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Jiao Y, Xu K, Xiao H, Mei C, Li J. Biomass-Derived Carbon Aerogels for ORR/OER Bifunctional Oxygen Electrodes. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2397. [PMID: 37686905 PMCID: PMC10490280 DOI: 10.3390/nano13172397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/13/2023] [Accepted: 08/16/2023] [Indexed: 09/10/2023]
Abstract
The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial electrochemical reactions that play vital roles in energy conversion and storage technologies, such as fuel cells and metal-air batteries. Typically, noble-metal-based catalysts are required to enhance the sluggish kinetics of the ORR and OER, but their high costs restrict their practical commercial applications. Thus, highly active and strong non-noble metal catalysts are essential to address the cost and durability challenge. Based on previous research, carbon-based catalysts may present the best alternatives to these precious metals in the future owing to their affordability, very large surface areas, and superior mechanical and electrical qualities. In particular, carbon aerogels prepared using biomass as the precursors are referred to as biomass-derived carbon aerogels. They have sparked broad attention and demonstrated remarkable performance in the energy conversion and storage sectors as they are ecologically beneficial, affordable, and have an abundance of precursors. Therefore, this review focuses on various nanostructured materials based on biomass-derived carbon aerogels as ORR/OER catalysts, including metal atoms, metal compounds, and alloys.
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Affiliation(s)
- Yue Jiao
- Co-Innovation Center of Efficient Processing and Utilization of Forest Resources—International Innovation Center for Forest Chemicals and Materials, Joint International Research Laboratory of Lignocellulosic Functional Materials, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China; (K.X.); (C.M.)
| | - Ke Xu
- Co-Innovation Center of Efficient Processing and Utilization of Forest Resources—International Innovation Center for Forest Chemicals and Materials, Joint International Research Laboratory of Lignocellulosic Functional Materials, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China; (K.X.); (C.M.)
| | - Huining Xiao
- Chemical Engineering Department, New Brunswick University, Fredericton, NB E3B 5A3, Canada;
| | - Changtong Mei
- Co-Innovation Center of Efficient Processing and Utilization of Forest Resources—International Innovation Center for Forest Chemicals and Materials, Joint International Research Laboratory of Lignocellulosic Functional Materials, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China; (K.X.); (C.M.)
| | - Jian Li
- Material Science and Engineering College, Northeast Forestry University, Harbin 150040, China
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Arzani FA, Dos Santos JHZ. Biocides and techniques for their encapsulation: a review. SOFT MATTER 2022; 18:5340-5358. [PMID: 35820409 DOI: 10.1039/d1sm01114f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Biocides are compounds that are broadly used to protect products and equipment against microbiological damage. Encapsulation can effectively increase physicochemical stability and allow for controlled release of encapsulated biocides. We categorized microencapsulation into coacervation, sol-gel, and self-assembly methods. The former comprises internal phase separation, interfacial polymerization, and multiple emulsions, and the latter include polymersomes and layer-by-layer techniques. The focus of this review is the description of these categories based on their microencapsulation methods and mechanisms. We discuss the key features and potential applications of each method according to the characteristics of the biocide to be encapsulated, relating the solubility of biocides to the capsule-forming materials, the reactivity between them and the desired release rate. The role of encapsulation in the safety and toxicity of biocide applications is also discussed. Furthermore, future perspectives for biocide applications and encapsulation techniques are presented.
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Affiliation(s)
- Fernanda A Arzani
- Chemical Engineering Department, Universidade Federal do Rio Grande do Sul, Rua Eng. Luiz Englert s/n, Porto Alegre, 90040-040, Brazil.
| | - João H Z Dos Santos
- Institute of Chemistry, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, Porto Alegre, 91500-000, Brazil.
