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Kimura T. Utilization of Reactive Nitrogen Compounds for Nitrogen Circular Economy. CHEM REC 2024; 24:e202400094. [PMID: 39092686 DOI: 10.1002/tcr.202400094] [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: 05/15/2024] [Indexed: 08/04/2024]
Abstract
Nitrogen oxides (NOx) should be purified according to environmental regulations, being restricted increasingly year by year. A wide variety of denitration technologies, such as selective catalytic reduction (SCR) of NOx to nitrogen (N2) and NOx storage reduction (NSR) to N2 by injecting reducing agents like ammonia (NH3), has so far been developed practically. Sophisticated catalytic approaches are perhaps mandatory for the sustainability in energy including complete purification of NOx. As one of the solutions to overcome problems for environment and resource simultaneously, this concept article focuses on the utilization of reactive nitrogen (Nr) compounds, mainly NOx, for encouraging an opening to consider nitrogen circular economy. For the recycling of NOx via NH3, a challenging but rational catalytic technology can be proposed by an alternate switching the inlet gas between NOx containing oxidative gas and H2 containing reductive one without an operation to change the reaction temperature. Considering the reactivity of NOx higher than that of N2, this kind of NOx to NH3 (NTA) process is promising for synthesizing NH3, being valuable not only as fertilizer but also as fuel in near future.
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Affiliation(s)
- Tatsuo Kimura
- National Institute of Advanced Industrial Science and Technology (AIST), Sakurazaka, Moriyama-ku, Nagoya, 463-8560, Japan
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2
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Kimura T. Smart synthesis of highly porous metal oxide powders with the self-assembly of amphiphilic organic compounds. Dalton Trans 2024; 53:12434-12441. [PMID: 38922321 DOI: 10.1039/d4dt01427h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
Supramolecular chemistry-mediated synthesis has thus far been employed for the design of ordered mesoporous structures surrounded by various metal oxides that are helpful as nanometer-scaled unique reaction containers with high specific surface area, large pore volume and uniform mesopores useful for the storage and mass transport of large-sized molecules. The evaporation-induced self-assembly (EISA) process is very powerful for fabricating mesoporous metal oxide films with the rapid evaporation of solvents. Although a similar EISA process is also applied to synthesize mesoporous metal oxide powders using the room-temperature drying process with slow evaporation of solvents, the control of the evaporation rate should be quantified for the complete reproduction of high-quality metal oxide powders. In this feature article, I introduce our recent challenge in synthesizing highly porous metal oxides in powder form with the smart optimization of synthetic conditions by combining several EISA processes to eliminate the mismatch of the rate of solvent evaporation, inducing the self-assembly of amphiphilic organic molecules.
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Affiliation(s)
- Tatsuo Kimura
- National Institute of Advanced Industrial Science and Technology (AIST), Sakurazaka, Moriyama-ku, Nagoya 463-8560, Japan.
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Kimura T. Efficient optimization of the synthetic conditions for aerosol-assisted high-quality mesoporous CeO 2 powders. RSC Adv 2024; 14:16704-16712. [PMID: 38784420 PMCID: PMC11110799 DOI: 10.1039/d4ra01674b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
The morphology of surfactant-assisted mesoporous metal oxides was tuned to obtain high surface-area particles by utilizing the synthetic conditions for fabricating transparent thin films through an evaporation-induced self-assembly (EISA) process. For investigating their potential applications, especially for designing heterogeneous catalysts, mesoporous metal oxides should be obtained in powder forms; however, a serious limitation associated with their reproducibility persists. Herein, along with a rapid optimization approach, starting from determining and improving chemical composition for the fabrication of mesoporous metal oxide films, an advanced approach to obtain highly porous metal oxide powders is presented using a temperature-controlled spray-drying process with step-by-step but smooth optimization by combining several EISA processes, involving the utilization of a precursor solution optimized for a slow-drying process in the case of ceria (CeO2) using poly(styrene)-block-poly(ethylene oxide) (PS-b-PEO).
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Affiliation(s)
- Tatsuo Kimura
- National Institute of Advanced Industrial Science and Technology (AIST) Sakurazaka, Moriyama-ku Nagoya 463-8560 Japan
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Li X, Li W, Zhang J, Yin W, Xia Y, Xie K. Porous Single-crystalline Centimeter-sized α-Al 2 O 3 Monoliths for Selective and Durable Non-oxidative Dehydrogenation of Ethane. Angew Chem Int Ed Engl 2024; 63:e202315274. [PMID: 38050771 DOI: 10.1002/anie.202315274] [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: 10/10/2023] [Revised: 12/02/2023] [Accepted: 12/04/2023] [Indexed: 12/06/2023]
Abstract
Alpha alumina (α-Al2 O3 ) are inert materials with outstanding thermal, chemical and mechanical stability. Herein, we fabricate porous single-crystalline (PSC) α-Al2 O3 monoliths at centimeter scale to endow them with high catalytic activity while maintaining their stability. We reduce PSC α-Al2 O3 monoliths to create oxygen vacancies in lattice and stabilize them by the ordered lattice to construct unsaturated Al-O coordination structures for enhancing the catalytic activity. The generation of oxygen vacancy at 18e wyckoff position contributes to the unsaturated Al-O coordination. As a case study, we demonstrate the outstanding performance with conversion (≈34 %) and selectivity (≈95 %) toward non-oxidative dehydrogenation of ethane to ethylene at 700 °C. We achieve the outstanding performance without obvious degradation even after a continuous operation over 1000 hours at 700 °C.
