing), Beijing 102249, P. R. China
| | - Li Zhang
- CATARC Automotive Test Center (Tianjin) Co., Ltd, China Automotive Technology & Research Center Co., Ltd., Tianjin 300300, P. R. China
| | - Bing Liu
- Department of Chemical Engineering, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, P. R. China
| | - Huifang Cheng
- School of Chemistry and Chemical Engineering, Institution for Energy Research, Jiangsu University, Zhenjiang 212013, P. R. China
| | - Huiquan Li
- Anhui Provincial Key Laboratory for Degradation and Monitoring of Pollution of the Environment, Fuyang Normal University, Fuyang 236037, P. R. China
| | - Zhen Zhao
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum (Beijing), Beijing 102249, P. R. China
| | - Wenshuai Zhu
- School of Chemistry and Chemical Engineering, Institution for Energy Research, Jiangsu University, Zhenjiang 212013, P. R. China
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum (Beijing), Beijing 102249, P. R. China
| | - Weiyu Song
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum (Beijing), Beijing 102249, P. R. China
| | - Jian Liu
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum (Beijing), Beijing 102249, P. R. China
- Laboratory of Heavy Oil at Karamay, China University of Petroleum (Beijing) at Karamay, Karamay 834000, P. R. China
| | - Jixing Liu
- School of Chemistry and Chemical Engineering, Institution for Energy Research, Jiangsu University, Zhenjiang 212013, P. R. China
| |
Collapse
|
2
|
An P, Gao C, Zhu X, Wang B, Xuan Y, Liang Y, Xia S, Si W, Wang D, Peng Y, Li J. Phosphorus-Water Interaction Drives Active Center Evolution into the Water-Adaptive Structure in the High-Humidity NH 3-SCR Reaction. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 39058552 DOI: 10.1021/acs.est.4c03593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Abstract
The impact of water on catalyst activity remains inconclusive due to its dependence on the specific reaction environment. To maximize the exploitation of water's promoting effect, we employed ammonia selective catalytic reduction (NH3-SCR) as a probe reaction and proposed a phosphorus modification strategy for Cu-ZSM-5 catalysts. The objective of this approach was to construct water-adaptive microstructures through directional arrangement. To investigate the effect of phosphorus on the transformation of framework copper sites in humid environments, we conducted comprehensive characterizations and density functional theory calculation. Results reveal that water molecules cleave the oxygen bridges between phosphorus oxide and copper, leading to the formation of active isolated [Cu(OH)]+ groups and phosphate. The phosphate species weaken the interaction between exchanged Cu2+ groups and the zeolite framework, leading to the generation of highly migratory hydrated Cu2+ species. This work will potentially guide the rational design of water-adaptive catalysts for gas pollution abatement in a humid environment.
Collapse
Affiliation(s)
- Penghao An
- School of Energy and Power Engineering, Shandong University, Jinan, Shandong 250061, China
| | - Chuan Gao
- School of Energy and Power Engineering, Shandong University, Jinan, Shandong 250061, China
- State Key Joint Laboratory of Environment Simulation and Pollution Control, National Engineering Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, Tsinghua University, Beijing 100084, China
| | - Xiao Zhu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, National Engineering Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, Tsinghua University, Beijing 100084, China
| | - Bin Wang
- School of Energy and Power Engineering, Shandong University, Jinan, Shandong 250061, China
| | - Yue Xuan
- School of Energy and Power Engineering, Shandong University, Jinan, Shandong 250061, China
| | - Yanjie Liang
- School of Energy and Power Engineering, Shandong University, Jinan, Shandong 250061, China
| | - Sunwen Xia
- School of Energy and Power Engineering, Shandong University, Jinan, Shandong 250061, China
| | - Wenzhe Si
- State Key Joint Laboratory of Environment Simulation and Pollution Control, National Engineering Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, Tsinghua University, Beijing 100084, China
| | - Dong Wang
- School of Energy and Power Engineering, Shandong University, Jinan, Shandong 250061, China
| | - Yue Peng
- State Key Joint Laboratory of Environment Simulation and Pollution Control, National Engineering Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, Tsinghua University, Beijing 100084, China
| | - Junhua Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control, National Engineering Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, Tsinghua University, Beijing 100084, China
| |
Collapse
|
3
|
Bian C, Luo X, Chen X, Liu R, Li J, Zhu G, Xu H, Han S, Zhu J, Zhu L. One-Pot Synthesis of Ce-SSZ-39 Zeolite with Performance in the NH 3-SCR Reaction. Inorg Chem 2024; 63:10798-10808. [PMID: 38781309 DOI: 10.1021/acs.inorgchem.4c01509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Cu-SSZ-39 zeolite with 8-membered rings is regarded as a very promising catalyst in the NH3-SCR reaction, but its hydrothermal stability still remains to be improved. One of the solutions to promote hydrothermal stability is the insertion of rare earth elements in the product. Nevertheless, normal ion exchange of rare earth elements limits their contents in the zeolite product due to their large hydrated ionic radius and alkaline environment under hydrothermal conditions. Herein, we for the first time present a new method for the one-pot synthesis of Ce-SSZ-39 zeolite under solvent-free conditions. The key to success is the use of Ce-FAU zeolite as a precursor. The obtained product shows good crystallinity, sheet-like morphology, large BET surface area, and 4-coordinated Al species. Detailed investigations illustrate that Ce species in the Cu/Ce-SSZ-39 zeolite micropore can prevent the dealumination and thus formation of CuAlOx species during hydrothermal aging at 850 °C for 16 h, giving the excellent hydrothermal stability and thus showing the excellent catalytic performance in the NH3-SCR reaction. One-pot synthesis of Ce-SSZ-39 zeolite with excellent catalytic performance might open a new door for developing very efficient selective catalytic reduction (SCR) catalysts in near future.