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Smeets V, Gaigneaux EM, Debecker DP. Titanosilicate Epoxidation Catalysts: A Review of Challenges and Opportunities. ChemCatChem 2022. [DOI: 10.1002/cctc.202101132] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Valentin Smeets
- Institute of Condensed Matter and Nanosciences (IMCN) Université catholique de Louvain (UCLouvain) Place Louis Pasteur 1, Box L4.01.09 1348 Louvain-la-Neuve Belgium
| | - Eric M. Gaigneaux
- Institute of Condensed Matter and Nanosciences (IMCN) Université catholique de Louvain (UCLouvain) Place Louis Pasteur 1, Box L4.01.09 1348 Louvain-la-Neuve Belgium
| | - Damien P. Debecker
- Institute of Condensed Matter and Nanosciences (IMCN) Université catholique de Louvain (UCLouvain) Place Louis Pasteur 1, Box L4.01.09 1348 Louvain-la-Neuve Belgium
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Alekseev ES, Alentiev AY, Belova AS, Bogdan VI, Bogdan TV, Bystrova AV, Gafarova ER, Golubeva EN, Grebenik EA, Gromov OI, Davankov VA, Zlotin SG, Kiselev MG, Koklin AE, Kononevich YN, Lazhko AE, Lunin VV, Lyubimov SE, Martyanov ON, Mishanin II, Muzafarov AM, Nesterov NS, Nikolaev AY, Oparin RD, Parenago OO, Parenago OP, Pokusaeva YA, Ronova IA, Solovieva AB, Temnikov MN, Timashev PS, Turova OV, Filatova EV, Philippov AA, Chibiryaev AM, Shalygin AS. Supercritical fluids in chemistry. RUSSIAN CHEMICAL REVIEWS 2020. [DOI: 10.1070/rcr4932] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Zhou C, Shi J, Zhou W, Cheng K, Zhang Q, Kang J, Wang Y. Highly Active ZnO-ZrO2 Aerogels Integrated with H-ZSM-5 for Aromatics Synthesis from Carbon Dioxide. ACS Catal 2019. [DOI: 10.1021/acscatal.9b04309] [Citation(s) in RCA: 130] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Cheng Zhou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Jiaqing Shi
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Wei Zhou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Kang Cheng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Qinghong Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Jincan Kang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Ye Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
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Papastergiou M, Chriti D, Damalas DE, Raptopoulos G, Paraskevopoulou P. Poly(urethane-acrylate) aerogels from the isocyanurate trimer of isophorone diisocyanate. J Supercrit Fluids 2019. [DOI: 10.1016/j.supflu.2019.02.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Li W, Zhang Q, Zeng A. Controlled synthesis of CuxMn3.66−xMo3O12 with the citrate sol–gel method for the selective liquid-phase toluene oxidation to benzaldehyde by air. REACTION KINETICS MECHANISMS AND CATALYSIS 2018. [DOI: 10.1007/s11144-018-1413-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Papastergiou M, Kanellou A, Chriti D, Raptopoulos G, Paraskevopoulou P. Poly(Urethane-Acrylate) Aerogels via Radical Polymerization of Dendritic Urethane-Acrylate Monomers. MATERIALS (BASEL, SWITZERLAND) 2018; 11:E2249. [PMID: 30424515 PMCID: PMC6266260 DOI: 10.3390/ma11112249] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 10/28/2018] [Accepted: 11/07/2018] [Indexed: 11/16/2022]
Abstract
The purpose of this work was to investigate the effect of multifunctionality on material properties of synthetic polymer aerogels. For this purpose, we present the synthesis and characterization of monolithic dendritic-type urethane-acrylate monomers based on an aliphatic/flexible (Desmodur N3300), or an aromatic/rigid (Desmodur RE) triisocyanate core. The terminal acrylate groups (three at the tip of each of the three branches, nine in total) were polymerized with 2,2'-azobis(isobutyronitrile) (AIBN) via free radical chemistry. The resulting wet-gels were dried with supercritical fluid (SCF) CO₂. Aerogels were characterized with ATR-FTIR and solid-state 13C NMR. The porous network was probed with N₂-sorption and scanning electron microscopy (SEM). The thermal stability of aerogels was studied with thermogravimetric analysis (TGA). Most aerogels were macroporous materials (porosity > 80%), with high thermal stability (up to 300 °C). Aerogels were softer at low monomer concentrations and more rigid at higher concentrations. The material properties were compared with those of analogous aerogels bearing only one acrylate moiety at the tip of each branch and the same cores, and with those of analogous aerogels bearing norbornene instead of acrylate moieties. The nine-terminal acrylate-based monomers of this study caused rapid decrease of the solubility of the growing polymer and made possible aerogels with much smaller particles and much higher surface areas. For the first time, aliphatic/flexible triisocyanate-based materials could be made with similar properties in terms of particle size and surface areas to their aromatic/rigid analogues. Finally, it was found that with monomers with a high number of crosslinkable groups, material properties are determined by multifunctionality and thus aerogels based on 9-acrylate- and 9-norbornene-terminated monomers were similar. Materials with aromatic cores are carbonizable with satisfactory yields (20⁻30% w/w) to mostly microporous materials (BET surface areas: 640⁻740 m² g-1; micropore surface areas: 360⁻430 m² g-1).
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Affiliation(s)
- Maria Papastergiou
- Laboratory of Inorganic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, Athens 15771, Greece.
| | - Aspasia Kanellou
- Laboratory of Inorganic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, Athens 15771, Greece.
| | - Despoina Chriti
- Laboratory of Inorganic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, Athens 15771, Greece.
| | - Grigorios Raptopoulos
- Laboratory of Inorganic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, Athens 15771, Greece.
| | - Patrina Paraskevopoulou
- Laboratory of Inorganic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, Athens 15771, Greece.