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Affiliation(s)
- Xue Li
- Key Laboratory of Design & Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, Fujian, 350108, China
- Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
| | - Wenting Li
- Key Laboratory of Design & Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, Fujian, 350108, China
- Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
| | - Jie Zhang
- Key Laboratory of Design & Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, Fujian, 350108, China
- Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
| | - Wen Yin
- Spallation Neutron Source Science Center, Dongguan, Guangdong, 523803, China
| | - Yuanguang Xia
- Spallation Neutron Source Science Center, Dongguan, Guangdong, 523803, China
| | - Kui Xie
- Key Laboratory of Design & Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, Fujian, 350108, China
- Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
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Zhang Y, Wakabayashi R, Kimura T. Aerosol-assisted synthesis of titania-based spherical and fibrous materials with a rational design of mesopores using PS- b-PEO. Dalton Trans 2023; 52:1543-1550. [PMID: 36533632 DOI: 10.1039/d2dt03402f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Surfactant-assisted synthesis is a promising technique for the tailor-made design of highly porous metal oxide based nanomaterials. There has been a demand for the comprehensive design of their morphology, porous structure and crystallinity to extend potential applications using metal oxide based materials such as titania (TiO2). However, the porous structure is often deformed and/or destroyed during the process of crystallizing metal oxide frameworks. Herein, the aerosol-assisted synthesis of mesoporous TiO2 powders was conducted in the presence of high-molecular-weight poly(styrene)-block-poly(ethylene oxide) (PS-b-PEO), which improved the stability of the derivative mesoporous structure with an increase in the thickness of the TiO2 frameworks. To propose a rational synthetic route for stable and porous metal oxides, the resultant mesoporous structure and the textural morphology of the mesoporous TiO2 powders were surveyed using PS-b-PEO with different lengths of PS and PEO chains. By a judicious choice of the molecular structure of PS-b-PEO, the morphological design of the fully crystallized anatase phase of TiO2 from spherical to fibrous ones was achieved with control over the mesopore diameter.
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Affiliation(s)
- Yuxiao Zhang
- Innovative Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Sakurazaka, Moriyama-ku, Nagoya 463-8560, Japan.
| | - Ryutaro Wakabayashi
- Innovative Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Sakurazaka, Moriyama-ku, Nagoya 463-8560, Japan.
| | - Tatsuo Kimura
- Innovative Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Sakurazaka, Moriyama-ku, Nagoya 463-8560, Japan.
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Islam MS, Wakabayashi R, Kimura T. Enhanced γ-phase crystallinity of Al 2O 3 frameworks at the concave surface of PS- b-PEO templated spherical pores. Dalton Trans 2021; 50:7191-7197. [PMID: 33871514 DOI: 10.1039/d1dt00719j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The crystallinity of inorganic solids like metal oxides after the porosity design is the crucial factor that should be investigated for enhancing their physicochemical properties. In most cases, metal oxide frameworks around mesopores, that are designed through the supramolecular mediated approach, are resulted to be amorphous. Accordingly, a rational guideline has been required for enhancing the crystallinity of frameworks at such concave surfaces. We have so far surveyed a crystallization behavior of alumina (Al2O3) frameworks to its γ-phase around spherical mesopores (∼40 nm) and discussed further transition to the α-phase around much larger pores (∼200 nm). In this paper, we prepared new and helpful Al2O3 powders having PS-b-PEO templated pores (∼25 nm and ∼75 nm) smaller than those of our previous case. After careful discussion of the pore size variation by considering the molecular structure of PS-b-PEO, we explained the crystallization behavior of the Al2O3 frameworks to enhance its γ-crystallinity. This knowledge is quite beneficial for designing highly porous Al2O3 powders with abundant crystallinity for use as catalyst supports, which is very useful for assessing synthetic procedures of other mesoporous metal oxides having high crystallinity.
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Affiliation(s)
- Md Saidul Islam
- Innovative Functional Material Research institute, National Institute of Advanced Industrial Science and Technology (AIST), Shimoshidami, Moriyama-ku, Nagoya 463-8560, Japan.
| | - Ryutaro Wakabayashi
- Innovative Functional Material Research institute, National Institute of Advanced Industrial Science and Technology (AIST), Shimoshidami, Moriyama-ku, Nagoya 463-8560, Japan.
| | - Tatsuo Kimura
- Innovative Functional Material Research institute, National Institute of Advanced Industrial Science and Technology (AIST), Shimoshidami, Moriyama-ku, Nagoya 463-8560, Japan.
