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Purdy SC, Collinge G, Zhang J, Borate SN, Unocic KA, Wu Q, Wegener EC, Kropf AJ, Samad NR, Yuk SF, Zhang D, Habas S, Krause TR, Harris JW, Lee MS, Glezakou VA, Rousseau R, Sutton AD, Li Z. Dynamic Copper Site Redispersion through Atom Trapping in Zeolite Defects. J Am Chem Soc 2024; 146:8280-8297. [PMID: 38467029 DOI: 10.1021/jacs.3c13302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Single-site copper-based catalysts have shown remarkable activity and selectivity for a variety of reactions. However, deactivation by sintering in high-temperature reducing environments remains a challenge and often limits their use due to irreversible structural changes to the catalyst. Here, we report zeolite-based copper catalysts in which copper oxide agglomerates formed after reaction can be repeatedly redispersed back to single sites using an oxidative treatment in air at 550 °C. Under different environments, single-site copper in Cu-Zn-Y/deAlBeta undergoes dynamic changes in structure and oxidation state that can be tuned to promote the formation of key active sites while minimizing deactivation through Cu sintering. For example, single-site Cu2+ reduces to Cu1+ after catalyst pretreatment (270 °C, 101 kPa H2) and further to Cu0 nanoparticles under reaction conditions (270-350 °C, 7 kPa EtOH, 94 kPa H2) or accelerated aging (400-450 °C, 101 kPa H2). After regeneration at 550 °C in air, agglomerated CuO was dispersed back to single sites in the presence and absence of Zn and Y, which was verified by imaging, in situ spectroscopy, and catalytic rate measurements. Ab initio molecular dynamics simulations show that solvation of CuO monomers by water facilitates their transport through the zeolite pore, and condensation of the CuO monomer with a fully protonated silanol nest entraps copper and reforms the single-site structure. The capability of silanol nests to trap and stabilize copper single sites under oxidizing conditions could extend the use of single-site copper catalysts to a wider variety of reactions and allows for a simple regeneration strategy for copper single-site catalysts.
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Affiliation(s)
- Stephen C Purdy
- Manufacturing Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Gregory Collinge
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Junyan Zhang
- Manufacturing Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Shivangi N Borate
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Kinga A Unocic
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Qiyuan Wu
- Catalytic Carbon Transformation & Scale-Up Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Evan C Wegener
- Chemical Science and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - A Jeremy Kropf
- Chemical Science and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Nohor River Samad
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Simuck F Yuk
- Department of Chemistry and Life Science, United States Military Academy, West Point, New York 10996, United States
| | - Difan Zhang
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Susan Habas
- Catalytic Carbon Transformation & Scale-Up Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Theodore R Krause
- Chemical Science and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - James W Harris
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Mal-Soon Lee
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | | | - Roger Rousseau
- Chemical Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Andrew D Sutton
- Manufacturing Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Zhenglong Li
- Manufacturing Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
- Institute of Zhejiang University-Quzhou, Quzhou 324000, China
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Santos RMM, Briois V, Martins L, Santilli CV. Insights into the Preparation of Copper Catalysts Supported on Layered Double Hydroxide Derived Mixed Oxides for Ethanol Dehydrogenation. ACS APPLIED MATERIALS & INTERFACES 2021; 13:26001-26012. [PMID: 34043905 DOI: 10.1021/acsami.1c04541] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Acetaldehyde is an important chemical commodity and a building block for producing several other high-value products in the chemical industry. This has motivated the search for suitable, efficient, stable, and selective catalysts, as well as renewable raw materials such as ethanol. In this work, supported copper catalysts were prepared from CuZnAl layered double hydroxides (LDHs) with different copper contents (5, 10, and 20 wt %) for application in the ethanol dehydrogenation reaction (EDR). The samples were thoroughly characterized by a series of techniques, which allowed for analysis of all of the copper and zinc species involved in the different catalyst preparation steps and during the EDR. The results obtained by in situ quick extended X-ray absorption fine structure (EXAFS) measurements, combined with multivariate data analysis, showed that the copper content in the pristine LDH influenced the phase composition of the mixed oxide support, which consequently affected the dispersion of copper nanoparticles. The higher the copper content, the higher are the ZnAl2O4 and zinc tetrahedral prenuclei (TPN) contents, to the detriment of the ZnO content. All the samples showed high selectivity (>97%) and stability in the catalytic reactions at 300 and 350 °C, with no observed deactivation during 6 h on-stream. Although the samples with lower copper content presented higher copper dispersion and reactivity, the sample containing 20 wt % of copper outperformed the others, with greater conversion and higher activity toward acetaldehyde.
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Affiliation(s)
- Rodrigo M M Santos
- Institute of Chemistry, São Paulo State University (UNESP), Rua Prof. Francisco Degni 55, Araraquara, 14800-060 São Paulo, Brazil
- SOLEIL Synchrotron, L'Orme des Merisiers, BP48, Saint-Aubin, 91192 Gif-sur-Yvette, France
| | - Valérie Briois
- SOLEIL Synchrotron, L'Orme des Merisiers, BP48, Saint-Aubin, 91192 Gif-sur-Yvette, France
| | - Leandro Martins
- Institute of Chemistry, São Paulo State University (UNESP), Rua Prof. Francisco Degni 55, Araraquara, 14800-060 São Paulo, Brazil
| | - Celso V Santilli
- Institute of Chemistry, São Paulo State University (UNESP), Rua Prof. Francisco Degni 55, Araraquara, 14800-060 São Paulo, Brazil
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Copper–Zirconia Catalysts: Powerful Multifunctional Catalytic Tools to Approach Sustainable Processes. Catalysts 2020. [DOI: 10.3390/catal10020168] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Copper–zirconia catalysts find many applications in different reactions owing to their unique surface properties and relatively easy manufacture. The so-called methanol economy, which includes the CO2 and CO valorization and the hydrogen production, and the emerging (bio)alcohol upgrading via dehydrogenative coupling reaction, are two critical fields for a truly sustainable development in which copper–zirconia has a relevant role. In this review, we provide a systematic view on the factors most impacting the catalytic activity and try to clarify some of the discrepancies that can be found in the literature. We will show that contrarily to the large number of studies focusing on the zirconia crystallographic phase, in the last years, it has turned out that the degree of surface hydroxylation and the copper–zirconia interphase are in fact the two mostly determining factors to be controlled to achieve high catalytic performances.
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