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Kehrle J, Purkait TK, Kaiser S, Raftopoulos KN, Winnacker M, Ludwig T, Aghajamali M, Hanzlik M, Rodewald K, Helbich T, Papadakis CM, Veinot JGC, Rieger B. Superhydrophobic Silicon Nanocrystal-Silica Aerogel Hybrid Materials: Synthesis, Properties, and Sensing Application. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:4888-4896. [PMID: 29606005 DOI: 10.1021/acs.langmuir.7b03746] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Silicon nanocrystals (SiNCs) are abundant and exhibit exquisitely tailorable optoelectronic properties. The incorporation of SiNCs into highly porous and lightweight substrates such as aerogels leads to hybrid materials possessing the attractive features of both materials. This study describes the covalent deposition of SiNCs on and intercalation into silica aerogels, explores the properties, and demonstrates a prototype sensing application of the composite material. SiNCs of different sizes were functionalized with triethoxyvinylsilane (TEVS) via a radical grafting approach and subsequently used for the synthesis of photoluminescent silica hybrids. The resulting SiNC-containing aerogels possess high porosities, SiNC-based size-dependent photoluminescence, transparency, and a superhydrophobic macroscopic surface. The materials were used to examine the photoluminescence response toward low concentrations of 3-nitrotoluene (270 μM), demonstrating their potential as a sensing platform for high-energy materials.
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Affiliation(s)
| | - Tapas K Purkait
- Department of Chemistry , Johns Hopkins University , Baltimore , Maryland 21218 , United States
| | | | - Konstantinos N Raftopoulos
- Physik Weicher Materie , Technische Universität München , James-Frank-Str. 1 , 85748 Garching bei München , Germany
| | | | | | - Maryam Aghajamali
- Department of Chemistry , University of Alberta , 11227 Saskatchewan Drive , Edmonton , Alberta T6G 2G2 , Canada
| | | | | | | | - Christine M Papadakis
- Physik Weicher Materie , Technische Universität München , James-Frank-Str. 1 , 85748 Garching bei München , Germany
| | - Jonathan G C Veinot
- Department of Chemistry , University of Alberta , 11227 Saskatchewan Drive , Edmonton , Alberta T6G 2G2 , Canada
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10
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White LS, Selden T, Bertino MF, Cartin C, Angello J, Schwan M, Milow B, Ratke L. Fabrication of Mechanically Strong Honeycombs with Aerogel Cores. Ind Eng Chem Res 2018. [DOI: 10.1021/acs.iecr.7b04058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | | | - Marina Schwan
- Institute
of Materials Research, German Aerospace Center (DLR), 51170 Cologne, Germany
| | - Barbara Milow
- Institute
of Materials Research, German Aerospace Center (DLR), 51170 Cologne, Germany
| | - Lorenz Ratke
- Institute
of Materials Research, German Aerospace Center (DLR), 51170 Cologne, Germany
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11
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Hydrogen Production by Steam Reforming of Ethanol Over Mesoporous Ni–Al2O3–ZrO2 Catalysts. CATALYSIS SURVEYS FROM ASIA 2017. [DOI: 10.1007/s10563-017-9230-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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12
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Cheng Y, Zhou S, Hu P, Zhao G, Li Y, Zhang X, Han W. Enhanced mechanical, thermal, and electric properties of graphene aerogels via supercritical ethanol drying and high-temperature thermal reduction. Sci Rep 2017; 7:1439. [PMID: 28469261 PMCID: PMC5431159 DOI: 10.1038/s41598-017-01601-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 03/29/2017] [Indexed: 11/09/2022] Open
Abstract
Graphene aerogels with high surface areas, ultra-low densities and thermal conductivities have been prepared to exploit their wide applications from pollution adsorption to energy storage, supercapacitor, and thermal insulation. However, the low mechanical properties, poor thermal stability and electric conductivity restrict these aerogels' applications. In this paper, we prepared mechanically strong graphene aerogels with large BET surface areas, low thermal conductivities, high thermal stability and electric conductivities via hydrothermal reduction and supercritical ethanol drying. Annealing at 1500 °C resulted in slightly increased thermal conductivity and further improvement in mechanical properties, oxidation temperature and electric conductivity of the graphene aerogel. The large BET surface areas, together with strong mechanical properties, low thermal conductivities, high thermal stability and electrical conductivities made these graphene aerogels feasible candidates for use in a number of fields covering from batteries to sensors, electrodes, lightweight conductor and insulation materials.