Collapse
Affiliation(s)
- Chaoqun Bian
- Pharmaceutical and Material Engineering School, Jinhua Polytechnic, Jinhua 321000, P. R. China
| | - Xiaohui Luo
- Pharmaceutical and Material Engineering School, Jinhua Polytechnic, Jinhua 321000, P. R. China
| | - Xiao Chen
- Pharmaceutical and Material Engineering School, Jinhua Polytechnic, Jinhua 321000, P. R. China
| | - Rongrong Liu
- Pharmaceutical and Material Engineering School, Jinhua Polytechnic, Jinhua 321000, P. R. China
| | - Jingqiu Li
- College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, P. R. China
| | - Gaoyuan Zhu
- Pharmaceutical and Material Engineering School, Jinhua Polytechnic, Jinhua 321000, P. R. China
| | - Hao Xu
- College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310015, P. R. China
| | - Shichao Han
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, P. R. China
| | - Jie Zhu
- College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, P. R. China
| | - Longfeng Zhu
- College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, P. R. China
| |
Collapse
|
4
|
Fu Y, Ding W, Lei H, Sun Y, Du J, Yu Y, Simon U, Chen P, Shan Y, He G, He H. Spatial Distribution of Brønsted Acid Sites Determines the Mobility of Reactive Cu Ions in the Cu-SSZ-13 Catalyst during the Selective Catalytic Reduction of NO x with NH 3. J Am Chem Soc 2024; 146:11141-11151. [PMID: 38600025 DOI: 10.1021/jacs.3c13725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
The formation of dimer-Cu species, which serve as the active sites of the low-temperature selective catalytic reduction of NOx with NH3 (NH3-SCR), relies on the mobility of CuI species in the channels of the Cu-SSZ-13 catalysts. Herein, the key role of framework Brønsted acid sites in the mobility of reactive Cu ions was elucidated via a combination of density functional theory calculations, in situ impedance spectroscopy, and in situ diffuse reflectance ultraviolet-visible spectroscopy. When the number of framework Al sites decreases, the Brønsted acid sites decrease, leading to a systematic increase in the diffusion barrier for [Cu(NH3)2]+ and less formation of highly reactive dimer-Cu species, which inhibits the low-temperature NH3-SCR reactivity and vice versa. When the spatial distribution of Al sites is uneven, the [Cu(NH3)2]+ complexes tend to migrate from an Al-poor cage to an Al-rich cage (e.g., cage with paired Al sites), which effectively accelerates the formation of dimer-Cu species and hence promotes the SCR reaction. These findings unveil the mechanism by which framework Brønsted acid sites influence the intercage diffusion and reactivity of [Cu(NH3)2]+ complexes in Cu-SSZ-13 catalysts and provide new insights for the development of zeolite-based catalysts with excellent SCR activity by regulating the microscopic spatial distribution of framework Brønsted acid sites.
