Cu-exchanged Al-rich OFF-CHA twin-crystal zeolite for the selective catalytic reduction of NOx by NH3

Han, Jinfeng; Liu, Caixia; Liu, Qingling; Lu, Shuangchun; Bi, Yalian; Wang, Xiaohan; Guo, Mingyu; Song, Chunfeng; Ji, Na; Lü, Xuebin; Ma, Degang; Li, Zhenguo

doi:10.1016/j.cattod.2020.07.082

Cited by 11 publications

(9 citation statements)

References 46 publications

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“…(b) NOx conversion of Cu 3.1 -OFF/CHA before and after hydrothermal treatment at 750 °C for 16 h. (c) Assessment of SO 2 +H 2 O resistance on Cu 3.1 -OFF-CHA catalysts. Reproduced with permission from ref . Copyright 2021 Elsevier.…”

Section: Catalysis Of Intergrowth Zeolitementioning

confidence: 99%

Intergrowth Zeolites, Synthesis, Characterization, and Catalysis

Wang,

Tong,

Liu

et al. 2023

Chem. Rev.

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Microporous zeolites that can act as heterogeneous catalysts have continued to attract a great deal of academic and industrial interest, but current progress in their synthesis and application is restricted to single-phase zeolites, severely underestimating the potential of intergrowth frameworks. Compared with single-phase zeolites, intergrowth zeolites possess unique properties, such as different diffusion pathways and molecular confinement, or special crystalline pore environments for binding metal active sites. This review first focuses on the structural features and synthetic details of all the intergrowth zeolites, especially providing some insightful discussion of several potential frameworks. Subsequently, characterization methods for intergrowth zeolites are introduced, and highlighting fundamental features of these crystals. Then, the applications of intergrowth zeolites in several of the most active areas of catalysis are presented, including selective catalytic reduction of NOx by ammonia (NH 3 -SCR), methanol to olefins (MTO), petrochemicals and refining, fine chemicals production, and biomass conversion on Beta, and the relationship between structure and catalytic activity was profiled from the perspective of intergrowth grain boundary structure. Finally, the synthesis, characterization, and catalysis of intergrowth zeolites are summarized in a comprehensive discussion, and a brief outlook on the current challenges and future directions of intergrowth zeolites is indicated.

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Section: Catalysis Of Intergrowth Zeolitementioning

confidence: 99%

Intergrowth Zeolites, Synthesis, Characterization, and Catalysis

Wang,

Tong,

Liu

et al. 2023

Chem. Rev.

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“…Cu-zeolites with a combination of two zeolite structures showed enhanced HTA stability over single catalyst. For example, Cu-ZST-1 (AFX/CHA), 15 Cu-SAPO-34/5 (CHA/AFI), 16 and Cu-OFF/CHA 17 composites exhibited improved hydrothermal stability than the individual component. Our previous work also showed that the mixed Cu-SSZ-13/Cu-SAPO-34 composites performed a much better HTA stability than Cu-SSZ-13, due to the intense interaction between the two components (SSZ-13 and SAPO-34) during HTA.…”

Section: Introductionmentioning

confidence: 99%

Effect of hydrothermal aging temperature on a Cu-SSZ-13/H-SAPO-34 composite for the selective catalytic reduction of NO_xby NH₃

et al. 2021

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“…Zeolites have mordenite framework inverted structures and chabazite (CHA) framework structures. , The Cu-SSZ-13 catalyst is a class of Cu-CHA with smaller pore structures, and it has good hydrothermal stability for the urea-SCR reaction . The NOx conversion rate of Cu-CHA catalysts is over 90% in the range of 160–550 °C . Ammonia is the reducing agent in SCR reactions, and it is stored in the form of 32.5% urea aqueous solution .…”