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Affiliation(s)
- Yehong Cheng
- Science and Technology on Advanced Composites in Special Environment Laboratory, Harbin Institute of Technology, Harbin, 150080, People's Republic of China
| | - Shanbao Zhou
- Science and Technology on Advanced Composites in Special Environment Laboratory, Harbin Institute of Technology, Harbin, 150080, People's Republic of China
| | - Ping Hu
- Science and Technology on Advanced Composites in Special Environment Laboratory, Harbin Institute of Technology, Harbin, 150080, People's Republic of China
| | - Guangdong Zhao
- Science and Technology on Advanced Composites in Special Environment Laboratory, Harbin Institute of Technology, Harbin, 150080, People's Republic of China
| | - Yongxia Li
- Science and Technology on Advanced Composites in Special Environment Laboratory, Harbin Institute of Technology, Harbin, 150080, People's Republic of China
| | - Xinghong Zhang
- Science and Technology on Advanced Composites in Special Environment Laboratory, Harbin Institute of Technology, Harbin, 150080, People's Republic of China.
| | - Wenbo Han
- Science and Technology on Advanced Composites in Special Environment Laboratory, Harbin Institute of Technology, Harbin, 150080, People's Republic of China.
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Rechberger F, Niederberger M. Synthesis of aerogels: from molecular routes to 3-dimensional nanoparticle assembly. NANOSCALE HORIZONS 2017; 2:6-30. [PMID: 32260673 DOI: 10.1039/c6nh00077k] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Colloidal nanocrystals are extensively used as building blocks in nanoscience, and amazing results have been achieved in assembling them into ordered, close-packed structures. But in spite of great efforts, the size of these structures is typically restricted to a few micrometers, and it is very hard to extend them into the macroscopic world. In comparison, aerogels are macroscopic materials, highly porous, disordered, ultralight and with immense surface areas. With these distinctive characteristics, they are entirely contrary to common nanoparticle assemblies such as superlattices or nanocrystal solids, and therefore cover a different range of applications. While aerogels are traditionally synthesized by molecular routes based on aqueous sol-gel chemistry, in the last few years the gelation of nanoparticle dispersions became a viable alternative to improve the crystallinity and to widen the structural, morphological and compositional complexity of aerogels. In this Review, the different approaches to inorganic non-siliceous and non-carbon aerogels are addressed. We start our discussion with wet chemical routes involving molecular precursors, followed by processing methods using nanoparticles as building blocks. A unique feature of many of these routes is the fact that a macroscopic, often monolithic body is produced by pure self-assembly of nanosized colloids without the need for any templates.
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Affiliation(s)
- Felix Rechberger
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, CH-8093 Zurich, Switzerland.
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Marras C, Loche D, Carta D, Casula MF, Schirru M, Cutrufello MG, Corrias A. Copper-Based Catalysts Supported on Highly Porous Silica for the Water Gas Shift Reaction. Chempluschem 2016; 81:421-432. [PMID: 31968748 DOI: 10.1002/cplu.201500395] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 01/29/2016] [Indexed: 11/05/2022]
Abstract
Copper-based nanoparticles, supported on either a silica aerogel or cubic mesostructured silicas obtained by using two different synthetic protocols, were used as catalysts for the water gas shift reaction. The obtained nanocomposites were thoroughly characterised before and after catalysis through nitrogen adsorption-desorption measurements at -196 °C, TEM, and wide- and low-angle XRD. The samples before catalysis contained nanoparticles of copper oxides (either CuO or Cu2 O), whereas the formation of metallic copper nanoparticles, constituting the active catalytic phase, was observed either by using pre-treatment in a reducing atmosphere or directly during the catalytic reaction owing to the presence of carbon monoxide. A key role in determining the catalytic performances of the samples is played by the ability of different matrices to promote a high dispersion of copper metal nanoparticles. The best catalytic performances are obtained with the aerogel sample, which also exhibits constant carbon monoxide conversion values at constant temperature and reproducible behaviour after subsequent catalytic runs. On the other hand, in the catalysts based on cubic mesostructured silica, the detrimental effects related to sintering of copper nanoparticles are avoided only on the silica support, which is able to produce a reasonable dispersion of the copper nanophase.