Collapse
Affiliation(s)
- Yu Fu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Wenqing Ding
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang 330031, China
| | - Huarong Lei
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
- Institute of Inorganic Chemistry, RWTH Aachen University, Aachen 52074, Germany
| | - Yu Sun
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jinpeng Du
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Yunbo Yu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ulrich Simon
- Institute of Inorganic Chemistry, RWTH Aachen University, Aachen 52074, Germany
| | - Peirong Chen
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Yulong Shan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Guangzhi He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
5
|
Pan Y, Li N, Wu C, Zhou Q, Li K. Unlocking the Potential of Metal-Doping Fe 2O 3/Rice Husk Ash Catalysts for Low-Temperature CO-SCR Enhancement. ACS OMEGA 2024; 9:16621-16630. [PMID: 38617651 PMCID: PMC11007803 DOI: 10.1021/acsomega.4c00593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 01/30/2024] [Indexed: 04/16/2024]
Abstract
Transition metal oxides are efficient bifunctional catalysts for the selective catalytic reduction (SCR) of nitrogen oxides (NOx) using CO. Nonetheless, their poor activity at lower temperatures constrains broader industrial application. Herein, we propose an optimized Fe2O3-based catalyst through strategic metal doping with Cu, Co, or Ce, which engenders a harmonious balance for the synergistic removal of CO and NOx. Among the developed catalysts, Co-doped Fe2O3, supported by rice husk ash, demonstrates superior low-temperature CO-SCR activity, achieving CO and NOx conversion ratios and N2 selectivity above 98.5% at 100-500 °C. The enhanced catalytic performance is attributed to the catalyst's improved redox properties and acidity, engendered by strong Fe-Ox-Co interactions. Furthermore, the CO-SCR reaction adheres to the Langmuir-Hinshelwood and Eley-Rideal mechanisms. Our findings shed light on the future industrial application of low-temperature CO and NOx near-zero emission technology and provide a strategy for the design of low-cost SCR catalysts.
Collapse
Affiliation(s)
- Yuqing Pan
- State
Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China
| | - Na Li
- State
Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China
| | - Chenyang Wu
- State
Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China
| | - Qulan Zhou
- State
Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China
| | - Ke Li
- Institute
of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| |
Collapse
|
6
|
Chang C, Yan Z, Zhang C, Zhang Y, Jiang M, Ruan L, Xiao M, Yu Y, He H. Design of Ca-type todorokite catalysts with highly active for the selective reduction of NO x by NH 3 at low temperatures. J Environ Sci (China) 2024; 138:697-708. [PMID: 38135432 DOI: 10.1016/j.jes.2023.04.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/17/2023] [Accepted: 04/23/2023] [Indexed: 12/24/2023]
Abstract
Ca-type todorokite catalysts were designed and prepared by a simple redox method and applied to the selective reduction of NOx by NH3 (NH3-SCR) for the first time. Compared with the Na-type manjiroite prepared by the same method, the todorokite catalysts with different Mn/Ca ratios showed greatly improved catalytic activity for NOx reduction. Among them, Mn8Ca4 catalyst exhibited the best NH3-SCR performance, achieving 90% NOx conversion within temperature range of 70-275°C and having a high sulphur resistance. Compared to the Na-type manjiroite sample, Ca-type todorokite catalysts possessed an increased size of tunnel, resulting in a larger specific surface area. As increased the amounts of Ca doping, the Na content in Ca-type todorokite catalysts significantly decreased, providing larger amounts of Brønsted acid sites for NH3 adsorption to produce NH4+. The NH4+ species were highly active for reaction with NO + O2, playing a determining role in NH3-SCR process at low temperatures. Meanwhile, larger amounts of surface adsorbed oxygen contained over the Ca-doping samples than that over Na-type manjiroite, promoting the oxidation of NO and fast SCR processes. Over the Ca-type todorokite catalysts, furthermore, nitrates produced during the flow of NO + O2, were more active for reaction with NH3 than that over Na-type manjiroite, benefiting the occurrence of NH3-SCR process. This study provides novel insights into the design of NH3-SCR catalysts with high performance.
Collapse
Affiliation(s)
- Chuang Chang
- School of Rare Earths, University of Science and Technology of China, Hefei 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China
| | - Zidi Yan
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China
| | - Chunlei Zhang
- School of Rare Earths, University of Science and Technology of China, Hefei 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China
| | - Yanshuang Zhang
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China
| | - Miao Jiang
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China
| | - Luna Ruan
- School of Rare Earths, University of Science and Technology of China, Hefei 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China
| | - Min Xiao
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China
| | - Yunbo Yu
- School of Rare Earths, University of Science and Technology of China, Hefei 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Hong He
- School of Rare Earths, University of Science and Technology of China, Hefei 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| |
Collapse
|
7
|
Wei Y, Wang S, Chen M, Han J, Yang G, Wang Q, Di J, Li H, Wu W, Yu J. Coaxial 3D Printing of Zeolite-Based Core-Shell Monolithic Cu-SSZ-13@SiO 2 Catalysts for Diesel Exhaust Treatment. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2302912. [PMID: 37177904 DOI: 10.1002/adma.202302912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/01/2023] [Indexed: 05/15/2023]
Abstract
Core-shell catalysts with functional shells can increase the activity and stability of the catalysts in selective catalytic reduction of NOx with ammoniax. However, the conventional approaches based on multistep fabrication for core-shell structures encounter persistent restrictions regarding strict synthesis conditions and limited design flexibility. Herein, a facile coaxial 3D printing strategy is for the first time developed to construct zeolite-based core-shell monolithic catalysts with interconnected honeycomb structures, in which the hydrophilic noncompact silica serves as shell and Cu-SSZ-13 zeolite acts as core. Compared to a Cu-SSZ-13 monolith which suffers from the interfacial diffusion, the SiO2 shell layer can increase the accessibility of active sites over Cu-SSZ-13@SiO2, resulting in a 10-20% higher NO conversion at200-550 °C under 300 000 cm3 g-1 h-1. Meanwhile, a thicker SiO2 shell enhances the hydrothermal stability of the aged catalyst by inhibiting the dealumination and the formation of CuOx. Other representative monolithic catalysts with different topological zeolites as shell and diverse metal oxides as the core can be also realized by this coaxial 3D printing. This strategy allows multiple porous materials to be directly integrated, which allows for flexible design and fabrication of various core-shell monolithic catalysts with customized functionalities.