Section: Introductionmentioning

confidence: 99%

“…9 The NOx conversion rate of Cu-CHA catalysts is over 90% in the range of 160−550 °C. 10 Ammonia is the reducing agent in SCR reactions, and it is stored in the form of 32.5% urea aqueous solution. 6 The SCR system consists of 20 potential reactions, which can be simplified as three main SCR reactions.…”

Section: Introductionmentioning

confidence: 99%

“…Cu-SAPO-34 with a high Si content and a medium Cu content showed the lowest oxidation activities. Han et al 10 synthesized a novel Al-rich OFF-CHA twin-crystal zeolite. The reason of the superior characteristics of Cu-OFF-CHA was that Cu 2+ in the OFF sites on Cu-OFF-CHA was more stable, resulting in less conversion of the active site to CuOx clusters.…”

Section: Introductionmentioning

confidence: 99%

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Effects of Catalyst Physicochemical Properties on the Catalytic Activity of Cu Zeolite Selective Catalytic Reduction at Different Inlet Gas Conditions

Tan

Yin

et al. 2021

Energy Fuels

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Selective catalytic reduction (SCR) systems are important technical means of mitigating NOx emissions for diesel engines. The major challenge of this technique is to improve the low-temperature activity of the catalyst during engine cold start and the thermal stability on repeated exposure to high-temperature exhaust. A two-stage SCR system with a Cu-SSZ-13 catalyst was analyzed with SCR sample experiments and NH3 oxidation experiments. The effects of copper content, doping metals, structural arrangement, NO2/NOx ratio, and NH3/NOx ratio (ANR) on the NOx conversion reaction at different temperatures were investigated. Furthermore, the Cu-SSZ-13 catalyst activity was characterized by Fourier transform infrared spectroscopy, H2 temperature-programmed reduction, and X-ray diffraction. The results showed that the low-temperature catalytic performance first increased with increasing copper content and decreased with a further increase. The optimal value of copper content was around 3.4%. The thermal stability of Cu-SSZ-13 catalysts decreased with the increase in the copper content. The temperature window of the high NOx conversion rate was widened by doping Zr/Mn/Ce, and the temperature window was widened by 15.1–33.1%. The two-stage SCR system was compared with a single SCR, which showed that the NH3 oxidation rate increased by 46.9–88.7%, the NOx conversion rate increased by 67.7–85.5%, and T90 was optimized by 3.3–13.5% during engine cold start. This made the total NOx conversion rate to maintain a high level above 80% at temperatures over 500 °C. An appropriate NO2/NOx ratio and ANR could improve the NOx conversion rate at a low-temperature range.

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Cu-exchanged Al-rich OFF-CHA twin-crystal zeolite for the selective catalytic reduction of NOx by NH3

Cited by 11 publications

References 46 publications

Intergrowth Zeolites, Synthesis, Characterization, and Catalysis

Intergrowth Zeolites, Synthesis, Characterization, and Catalysis

Effect of hydrothermal aging temperature on a Cu-SSZ-13/H-SAPO-34 composite for the selective catalytic reduction of NO_xby NH₃

Effects of Catalyst Physicochemical Properties on the Catalytic Activity of Cu Zeolite Selective Catalytic Reduction at Different Inlet Gas Conditions

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Cu-exchanged Al-rich OFF-CHA twin-crystal zeolite for the selective catalytic reduction of NOx by NH3

Cited by 11 publications

References 46 publications

Intergrowth Zeolites, Synthesis, Characterization, and Catalysis

Intergrowth Zeolites, Synthesis, Characterization, and Catalysis

Effect of hydrothermal aging temperature on a Cu-SSZ-13/H-SAPO-34 composite for the selective catalytic reduction of NOxby NH3

Effects of Catalyst Physicochemical Properties on the Catalytic Activity of Cu Zeolite Selective Catalytic Reduction at Different Inlet Gas Conditions

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Effect of hydrothermal aging temperature on a Cu-SSZ-13/H-SAPO-34 composite for the selective catalytic reduction of NO_xby NH₃