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Affiliation(s)
- Claudia Marras
- Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario di Monserrato, s.s. 554 Bivio per Sestu, 09042, Monserrato CA, Italy
| | - Danilo Loche
- Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario di Monserrato, s.s. 554 Bivio per Sestu, 09042, Monserrato CA, Italy
| | - Daniela Carta
- Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario di Monserrato, s.s. 554 Bivio per Sestu, 09042, Monserrato CA, Italy
| | - Maria Francesca Casula
- Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario di Monserrato, s.s. 554 Bivio per Sestu, 09042, Monserrato CA, Italy
| | - Manuela Schirru
- Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario di Monserrato, s.s. 554 Bivio per Sestu, 09042, Monserrato CA, Italy
| | - Maria Giorgia Cutrufello
- Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario di Monserrato, s.s. 554 Bivio per Sestu, 09042, Monserrato CA, Italy
| | - Anna Corrias
- Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario di Monserrato, s.s. 554 Bivio per Sestu, 09042, Monserrato CA, Italy.,School of Physical Sciences, Ingram Building, University of Kent, Canterbury, CT2 7NH, UK
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Raissi S, Kamoun N, Younes MK, Ghorbel A. Effect of drying conditions on the textural, structural and catalytic properties of Cr/ZrO2–SO4: n-hexane conversion. REACTION KINETICS MECHANISMS AND CATALYSIS 2015. [DOI: 10.1007/s11144-015-0853-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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16
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Kopylovich MN, Ribeiro AP, Alegria EC, Martins NM, Martins LM, Pombeiro AJ. Catalytic Oxidation of Alcohols. ADVANCES IN ORGANOMETALLIC CHEMISTRY 2015. [DOI: 10.1016/bs.adomc.2015.02.004] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Low Concentration Fe-Doped Alumina Catalysts Using Sol-Gel and Impregnation Methods: The Synthesis, Characterization and Catalytic Performance during the Combustion of Trichloroethylene. MATERIALS 2014; 7:2062-2086. [PMID: 28788556 PMCID: PMC5453295 DOI: 10.3390/ma7032062] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 02/26/2014] [Accepted: 03/04/2014] [Indexed: 11/29/2022]
Abstract
The role of iron in two modes of integration into alumina catalysts was studied at 0.39 wt% Fe and tested in trichloroethylene combustion. One modified alumina was synthesized using the sol-gel method with Fe added in situ during hydrolysis; another modification was performed using calcined alumina, prepared using the sol-gel method and impregnated with Fe. Several characterization techniques were used to study the level of Fe modification in the γ-Al2O3 phase formed and to correlate the catalytic properties during trichloroethylene (TCE) combustion. The introduction of Fe in situ during the sol-gel process influenced the crystallite size, and three iron species were generated, namely, magnetite, maghemite and hematite. The impregnated Fe-alumina formed hematite and maghemite, which were highly dispersed on the γ-Al2O3 surface. The X-ray photoelectron spectra (XPS), FT-IR and Mössbauer spectroscopy analyses revealed how Fe interacted with the γ-Al2O3 lattice in both catalysts. The impregnated Fe-catalyst showed the best catalytic performance compared to the catalyst that was Fe-doped in situ by the sol-gel method; both had better catalytic activity than pure alumina. This difference in activity was correlated with the accessibility of the reactants to the hematite iron species on the surface. The chlorine poisoning for all three catalysts was less than 1.8%.
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18
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Heath L, Zhu L, Thielemans W. Chitin nanowhisker aerogels. CHEMSUSCHEM 2013; 6:537-44. [PMID: 23335426 PMCID: PMC3615177 DOI: 10.1002/cssc.201200717] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 11/23/2012] [Indexed: 05/21/2023]
Abstract
Chitin nanowhiskers are structured into mesoporous aerogels by using the same benign process used previously in our group to make cellulose nanowhisker aerogels. The nanowhiskers are sonicated in water to form a hydrogel before solvent-exchange with ethanol and drying under supercritical CO2 (scCO2 ). Aerogels are prepared with various densities and porosities, relating directly to the initial chitin nanowhisker content. scCO2 drying enables the mesoporous network structure to be retained as well as allowing the gel to retain its initial dimensions. The chitin aerogels have low densities (0.043-0.113 g cm(-3) ), high porosities (up to 97 %), surface areas of up to 261 m(2) g(-1) , and mechanical properties at the high end of other reported values (modulus between 7 and 9.3 MPa). The aerogels were further characterized by using X-ray diffraction, BET analysis, electron microscopy, FTIR, and thermogravimetric analysis. Characterization showed that the rod-like crystalline nature of the nanowhiskers was retained during the aerogel production process, making the aerogel truly an assembled structure of chitin nanocrystals. These aerogels also showed the lowest reported shrinkage during drying to date, with an average shrinkage of only 4 %.
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Affiliation(s)
- Lindy Heath
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK
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19
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Wingfield C, Franzel L, Bertino MF, Leventis N. Fabrication of functionally graded aerogels, cellular aerogels and anisotropic ceramics. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm10898k] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Heiligtag FJ, Rossell MD, Süess MJ, Niederberger M. Template-free co-assembly of preformed Au and TiO2 nanoparticles into multicomponent 3D aerogels. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm11740h] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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21
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Matějová L, Cajthaml T, Matěj Z, Benada O, Klusoň P, Šolcová O. Super/subcritical fluid extractions for preparation of the crystalline titania. J Supercrit Fluids 2010. [DOI: 10.1016/j.supflu.2009.12.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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22
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Rashidi F, Kharat AN, Rashidi AM, Lima E, Lara V, Valente JS. Fractal Geometry Approach to Describe Mesostructured Boehmite and Gamma-Alumina Nanorods. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.200901103] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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23
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Abstract
Silica or various silicate aerogels can be characterized by highly porous, open cell, low density structures. The synthesis parameters influence the three-dimensional porous structures by modifying the kinetics and mechanism of hydrolysis and condensation processes. Numerous investigations have shown that the structure of porous materials can be tailored by variations in synthesis conditions (e.g., the type of precursors, catalyst, and surfactants; the ratio of water/precursor; the concentrations; the medium pH; and the solvent). The objectives of this review are to summarize and elucidate the effects of chemical conditions on the nanoporous structure of sol-gel derived silicate aerogels.