Collapse
Affiliation(s)
- Yingzhen Wei
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China
| | - Shuang Wang
- Henan Province Function-Oriented Porous Materials Key Laboratory, College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang, 471934, China
| | - Mengyang Chen
- School of Pharmaceutical and Chemical Engineering, Taizhou University, Taizhou, 317000, China
| | - Jinfeng Han
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China
| | - Guoju Yang
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China
| | - Qifei Wang
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China
| | - Jiancheng Di
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China
| | - Hongli Li
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China
| | - Wenzheng Wu
- School of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130025, China
| | - Jihong Yu
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China
- International Center of Future Science, Jilin University, Changchun, 130012, China
| |
Collapse
|
8
|
Duan R, Li Z, Fu Y, Shan Y, Yu Y, He G, He H. Combined Experimental and Density Functional Theory Study on the Mechanism of the Selective Catalytic Reduction of NO with NH 3 over Metal-Free Carbon-Based Catalysts. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:5598-5605. [PMID: 38466913 DOI: 10.1021/acs.est.4c00584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Metal-free carbon-based catalysts are attracting much attention in the low-temperature selective catalytic reduction of NOx with NH3 (NH3-SCR). However, the mechanism of the NH3-SCR reaction on carbon-based catalysts is still controversial, which severely limits the development of carbon-based SCR catalysts. Herein, we successfully reconstructed carbon-based catalysts through oxidation treatment with nitric acid, thereby enhancing their low-temperature activity in NH3-SCR. Combining experimental results and density functional theory (DFT) calculations, we proposed a previously unreported NH3-SCR reaction mechanism over carbon-based catalysts. We demonstrated that C-OH and C-O-C groups not only effectively activate NH3 but also remarkedly promote the decomposition of intermediate NH2NO. This study enhances the understanding of the NH3-SCR mechanism on carbon-based catalysts and paves the way to develop low-temperature metal-free SCR catalysts.
Collapse
Affiliation(s)
- Rucheng Duan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhuocan Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Fu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yulong Shan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yunbo Yu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Guangzhi He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| |
Collapse
|
9
|
Han J, Li J, Zhao W, Li L, Chen M, Ge X, Wang S, Liu Q, Mei D, Yu J. Cu-OFF/ERI Zeolite: Intergrowth Structure Synergistically Boosting Selective Catalytic Reduction of NO x with NH 3. J Am Chem Soc 2024; 146:7605-7615. [PMID: 38467427 DOI: 10.1021/jacs.3c13855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Cu-SSZ-13 has been commercialized for selective catalytic reduction with ammonia (NH3-SCR) to remove NOx from diesel exhaust. As its synthesis usually requires toxic and costly organic templates, the discovery of alternative Cu-based zeolite catalysts with organotemplate-free synthesis and comparable or even superior NH3-SCR activity to that of Cu-SSZ-13 is of great academic and industrial significance. Herein, we demonstrated that Cu-T with an intergrowth structure of offretite (OFF) and erionite (ERI) synthesized by an organotemplate-free method showed better catalytic performance than Cu-ERI and Cu-OFF as well as Cu-SSZ-13. Structure characterizations and density functional theory calculations indicated that the intergrowth structure promoted more isolated Cu2+ located at the 6MR of the intergrowth interface, resulting in a better hydrothermal stability of Cu-T than Cu-ERI and Cu-OFF. Strikingly, the low-temperature activity of Cu-T significantly increased after hydrothermal aging, while that of Cu-ERI and Cu-OFF substantially decreased. Based on in situ diffuse reflectance infrared Fourier transform spectra analysis and density functional theory calculations, the reason can be attributed to the fact that NH4NO3 formed on the CuxOy species within ERI polymorph of Cu-T underwent a fast SCR reaction pathway with the assistance of Brønsted acid sites at the intergrowth interfaces under standard SCR reaction conditions. Significantly, Cu-T exhibited a wider temperature window at a catalytic activity of over 90% than Cu-SSZ-13 (175-550 vs 175-500 °C for fresh and 225-500 vs 250-400 °C for hydrothermal treatment). This work provides a new direction for the design of high-performance NH3-SCR catalysts in terms of the interplay of the intergrowth structure of zeolites.
