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Yoko A, Wang H, Furuya K, Takahashi D, Seong G, Tomai T, Frenkel AI, Saito M, Inoue K, Ikuhara Y, Adschiri T. Reduction of (100)-Faceted CeO 2 for Effective Pt Loading. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2024; 36:5611-5620. [PMID: 38883434 PMCID: PMC11171262 DOI: 10.1021/acs.chemmater.4c00627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/03/2024] [Accepted: 05/06/2024] [Indexed: 06/18/2024]
Abstract
Although the function and stability of catalysts are known to significantly depend on their dispersion state and support interactions, the mechanism of catalyst loading has not yet been elucidated. To address this gap in knowledge, this study elucidates the mechanism of Pt loading based on a detailed investigation of the interaction between Pt species and localized polarons (Ce3+) associated with oxygen vacancies on CeO2(100) facets. Furthermore, an effective Pt loading method was proposed for achieving high catalytic activity while maintaining the stability. Enhanced dispersibility and stability of Pt were achieved by controlling the ionic interactions between dissolved Pt species and CeO2 surface charges via pH adjustment and reduction pretreatment of the CeO2 support surface. This process resulted in strong interactions between Pt and the CeO2 support. Consequently, the oxygen-carrier performance was improved for CH4 chemical looping reforming reactions. This simple interaction-based loading process enhanced the catalytic performance, allowing the efficient use of noble metals with high performance and small loading amounts.
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Affiliation(s)
- Akira Yoko
- WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- International Center for Synchrotron Radiation Innovation Smart (SRIS), Tohoku University, 468-1, Aoba, Aramaki, Aoba-ku, Sendai 980-8572, Japan
| | - Haodong Wang
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Ko Furuya
- Department of Chemical Engineering, Graduate School of Engineering, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Daiki Takahashi
- Department of Chemical Engineering, Graduate School of Engineering, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Gimyeong Seong
- Department of Environmental & Energy Engineering, The University of Suwon, 17 Wauan-gil, Bongdam-eup, Hwaseong-si 18323, Gyeonggi-do, Republic of Korea
| | - Takaaki Tomai
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Anatoly I Frenkel
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Mitsuhiro Saito
- Institute of Engineering Innovation, The University of Tokyo, Tokyo 113-8656, Japan
| | - Kazutoshi Inoue
- WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Yuichi Ikuhara
- WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Institute of Engineering Innovation, The University of Tokyo, Tokyo 113-8656, Japan
| | - Tadafumi Adschiri
- WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- New Industry Creation Hatchery Center, Tohoku University, Sendai 980-8579, Japan
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Zhang Y, Yu S, Huang X, Qin Z, Liu T, Tang G, Xie X. Preparation of porous superabsorbent particles based on starch by supercritical CO 2 drying and its water absorption mechanism. Int J Biol Macromol 2024; 258:129102. [PMID: 38163499 DOI: 10.1016/j.ijbiomac.2023.129102] [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: 10/27/2023] [Revised: 12/09/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024]
Abstract
The slow water-absorption speed of starch-based superabsorbent resin (St-SAP) limits its application. In this study, porous St-SAP (P-St-SAP) was prepared by inverse suspension polymerization and supercritical CO2 drying, the aim is to provide a preparation method of fast absorbent resin. The P-St-SAP at 33 % starch content had an interpenetrating porous structure with macropores, mesopores and micropores, and the surface area, pore volume and average pore diameter were 32.06 m2·g-1, 0.116 cm3·g-1 and 21.6 nm, respectively. The water-absorption process included rapid-section, medium-section and slow-section, according with internal diffusion, double-constant and quasi second-order kinetic models, respectively. In the initial 30 s, a water-absorption speed of 262.6 g·g-1·min-1 in distilled water was much higher than some previous research results, and the equilibrium absorption value of 517.9 g·g-1 in distilled water and 72.9 g·g-1 in 0.9 % saline was better than that of non-porous St-SAP at similar starch content. Moreover, at the same stage the percentage of saline absorption ratio to equilibrium absorption value was 1.0- 2.0 times higher than that of distilled water. These research results indicate that the P-St-SAP has fast water-absorption speed and good salt resistance, which will have greater application prospects in sanitary materials, building concrete pouring, and flood control blocking piping.
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Affiliation(s)
- Youquan Zhang
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Shenghua Yu
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Xinyi Huang
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Zuzeng Qin
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Tusong Liu
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China; Guangxi Shengya Technology Group Co., Ltd, Liuzhou 545600, China
| | - Guo Tang
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Xinling Xie
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China.
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Synthesis of Micro- and Nanoparticles in Sub- and Supercritical Water: From the Laboratory to Larger Scales. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10165508] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The use of micro- and nanoparticles is gaining more and more importance because of their wide range of uses and benefits based on their unique mechanical, physical, electrical, optical, electronic, and magnetic properties. In recent decades, supercritical fluid technologies have strongly emerged as an effective alternative to other numerous particle generation processes, mainly thanks to the peculiar properties exhibited by supercritical fluids. Carbon dioxide and water have so far been two of the most commonly used fluids for particle generation, the former being the fluid par excellence in this field, mainly, because it offers the possibility of precipitating thermolabile particles. Nevertheless, the use of high-pressure and -temperature water opens an innovative and very interesting field of study, especially with regards to the precipitation of particles that could hardly be precipitated when CO2 is used, such as metal particles with a considerable value in the market. This review describes an innovative method to obtain micro- and nanoparticles: hydrothermal synthesis by means of near and supercritical water. It also describes the differences between this method and other conventional procedures, the most currently active research centers, the types of particles synthesized, the techniques to evaluate the products obtained, the main operating parameters, the types of reactors, and amongst them, the most significant and the most frequently used, the scaling-up studies under progress, and the milestones to be reached in the coming years.
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