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24
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Augustyn V, Dunn B. Vanadium oxide aerogels: Nanostructured materials for enhanced energy storage. CR CHIM 2010. [DOI: 10.1016/j.crci.2009.05.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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25
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Affiliation(s)
- Tsunetake Seki
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Hönggerberg, HCI, CH-8093 Zurich, Switzerland
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26
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Jaenicke S, Chuah GK, Raju V, Nie YT. Structural and Morphological Control in the Preparation of High Surface Area Zirconia. CATALYSIS SURVEYS FROM ASIA 2008. [DOI: 10.1007/s10563-008-9048-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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27
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28
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Savin SLP, Chadwick AV, O'dell LA, Smith ME. Characterisation of Nanocrystalline Magnesium Oxide by X-Ray Absorption Spectroscopy. Chemphyschem 2007; 8:882-9. [PMID: 17387669 DOI: 10.1002/cphc.200600750] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
There are numerous methods of preparing nanocrystalline materials. Magnesium oxide is an ideal model system on which to probe the relation of the preparative route and the microstructure. Using X-ray absorption spectroscopy (XAS) we show that the sol-gel route can be used to prepare highly crystalline material provided there is careful control of the calcination conditions. In the present work this is achieved by calcining at high temperatures (at least 800 degrees C). However, this results in grain growth that can be prevented by the addition of a pinning agent, SiO(2), during the preparation of the sol. The pinned samples maintain a particle size of 11 nm even after calcining at 1000 degrees C. Ball-milling is a common method of preparing nanocrystalline oxides, however the present work shows that this produces a significant fraction of amorphous material, the fraction increasing with decreasing grain size (e.g. approximately 30 % for a grain size of 23 nm).
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Affiliation(s)
- Shelley L P Savin
- Functional Materials Group, School of Physical Sciences, University of Kent, Canterbury, Kent CT2 7NR, UK
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29
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Kolen'ko YV, Kovnir KA, Gavrilov AI, Garshev AV, Meskin PE, Churagulov BR, Bouchard M, Colbeau-Justin C, Lebedev OI, Van Tendeloo G, Yoshimura M. Structural, Textural, and Electronic Properties of a Nanosized Mesoporous ZnxTi1-xO2-x Solid Solution Prepared by a Supercritical Drying Route. J Phys Chem B 2005; 109:20303-9. [PMID: 16853626 DOI: 10.1021/jp0535341] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mesoporous nanosized TiO2 and Zn(x)Ti(1-x)O(2-x) solid solution having a Zn content below 10 mol % with a particles size between 13 and 17 nm are prepared by a template-free sol-gel method followed by high-temperature supercritical drying in 2-propanol. The structural, textural, and electronic properties of the obtained nanomaterials are methodically investigated by using XRD, SEM, TEM, ED, HREM, EDX, ICP-OES, N(2) adsorption-desorption, Raman spectroscopy, and diffuse reflectance UV-vis spectroscopy. It is shown that the proposed synthesis technique leads to the formation of a Zn(x)Ti(1-x)O(2-x) solid solution based on the anatase crystal structure rather than a two-phase sample. High-resolution electron microscopy and electron diffraction indicate that the distribution of zinc atoms over the anatase structure does not lead to a considerable deformation of the crystal structure.