Collapse
Affiliation(s)
- Jinfeng Han
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Technology, Tianjin University, Tianjin 300350, P. R. China
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, P. R. China
| | - Junyan Li
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China
- Center for High-Resolution Electron Microscopy (CℏEM), School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, P. R. China
| | - Wenru Zhao
- School of Materials Science and Engineering, Tiangong University, Tianjin 300387, P. R. China
| | - Lin Li
- Electron Microscopy Center, Jilin University, Changchun 130012, P. R. China
| | - Mengyang Chen
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China
- International Center of Future Science, Jilin University, Changchun 130012, P. R. China
| | - Xin Ge
- Electron Microscopy Center, Jilin University, Changchun 130012, P. R. China
| | - Sen Wang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, P. R. China
| | - Qingling Liu
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Technology, Tianjin University, Tianjin 300350, P. R. China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, P. R. China
| | - Donghai Mei
- School of Materials Science and Engineering, Tiangong University, Tianjin 300387, P. R. China
| | - Jihong Yu
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China
- International Center of Future Science, Jilin University, Changchun 130012, P. R. China
| |
Collapse
|
10
|
Wang H, Gao C, Wang R, Yuan J, Zhou B, Si W, Li J, Peng Y. Influence of Oxygen Vacancy-Induced Coordination Change on Pd/CeO 2 for NO Reduction. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:2133-2143. [PMID: 38237035 DOI: 10.1021/acs.est.3c08582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2024]
Abstract
The byproduct formation in environmental catalysis is strongly influenced by the chemical state and coordination of catalysts. Herein, two Pd/CeO2 catalysts (PdCe-350 and PdCe-800) with varying oxygen vacancies (Ov) and coordination numbers (CN) of Pd were prepared to investigate the mechanism of N2O and NH3 formation during NO reduction by CO. PdCe-350 exhibits a higher density of Ov and Pd sites with higher CN, leading to an enhanced metal-support interaction by electron transformation from the support to Pd. Consequently, PdCe-350 displayed increased levels of byproduct formation. In situ spectroscopies under dry and wet conditions revealed that at low temperatures, the N2O formation strongly correlated with the Ov density through the decomposition of chelating nitro species on PdCe-350. Conversely, at high temperatures, it was linked to the reactivity of Pd species, primarily facilitated by monodentate nitrates on PdCe-800. In terms of NH3 formation, its occurrence was closely associated with the activation of H2O and C3H6, since a water-gas shift or hydrocarbon reforming could provide hydrogen. Both bridging and monodentate nitrates showed activity in NH3 formation, while hyponitrites were identified as key intermediates for both catalysts. The insights provide a fundamental understanding of the intricate relationship among the local coordination of Pd, surface Ov, and byproduct distribution.
Collapse
Affiliation(s)
- Houlin Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Chuan Gao
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Rong Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jin Yuan
- College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Bin Zhou
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Wenzhe Si
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Junhua Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Yue Peng
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| |
Collapse
|
11
|
Yan Q, Xiao J, Gui R, Chen Z, Li Y, Zhu T, Wang Q, Xin Y. Mechanistic Insight into the Promotion of the Low-Temperature NH 3-SCR Activity over NiMnFeO x LDO Catalysts: A Combined Experimental and DFT Study. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:20708-20717. [PMID: 38032314 DOI: 10.1021/acs.est.3c06849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Abstract
Mn-based catalysts have attracted much attention in the field of the low-temperature NH3 selective catalytic reduction (NH3-SCR) of NO. However, their poor SO2 resistance, low N2 selectivity, and narrow operation window limit the industrial application of Mn-based oxide catalysts. In this work, NiMnFeOx catalysts were prepared by the layered double hydroxide (LDH)-derived oxide method, and the optimized Ni0.5Mn0.5Fe0.5Ox catalyst had the best denitration activity, excellent N2 selectivity, a wider active temperature range (100-250 °C), higher thermal stability, and better H2O and/or SO2 resistance. A transient reaction revealed that Ni0.5Mn0.5Fe0.5Ox inhibited the NH3 + O2 + NOx pathway to generate N2O, which may be the main reason for its improved N2 selectivity. Combining experimental measurements and density functional theory (DFT) calculations, we elucidated at the atomic level that sulfated NiMnFeOx (111) induces the adjustment of the acidity/basicity of up and down spins and the ligand field reconfiguration of the Mn sites, which improves the overall reactivity of NiMnFeOx catalysts. This work provides atomic-level insights into the promotion of NH3-SCR activity by NiMnFeOx composite oxides, which are important for the practical design of future low-temperature SCR technologies.
