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Zheng Y, Xiao H, Li K, Wang Y, Li Y, Wei Y, Zhu X, Li HW, Matsumura D, Guo B, He F, Chen X, Wang H. Ultra-Fine CeO 2 Particles Triggered Strong Interaction with LaFeO 3 Framework for Total and Preferential CO Oxidation. ACS APPLIED MATERIALS & INTERFACES 2020; 12:42274-42284. [PMID: 32830480 DOI: 10.1021/acsami.0c10271] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Interactions between the active components with the support are one of the fundamentally factors in determining the catalytic performance of a catalyst. In contrast to the comprehensive understanding on the strong metal-support interactions (SMSI) in metal-based catalysts, it remains unclear for the interactions among different oxides in mixed oxide catalysts due to its complexity. In this study, we investigated the interaction between CeO2 and LaFeO3, the two important oxygen storage materials in catalysis area, by tuning the sizes of CeO2 particles and highlight a two-fold effect of the strong oxide-oxide interaction in determining the catalytic activity and selectivity for preferential CO oxidation in hydrogen feeds. It is found that the anchoring of ultra-fine CeO2 particles (<2 nm) at the framework of three-dimensional-ordered macroporous LaFeO3 surface results in a strong interaction between the two oxides that induces the formation of abundant uncoordinated cations and oxygen vacancy at the interface, contributing to the improved oxygen mobility and catalytic activity for CO oxidation. Hydrogen spillover, which is an important evidence of the strong metal-support interactions in precious metal catalysts supported by reducible oxides, is also observed in the H2 reduction process of CeO2/LaFeO3 catalyst due to the presence of ultra-fine CeO2 particles (<2 nm). However, the strong interaction also results in the formation of surface hydroxyl groups, which when combined with the hydrogen spillover reduces the selectivity for preferential CO oxidation. This discovery demonstrates that in hybrid oxide-based catalysts, tuning the interaction among different components is essential for balancing the catalytic activity and selectivity.
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Affiliation(s)
- Yane Zheng
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Engineering, Kunming University of Science and Technology, Kunming 650093, China
- Faculty of chemical Engineering, Kunming University of Science and Technology, Kunming 650093, China
| | - Hang Xiao
- Department of Earth and Environmental Engineering, Columbia University, New York, New York 10027, United States
| | - Kongzhai Li
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China
- Department of Earth and Environmental Engineering, Columbia University, New York, New York 10027, United States
| | - Yuhao Wang
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Engineering, Kunming University of Science and Technology, Kunming 650093, China
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China
| | - Yongtao Li
- School of Materials Science and Engineering, Anhui University of Technology, Maanshan, 243002, China
- Platform of Inter/Transdisciplinary Energy Research, International Research Center for Hydrogen Energy, International Institute for Carbon-Neutral Energy Research, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan
| | - Yonggang Wei
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Engineering, Kunming University of Science and Technology, Kunming 650093, China
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China
| | - Xing Zhu
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Engineering, Kunming University of Science and Technology, Kunming 650093, China
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China
| | - Hai-Wen Li
- Platform of Inter/Transdisciplinary Energy Research, International Research Center for Hydrogen Energy, International Institute for Carbon-Neutral Energy Research, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan
| | - Daiju Matsumura
- Quantum Beam Science Directorate, Japan Atomic Energy Agency, SPring-8, 1-1-1 Koto, Sayo, Hyogo 679-5148, Japan
| | - Binglin Guo
- Platform of Inter/Transdisciplinary Energy Research, International Research Center for Hydrogen Energy, International Institute for Carbon-Neutral Energy Research, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan
| | - Fang He
- College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541006, PR China
| | - Xi Chen
- Department of Earth and Environmental Engineering, Columbia University, New York, New York 10027, United States
| | - Hua Wang
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Engineering, Kunming University of Science and Technology, Kunming 650093, China
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Chubar N, Gilmour R, Gerda V, Mičušík M, Omastova M, Heister K, Man P, Fraissard J, Zaitsev V. Layered double hydroxides as the next generation inorganic anion exchangers: Synthetic methods versus applicability. Adv Colloid Interface Sci 2017; 245:62-80. [PMID: 28477867 DOI: 10.1016/j.cis.2017.04.013] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 04/21/2017] [Accepted: 04/24/2017] [Indexed: 10/19/2022]
Abstract
This work is the first report that critically reviews the properties of layered double hydroxides (LDHs) on the level of speciation in the context of water treatment application and dynamic adsorption conditions, as well as the first report to associate these properties with the synthetic methods used for LDH preparation. Increasingly stronger maximum allowable concentrations (MAC) of various contaminants in drinking water and liquid foodstuffs require regular upgrades of purification technologies, which might also be useful in the extraction of valuable substances for reuse in accordance with modern sustainability strategies. Adsorption is the main separation technology that allows the selective extraction of target substances from multicomponent solutions. Inorganic anion exchangers arrived in the water business relatively recently to achieve the newly approved standards for arsenic levels in drinking water. LDHs (or hydrotalcites, HTs) are theoretically the best anion exchangers due to their potential to host anions in their interlayer space, which increases their anion removal capacity considerably. This potential of the interlayer space to host additional amounts of target aqueous anions makes the LDHs superior to bulk anion exchanger. The other unique advantage of these layered materials is the flexibility of the chemical composition of the metal oxide-based layers and the interlayer anions. However, until now, this group of "classical" anion exchangers has not found its industrial application in adsorption and catalysis at the industrial scale. To accelerate application of LDHs in water treatment on the industrial scale, the authors critically reviewed recent scientific and technological knowledge on the properties and adsorptive removal of LDHs from water on the fundamental science level. This also includes review of the research tools useful to reveal the adsorption mechanism and the material properties beyond the nanoscale. Further, these properties are considered in association with the synthetic methods by which the LDHs were produced. Special attention is paid to the LDH properties that are particularly relevant to water treatment, such as exchangeability ease of the interlayer anions and the LDH stability at the solid-water interface. Notably, the LDH properties (e.g., rich speciation, hydration, and the exchangeability ease of the interlayer anions with aqueous anions) are considered in the synthetic strategy context applied to the material preparation. One such promising synthetic method has been developed by the authors who supported their opinions by the unpublished data in addition to reviewing the literature. The reviewing approach allowed for establishing regularities between the parameters: the LDH synthetic method-structure/surface/interlayer-removal-suitability for water treatment. Specifically, this approach allowed for a conclusion about either the unsuitability or promising potential of some synthetic methods (or the removal approaches) used for the preparation of LDHs for water purification at larger scales. The overall reviewing approach undertaken by the authors in this work mainly complements the other reviews on LDHs (published over the past seven to eight years) and for the first time compares the properties of these materials beyond the nanoscale.
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