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Affiliation(s)
- Yury V Kolen'ko
- Materials and Structures Laboratory (Center for Materials Design), Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
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30
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Photocatalytic activity of sol–gel derived titania converted into nanocrystalline powders by supercritical drying. J Photochem Photobiol A Chem 2005. [DOI: 10.1016/j.jphotochem.2004.11.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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31
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Vinogradova E, Moreno A, Lara VH, Bosch P. Multi-fractal imaging and structural investigation of silica hydrogels and aerogels. ACTA ACUST UNITED AC 2005. [DOI: 10.1007/s11201-005-3391-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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32
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Corberán VC. Novel approaches for the improvement of selectivity in the oxidative activation of light alkanes. Catal Today 2005. [DOI: 10.1016/j.cattod.2004.09.055] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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33
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Sanchez C, Julián B, Belleville P, Popall M. Applications of hybrid organic–inorganic nanocomposites. ACTA ACUST UNITED AC 2005. [DOI: 10.1039/b509097k] [Citation(s) in RCA: 2119] [Impact Index Per Article: 111.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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34
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Kopylovich M, Kirillov A, Baev A, Pombeiro A. Heteronuclear iron(III)–chromium(III) hydroxo complexes and hydroxides, and their catalytic activity towards peroxidative oxidation of alkanes. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1381-1169(03)00420-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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35
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Salavati-Niasari M, Banitaba S. Alumina-supported Mn(II), Co(II), Ni(II) and Cu(II) bis(2-hydroxyanil)acetylacetone complexes as catalysts for the oxidation of cyclohexene with tert-butylhydroperoxide. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1381-1169(03)00128-6] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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36
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Murphy EF, Ferri D, Baiker A, Van Doorslaer S, Schweiger A. Novel routes to Cu(salicylaldimine) covalently bound to silica: combined pulse EPR and in situ attenuated total reflection-IR studies of the immobilization. Inorg Chem 2003; 42:2559-71. [PMID: 12691562 DOI: 10.1021/ic020298p] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Several novel routes for the immobilization of modified Cu(salicylaldimine) complexes on commercially available silica are described. New pulse electron paramagnetic resonance (EPR) and electron-nuclear double resonance sequences, which provide more detailed information than that available previously, in combination with continuous wave EPR, allow a definitive assignment of the geometry at the copper center in the immobilized Cu(salicylaldimine). Immobilization of the modified Cu(salicylaldimine) on silica was followed in situ by monitoring the intensity of the characteristic free- and metal-coordinated imine bands as a function of time using attenuated total reflectance IR spectroscopy. On the basis of these studies, the outcome of the Schiff base condensation of Cu-bis(salicylaldehyde) with gamma-aminopropyl-modified silica gel is shown to provide immobilized trans-O(2)N(2)- and O(3)N-coordinated immobilized Cu(salicylaldimine)-type compounds. In addition, trans-O(2)N(2)- or O(3)N-coordinated copper centers are selectively prepared on silica by controlling the aminopropyl modifier loading, thus opening a route to compounds not available by conventional synthesis. The O(3)N-coordinated Cu(salicylaldimine)-type compound on silica was investigated as a precursor for the synthesis of a tethered chiral Cu(salicylaldimine) via reaction of the coordinated carbonyl group with (R)-(+)-alpha-methylbenzylamine. Supported Cu(salicylaldimine) was also prepared via the immobilization of the appropriate silylethoxy-modified homogeneous precursor on silica gel. Precursors and silica-supported Cu(salicylaldimine) materials have been fully characterized. Comparisons are drawn with related Cu(salicylaldimine) immobilized in silica aerogels.
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Affiliation(s)
- Eamonn F Murphy
- Laboratory of Technical Chemistry, Swiss Federal Institute of Technology, ETH Hönggerberg-HCI, CH-8093 Zurich, Switzerland
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37
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Rolison DR. Catalytic nanoarchitectures--the importance of nothing and the unimportance of periodicity. Science 2003; 299:1698-701. [PMID: 12637736 DOI: 10.1126/science.1082332] [Citation(s) in RCA: 919] [Impact Index Per Article: 43.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Heterogeneous catalysis has always been an inherently nanoscopic phenomenon with important technological and societal consequences for energy conversion and the production of chemicals. New opportunities for improved performance arise when the multifunctionality inherent in catalytic processes, including molecular transport of reactants and products, is rethought in light of architectures designed and fabricated from the appropriate nanoscale building blocks, including the use of "nothing" (void space) and deliberate disorder as design components. Architectures with all of the appropriate electrochemical and catalytic requirements, including large surface areas readily accessible to molecules, may now be assembled on the benchtop. Designing catalytic nanoarchitectures that depart from the hegemony of periodicity and order offers the promise of even higher activity.
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Affiliation(s)
- Debra R Rolison
- Advanced Electrochemical Materials Section, Naval Research Laboratory, Code 6171, Washington, DC 20375, USA.
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38
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Zhang H, Li Y, Duan L, Lan Y, Wang E, Hu C, Yao Y, Chen J, Gao S. [{(NiOH)2Mo10O36(PO4)Ti2}n]5n−: a novel chainlike trimetal heteropolyanion based on pseudo-keggin fragments. J SOLID STATE CHEM 2003. [DOI: 10.1016/s0022-4596(02)00059-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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39
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Beck C, Mallat T, Baiker A. Epoxidation with Ti(OSiMe3)4: a homogeneous model mimicking titania–silica mixed oxides? NEW J CHEM 2003. [DOI: 10.1039/b300809f] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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40
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Šefčík J, Rankin SE. Monte Carlo Simulations of Size and Structure of Gel Precursors in Silica Polycondensation. J Phys Chem B 2002. [DOI: 10.1021/jp026361d] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ján Šefčík
- Swiss Federal Institute of Technology Zürich, Laboratorium für Technische Chemie, ETH Hönggerberg/HCI, CH-8093 Zürich, Switzerland, and Chemical and Materials Engineering Department, University of Kentucky, 177 Anderson Hall, Lexington, Kentucky 40506-0046
| | - Stephen E. Rankin
- Swiss Federal Institute of Technology Zürich, Laboratorium für Technische Chemie, ETH Hönggerberg/HCI, CH-8093 Zürich, Switzerland, and Chemical and Materials Engineering Department, University of Kentucky, 177 Anderson Hall, Lexington, Kentucky 40506-0046
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Lee SH, Jin Suh D, Park TJ, Kim KL. The effect of heat treatment conditions on the textural and catalytic properties of nickel–titania composite aerogel catalysts. CATAL COMMUN 2002. [DOI: 10.1016/s1566-7367(02)00175-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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42
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Corma A, García H. Lewis acids as catalysts in oxidation reactions: from homogeneous to heterogeneous systems. Chem Rev 2002; 102:3837-92. [PMID: 12371904 DOI: 10.1021/cr010333u] [Citation(s) in RCA: 406] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Avelino Corma
- Instituto de Tecnología Química CSIC-UPV, Avda. de los Naranjos s/n, Universidad Politécnica de Valencia, 46022 Valencia, Spain.