Collapse
Affiliation(s)
- Qinghua Yan
- Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, P.R. China
| | - Jiewen Xiao
- College of Environmental Science and Engineering, Beijing Forestry University, 35 Qinghua East Road, Haidian District, Beijing 100083, P.R. China
| | - Rongrong Gui
- College of Environmental Science and Engineering, Beijing Forestry University, 35 Qinghua East Road, Haidian District, Beijing 100083, P.R. China
| | - Zhenyu Chen
- Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, P.R. China
| | - Yuran Li
- Research Center for Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Tingyu Zhu
- Research Center for Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Qiang Wang
- College of Environmental Science and Engineering, Beijing Forestry University, 35 Qinghua East Road, Haidian District, Beijing 100083, P.R. China
| | - Yanjun Xin
- Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, P.R. China
| |
Collapse
|
12
|
Li Z, Xiao J, Gao Y, Gui R, Wang Q. Design of Bifunctional Cu-SSZ-13@Mn 2Cu 1Al 1O x Core-Shell Catalyst with Superior Activity for the Simultaneous Removal of VOCs and NO x. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:20326-20338. [PMID: 37955373 DOI: 10.1021/acs.est.3c04421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
Synchronous control of volatile organic compounds (VOCs) and nitrogen oxides (NOx) is of great importance for ozone and PM2.5 pollution control. Balancing VOC oxidation and the NH3-SCR reaction is the key to achieving the simultaneous removal of these two pollutants. In this work, a vertically oriented Mn2Cu1Al1Ox nanosheet is grown in situ on the surface of Cu-SSZ-13 to synthesize a core-shell bifunctional catalyst (Cu-SSZ-13@Mn2Cu1Al1Ox) with multiple active sites. The optimized Cu-SSZ-13@Mn2Cu1Al1Ox catalyst delivered excellent performance for the simultaneous removal of VOCs and NOx with both 100% conversion at 300 °C in the presence of 5% water vapor. Physicochemical characterization and density functional theory (DFT) calculations revealed that Cu-SSZ-13@Mn2Cu1Al1Ox possesses more surface acidity and oxygen vacancies. The charge transfer between the core and shell is the intrinsic reason for the improved activity for both VOC and NOx removal. The molecular orbital theory is used to explain the different adsorption energies due to the different bonding modes between the core-shell and mixed individual catalysts. This work provides a novel strategy for designing efficient catalysts for the simultaneous removal of VOCs and NOx or other multiple pollutants.
Collapse
Affiliation(s)
- Zhe Li
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
- Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Jiewen Xiao
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
- Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Yanshan Gao
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
- Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Rongrong Gui
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
- Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Qiang Wang
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
- Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| |
Collapse
|
13
|
Chen D, Khetan A, Lei H, Rizzotto V, Yang JY, Jiang J, Sun Q, Peng B, Chen P, Palkovits R, Ye D, Simon U. Copper Site Motion Promotes Catalytic NO x Reduction under Zeolite Confinement. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:16121-16130. [PMID: 37842921 DOI: 10.1021/acs.est.3c03422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Ammonia-mediated selective catalytic reduction (NH3-SCR) is currently the key approach to abate nitrogen oxides (NOx) emitted from heavy-duty lean-burn vehicles. The state-of-art NH3-SCR catalysts, namely, copper ion-exchanged chabazite (Cu-CHA) zeolites, perform rather poorly at low temperatures (below 200 °C) and are thus incapable of eliminating effectively NOx emissions under cold-start conditions. Here, we demonstrate a significant promotion of low-temperature NOx reduction by reinforcing the dynamic motion of zeolite-confined Cu sites during NH3-SCR. Combining complex impedance-based in situ spectroscopy (IS) and extended density-functional tight-binding molecular dynamics simulation, we revealed an environment- and temperature-dependent nature of the dynamic Cu motion within the zeolite lattice. Further coupling in situ IS with infrared spectroscopy allows us to unravel the critical role of monovalent Cu in the overall Cu mobility at a molecular level. Based on these mechanistic understandings, we elicit a boost of NOx reduction below 200 °C by reinforcing the dynamic Cu motion in various Cu-zeolites (Cu-CHA, Cu-ZSM-5, Cu-Beta, etc.) via facile postsynthesis treatments, either in a reductive mixture at low temperatures (below 250 °C) or in a nonoxidative atmosphere at high temperatures (above 450 °C).