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Murata K, Shiotani T, Ohyama J, Wakabayashi R, Maruoka H, Kimura T, Satsuma A. Relationship between penta-coordinated Al 3+ sites in the Al 2O 3 supports and CH 4 combustion activity of Pd/Al 2O 3 catalysts. Catal Sci Technol 2021. [DOI: 10.1039/d1cy00098e] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Pd/Al2O3 catalysts were prepared using various Al2O3 supports with different structural features, revealing a significant insight into the methane (CH4) combustion activity of Pd nanoparticles with the fraction of penta-coordinated Al3+ sites in the Al2O3 supports.
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Affiliation(s)
- Kazumasa Murata
- Graduate School of Engineering
- Nagoya University
- Nagoya 464-8603
- Japan
| | - Takumi Shiotani
- Graduate School of Engineering
- Nagoya University
- Nagoya 464-8603
- Japan
| | - Junya Ohyama
- Faculty of Advanced Science and Technology
- Kumamoto University
- Kumamoto 860-8555
- Japan
- Elements Strategy Initiative for Catalysts and Batteries (ESICB)
| | - Ryutaro Wakabayashi
- National Institute of Advanced Industrial Science and Technology (AIST)
- Moriyama-ku
- Japan
| | - Hirokazu Maruoka
- National Institute of Advanced Industrial Science and Technology (AIST)
- Moriyama-ku
- Japan
| | - Tatsuo Kimura
- National Institute of Advanced Industrial Science and Technology (AIST)
- Moriyama-ku
- Japan
| | - Atsushi Satsuma
- Graduate School of Engineering
- Nagoya University
- Nagoya 464-8603
- Japan
- Elements Strategy Initiative for Catalysts and Batteries (ESICB)
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Wakabayashi R. Accelerated crystallization of mesoporous Al 2O 3 powder recovered by spray-drying with a large amount of heated air. NEW J CHEM 2021. [DOI: 10.1039/d1nj01488a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Crystallization into α-Al2O3 was accelerated with a large amount of heated air during spray-drying to recover mesoporous Al2O3 powders.
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Affiliation(s)
- Ryutaro Wakabayashi
- Innovative Functional Materials Research Institute
- National Institute of Advanced Industrial Science and Technology (AIST)
- Shimoshidami
- Moriyama-ku
- Nagoya 463-8560
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Wakabayashi R, Tomita A, Kimura T. Understanding of NOx storage property of impregnated Ba species after crystallization of mesoporous alumina powders. JOURNAL OF HAZARDOUS MATERIALS 2020; 398:122791. [PMID: 32768855 DOI: 10.1016/j.jhazmat.2020.122791] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 04/17/2020] [Accepted: 04/19/2020] [Indexed: 06/11/2023]
Abstract
The regulation of automobile exhaust gas, especially that concerning hazardous nitrogen oxide (called as NOx) becomes stricter year-by-year, which should be urgently corresponded for cleaning the NOx containing emission. According to surface affinity of γ-alumina to metal catalysts and its thermal stability, crystalline γ-alumina has been frequently utilized as catalyst supports showing relatively high specific surface area. From the viewpoint, we consider that highly porous alumina powders prepared using amphiphilic organic molecules are potential as such a catalyst support for improving NOx removing property. In this study, we report surface property of the mesoporous alumina powders against NOx molecules after crystallizing to its γ-phase and NOx storage property after impregnation of barium (Ba) acetate in the mesopores. Adsorption of NO with O2 on mesoporous γ-alumina powders without Ba species were more likely to be bridging bidentate than chelating bidentate nitrates (NO3-) with comparing to commercially available γ-alumina powders. After impregnating the Ba species, admitted NO molecules were oxidized with enough O2 and stored very strongly as ionic nitrate (NO3-) onto the Ba species even after heating at 500 °C. This preliminary study is helpful for designing mesoporous deNOx catalysts combined with unique storage/adsorption property.
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Affiliation(s)
- Ryutaro Wakabayashi
- Innovative Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Shimoshidami, Moriyama-ku, Nagoya, 463-8560, Japan
| | - Atsuko Tomita
- Innovative Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Shimoshidami, Moriyama-ku, Nagoya, 463-8560, Japan
| | - Tatsuo Kimura
- Innovative Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Shimoshidami, Moriyama-ku, Nagoya, 463-8560, Japan.
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10
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Maruoka H, Kimura T. An Effective Strategy to Obtain Highly Porous Alumina Powders Having Robust and Designable Extra-Large Pores. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2019. [DOI: 10.1246/bcsj.20190222] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Hirokazu Maruoka
- Inorganic Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Shimoshidami, Moriyama-ku, Nagoya, Aichi 463-8560, Japan
| | - Tatsuo Kimura
- Inorganic Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Shimoshidami, Moriyama-ku, Nagoya, Aichi 463-8560, Japan
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