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Kholdeeva O, Trukhan N, Vanina M, Romannikov V, Parmon V, Mrowiec-Białoń J, Jarzębski A. A new environmentally friendly method for the production of 2,3,5-trimethyl-p-benzoquinone. Catal Today 2002. [DOI: 10.1016/s0920-5861(02)00070-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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44
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Bokhimi X, Sánchez-Valente J, Pedraza F. Crystallization of Sol–Gel Boehmite via Hydrothermal Annealing. J SOLID STATE CHEM 2002. [DOI: 10.1006/jssc.2002.9579] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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45
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Manganese Oxide–Silica Aerogels: Synthesis and Structural and Catalytic Properties in the Selective Oxidation of NH3. J Catal 2002. [DOI: 10.1006/jcat.2002.3532] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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46
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Decomposition of Nickel Formate on Sol–Gel Alumina and Characterization of Product by X-Ray Photoelectron and TOF-SIMS Spectroscopies. J Catal 2002. [DOI: 10.1006/jcat.2001.3317] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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47
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Zhuang Q, Miller JM. Sol-gel synthesis of ternary phosphate-ZrO2-SiO2 catalysts for alcohol dehydration. CAN J CHEM 2001. [DOI: 10.1139/v01-108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PhosphateZrO2Si2O catalysts were synthesized by sol-gel method using tributyl phosphite, zirconium propoxide, and tetraethyl orthosilicate as precursors. They were characterized by N2 adsorption, 31P CP MAS NMR, and DRIFTS. At lower P content, monomeric phosphates were formed on the surface of the catalysts, which were mainly responsible for the isopropanol dehydration activity. At higher P content, polyphosphates were formed, and thus, the dehydration activity decreased. An optimum P content for dehydration activity was found to be at 10 mol%.Key words: sol-gel synthesis, ternary oxides, phosphate, acid catalyst, alcohol dehydration, 31P CP MAS NMR, N2 adsorption, DRIFTS.
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48
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Zhuang Q, Miller JM. One-pot sol-gel synthesis of sulfated ZrO2-SiO2 catalysts for alcohol dehydration. CAN J CHEM 2001. [DOI: 10.1139/v01-109] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sulfated ZrO2SiO2 catalysts were synthesized by one-pot sol-gel method using ammonium sulfate, zirconium propoxide, and tetraethyl orthosilicate as precursors. The catalysts were characterized by N2 adsorption and DRIFTS. On calcining the gel at elevated temperature, the ammonium sulfate decomposed, giving a sulfated zirconiasilica catalyst. By adding ammonium sulfate to the sol-gel synthesis system, the surface area, pore size, and pore volume of the resultant catalyst were increased. The one-pot sol-gel synthesized catalyst with an optimum loading of SO42 14 mol% showed significantly higher catalytic activity, with a selectivity of 100%, for isopropanol dehydration when compared to the impregnated catalyst. The one-pot sol-gel synthesis method is an effective way to prepare sulfated zirconia catalyst.Key words: sulfated zirconia, sol-gel synthesis, acid catalyst, alcohol dehydration, N2 adsorption, DRIFT.
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Bozorgzadeh H, Kemnitz E, Nickkho-Amiry M, Skapin T, Winfield J. Catalytic reactions of chlorofluoroethanes at fluorinated alumina and chromia aerogels and xerogels. J Fluor Chem 2001. [DOI: 10.1016/s0022-1139(01)00427-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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50
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Trukhan N, Romannikov V, Paukshtis E, Shmakov A, Kholdeeva O. Oxidation of 2,3,6-Trimethylphenol over Ti- and V-Containing Mesoporous Mesophase Catalysts: Structure–Activity/Selectivity Correlation. J Catal 2001. [DOI: 10.1006/jcat.2001.3264] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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