Collapse
Affiliation(s)
- Dongdong Chen
- National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, School of Environment and Energy, South China University of Technology, 510006 Guangzhou, China
| | - Abhishek Khetan
- Multiscale Modelling of Heterogeneous Catalysis in Energy Systems, RWTH Aachen University, Schinkelstrasse 8, 52062 Aachen, Germany
| | - Huarong Lei
- National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, School of Environment and Energy, South China University of Technology, 510006 Guangzhou, China
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen Germany
| | - Valentina Rizzotto
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen Germany
| | - Jia-Yue Yang
- Optics & Thermal Radiation Research Center, Shandong University, 266237 Qingdao, China
| | - Jiuxing Jiang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, 510275 Guangzhou, China
| | - Qiming Sun
- Innovation Center for Chemical Sciences, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123 Suzhou, China
| | - Baoxiang Peng
- Laboratory of Industrial Chemistry, Ruhr University Bochum, 44780 Bochum, Germany
| | - Peirong Chen
- National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, School of Environment and Energy, South China University of Technology, 510006 Guangzhou, China
| | - Regina Palkovits
- Chair of Heterogeneous Catalysis and Chemical Technology, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany
| | - Daiqi Ye
- National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, School of Environment and Energy, South China University of Technology, 510006 Guangzhou, China
| | - Ulrich Simon
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen Germany
| |
Collapse
|
14
|
Lei H, Chen D, Yang JY, Khetan A, Jiang J, Peng B, Simon U, Ye D, Chen P. Revealing the Formation and Reactivity of Cage-Confined Cu Pairs in Catalytic NO x Reduction over Cu-SSZ-13 Zeolites by In Situ UV-Vis Spectroscopy and Time-Dependent DFT Calculation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:12465-12475. [PMID: 37556316 DOI: 10.1021/acs.est.3c00458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
The low-temperature mechanism of chabazite-type small-pore Cu-SSZ-13 zeolite, a state-of-the-art catalyst for ammonia-assisted selective reduction (NH3-SCR) of toxic NOx pollutants from heavy-duty vehicles, remains a debate and needs to be clarified for further improvement of NH3-SCR performance. In this study, we established experimental protocols to follow the dynamic redox cycling (i.e., CuII ↔ CuI) of Cu sites in Cu-SSZ-13 during low-temperature NH3-SCR catalysis by in situ ultraviolet-visible spectroscopy and in situ infrared spectroscopy. Further integrating the in situ spectroscopic observations with time-dependent density functional theory calculations allows us to identify two cage-confined transient states, namely, the O2-bridged Cu dimers (i.e., μ-η2:η2-peroxodiamino dicopper) and the proximately paired, chemically nonbonded CuI(NH3)2 sites, and to confirm the CuI(NH3)2 pair as a precursor to the O2-bridged Cu dimer. Comparative transient experiments reveal a particularly high reactivity of the CuI(NH3)2 pairs for NO-to-N2 reduction at low temperatures. Our study demonstrates direct experimental evidence for the transient formation and high reactivity of proximately paired CuI sites under zeolite confinement and provides new insights into the monomeric-to-dimeric Cu transformation for completing the Cu redox cycle in low-temperature NH3-SCR catalysis over Cu-SSZ-13.
Collapse
Affiliation(s)
- Huarong Lei
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, School of Environment and Energy, South China University of Technology, 510006 Guangzhou, China
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Dongdong Chen
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, School of Environment and Energy, South China University of Technology, 510006 Guangzhou, China
| | - Jia-Yue Yang
- Optics & Thermal Radiation Research Center, Shandong University, Qingdao 266237 China
| | - Abhishek Khetan
- Fuel Science Center, RWTH Aachen University, Schinkelstr. 8, 52074 Aachen, Germany
| | - Jiuxing Jiang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou 510275 China
| | - Baoxiang Peng
- Laboratory of Industrial Chemistry, Ruhr-University Bochum, Universitätsstr. 150, Bochum 44780 Germany
| | - Ulrich Simon
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
- Fuel Science Center, RWTH Aachen University, Schinkelstr. 8, 52074 Aachen, Germany
| | - Daiqi Ye
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, School of Environment and Energy, South China University of Technology, 510006 Guangzhou, China
| | - Peirong Chen
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, School of Environment and Energy, South China University of Technology, 510006 Guangzhou, China
| |
Collapse
|
15
|
Huang S, Wang Q, Shan Y, Shi X, Liu Z, He H. Effects of Si/Al Ratio on Passive NO x Adsorption Performance over Pd/Beta Zeolites. Molecules 2023; 28:molecules28083501. [PMID: 37110735 PMCID: PMC10145102 DOI: 10.3390/molecules28083501] [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: 03/21/2023] [Revised: 04/07/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
In the current article, the effect of Si/Al ratio on the NOx adsorption and storage capacity over Pd/Beta with 1 wt% Pd loading was investigated. The XRD, 27Al NMR and 29Si NMR measurements were used to determine the structure of Pd/Beta zeolites. XAFS, XPS, CO-DRIFT, TEM and H2-TPR were used to identify the Pd species. The results showed that the NOx adsorption and storage capacity on Pd/Beta zeolites gradually decreased with the increase of Si/Al ratio. Pd/Beta-Si (Si-rich, Si/Al~260) rarely has NOx adsorption and storage capacity, while Pd/Beta-Al (Al-rich, Si/Al~6) and Pd/Beta-C (Common, Si/Al~25) exhibit excellent NOx adsorption and storage capacity and suitable desorption temperature. Pd/Beta-C has slightly lower desorption temperature compared to Pd/Beta-Al. The NOx adsorption and storage capacity increased for Pd/Beta-Al and Pd/Beta-C by hydrothermal aging treatment, while the NOx adsorption and storage capacity on Pd/Beta-Si had no change.
Collapse
Affiliation(s)
- Shasha Huang
- Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
- Engineering Research Center for Water Pollution Source Control & Eco-Remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Qiang Wang
- Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
- Engineering Research Center for Water Pollution Source Control & Eco-Remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Yulong Shan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoyan Shi
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhongqi Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| |
Collapse
|
16
|
Liu K, Li J, Yu Q, Han X, Bian M, Zhang Y, Yi T. Optimization and comprehensive mechanism of environment-friendly bimetal oxides catalysts for efficient removal of NO in ultra-low temperature flue gas. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2023.123324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
17
|
Fang Z, Zhang S, Wang A, Guo Y, Guo Y, Wang L, Zhan W. Er-modified MnO for selective catalytic reduction of NO with NH3 at low temperature: Promoting effect of erbium on catalytic performance. J RARE EARTH 2023. [DOI: 10.1016/j.jre.2023.01.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
18
|
Sun Y, Fu Y, Shan Y, Du J, Liu Z, Gao M, Shi X, He G, Xue S, Han X, Yu Y, He H. Si/Al Ratio Determines the SCR Performance of Cu-SSZ-13 Catalysts in the Presence of NO 2. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:17946-17954. [PMID: 36322164 DOI: 10.1021/acs.est.2c03813] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A comparative study was performed to investigate the NH3-selective catalytic reduction (SCR) reaction activity of Cu-SSZ-13 zeolites having Si/Al ratios (SARs) of 5, 18, and 30. Remarkably, the Cu-SSZ-13 zeolite catalysts exhibited completely opposite behaviors as a function of SAR under standard SCR (SSCR) and fast SCR (FSCR) reaction atmospheres. Under SSCR conditions, the NOx conversion increased as expected with the decreasing SAR. Under FSCR conditions, however, the NOx conversion decreased as the SAR decreased, contrary to expectations. In this study, based on characterization of the catalysts by X-ray diffraction, transmission electron microscopy, electron paramagnetic resonance, H2-temperature-programmed reduction, temperature-programmed desorption, and diffuse reflectance infrared Fourier transform spectroscopy, together with theoretical calculations, the authors found that the amount of Brønsted acid sites goes up while the SAR goes down, leading to an increase in the accumulation of NH4NO3 under FSCR reaction conditions. Moreover, the accumulated NH4NO3 is of greater stability for those low SAR Cu-SSZ-13 catalysts. These two reasons cause the FSCR performance of Cu-SSZ-13 to decrease with a decrease in SAR. As a result, the NO2 effect on SCR activity changes from promotion to inhibition as the SAR decreases.
Collapse
Affiliation(s)
- Yu Sun
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Yu Fu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Yulong Shan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
| | - Jinpeng Du
- Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen361021, China
| | - Zhongqi Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Meng Gao
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Xiaoyan Shi
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Guangzhi He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
| | - Sen Xue
- Weichai Power Co., Ltd., Weifang261061, China
| | - Xuewang Han
- Weichai Power Co., Ltd., Weifang261061, China
| | - Yunbo Yu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Sciences, Beijing100049, China
- Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen361021, China
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Sciences, Beijing100049, China
- Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen361021, China
| |
Collapse
|