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Pereira-Hernández XI, DeLaRiva A, Muravev V, Kunwar D, Xiong H, Sudduth B, Engelhard M, Kovarik L, Hensen EJM, Wang Y, Datye AK. Reply to: "Pitfalls in identifying active catalyst species". Nat Commun 2020; 11:4574. [PMID: 32917867 PMCID: PMC7486913 DOI: 10.1038/s41467-020-18193-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 08/06/2020] [Indexed: 12/02/2022] Open
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27
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Susman MD, Pham HN, Zhao X, West DH, Chinta S, Bollini P, Datye AK, Rimer JD. Synthesis of NiO Crystals Exposing Stable High‐Index Facets. Angew Chem Int Ed Engl 2020; 59:15119-15123. [DOI: 10.1002/anie.202003390] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Indexed: 11/10/2022]
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28
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Susman MD, Pham HN, Zhao X, West DH, Chinta S, Bollini P, Datye AK, Rimer JD. Synthesis of NiO Crystals Exposing Stable High‐Index Facets. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003390] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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29
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Unocic KA, Walden FS, Marthe NL, Datye AK, Bigelow WC, Allard LF. Introducing and Controlling Water Vapor in Closed-Cell In Situ Electron Microscopy Gas Reactions. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2020; 26:229-239. [PMID: 32157982 DOI: 10.1017/s1431927620000185] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Protocols for conducting in situ transmission electron microscopy (TEM) reactions using an environmental TEM with dry gases have been well established. However, many important reactions that are relevant to catalysis or high-temperature oxidation occur at atmospheric pressure and are influenced by the presence of water vapor. These experiments necessitate using a closed-cell gas reaction TEM holder. We have developed protocols for introducing and controlling water vapor concentrations in experimental gases from 2% at a full atmosphere to 100% at ~17 Torr, while measuring the gas composition using a residual gas analyzer (RGA) on the return side of the in situ gas reactor holder. Initially, as a model system, cube-shaped MgO crystals were used to help develop the protocols for handling the water vapor injection process and confirming that we could successfully inject water vapor into the gas cell. The interaction of water vapor with MgO triggered surface morphological and chemical changes as a result of the formation of Mg(OH)2, later validated with mass spectra obtained with our RGA system with and without water vapor. Integrating an RGA with an in situ scanning/TEM closed-cell gas reaction system can thus provide critical measurements correlating gas composition with dynamic surface restructuring of materials during reactions.
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Lu Y, Thompson C, Kunwar D, Datye AK, Karim AM. Origin of the High CO Oxidation Activity on CeO
2
Supported Pt Nanoparticles: Weaker Binding of CO or Facile Oxygen Transfer from the Support? ChemCatChem 2020. [DOI: 10.1002/cctc.201901848] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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31
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Huo J, Pham HN, Cheng Y, Lin HH, Roling LT, Datye AK, Shanks BH. Deactivation and regeneration of carbon supported Pt and Ru catalysts in aqueous phase hydrogenation of 2-pentanone. Catal Sci Technol 2020. [DOI: 10.1039/d0cy00163e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aqueous phase conversion of biomass-derived molecules requires development of catalysts and operating strategies that create viable operation for extended performance as necessitated for industrial applications.
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33
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Pereira-Hernández XI, DeLaRiva A, Muravev V, Kunwar D, Xiong H, Sudduth B, Engelhard M, Kovarik L, Hensen EJM, Wang Y, Datye AK. Tuning Pt-CeO 2 interactions by high-temperature vapor-phase synthesis for improved reducibility of lattice oxygen. Nat Commun 2019; 10:1358. [PMID: 30911011 PMCID: PMC6433950 DOI: 10.1038/s41467-019-09308-5] [Citation(s) in RCA: 155] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 02/15/2019] [Indexed: 12/02/2022] Open
Abstract
In this work, we compare the CO oxidation performance of Pt single atom catalysts (SACs) prepared via two methods: (1) conventional wet chemical synthesis (strong electrostatic adsorption–SEA) with calcination at 350 °C in air; and (2) high temperature vapor phase synthesis (atom trapping–AT) with calcination in air at 800 °C leading to ionic Pt being trapped on the CeO2 in a thermally stable form. As-synthesized, both SACs are inactive for low temperature (<150 °C) CO oxidation. After treatment in CO at 275 °C, both catalysts show enhanced reactivity. Despite similar Pt metal particle size, the AT catalyst is significantly more active, with onset of CO oxidation near room temperature. A combination of near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) and CO temperature-programmed reduction (CO-TPR) shows that the high reactivity at low temperatures can be related to the improved reducibility of lattice oxygen on the CeO2 support. While single-atom catalysts (SACs) have attracted a lot of interest, the nature of the active sites in SACs remains elusive. Here the authors elucidate that depositing single atoms via high temperature synthesis leads to improved reducibility of lattice oxygen on CeO2 yielding low temperature reactivity of Pt catalysts in CO oxidation.
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34
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Kunwar D, Zhou S, DeLaRiva A, Peterson EJ, Xiong H, Pereira-Hernández XI, Purdy SC, ter Veen R, Brongersma HH, Miller JT, Hashiguchi H, Kovarik L, Lin S, Guo H, Wang Y, Datye AK. Stabilizing High Metal Loadings of Thermally Stable Platinum Single Atoms on an Industrial Catalyst Support. ACS Catal 2019. [DOI: 10.1021/acscatal.8b04885] [Citation(s) in RCA: 155] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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35
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Xie J, Kammert JD, Kaylor N, Zheng JW, Choi E, Pham HN, Sang X, Stavitski E, Attenkofer K, Unocic RR, Datye AK, Davis RJ. Atomically Dispersed Co and Cu on N-Doped Carbon for Reactions Involving C–H Activation. ACS Catal 2018. [DOI: 10.1021/acscatal.8b00141] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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36
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Huo J, Duan P, Pham HN, Chan YJ, Datye AK, Schmidt-Rohr K, Shanks BH. Improved hydrothermal stability of Pd nanoparticles on nitrogen-doped carbon supports. Catal Sci Technol 2018. [DOI: 10.1039/c8cy00947c] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Carbon supports have been shown to provide better hydrothermal stability than alumina or silica supports, thus attracting more attention for aqueous-phase biomass conversion reactions.
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Huo J, Johnson RL, Duan P, Pham HN, Mendivelso-Perez D, Smith EA, Datye AK, Schmidt-Rohr K, Shanks BH. Stability of Pd nanoparticles on carbon-coated supports under hydrothermal conditions. Catal Sci Technol 2018. [DOI: 10.1039/c7cy02098h] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrothermal stability is one of the major challenges facing heterogeneous catalysis in biomass conversion to chemicals or fuels.
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38
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Nie L, Mei D, Xiong H, Peng B, Ren Z, Hernandez XIP, DeLaRiva A, Wang M, Engelhard MH, Kovarik L, Datye AK, Wang Y. Activation of surface lattice oxygen in single-atom Pt/CeO2 for low-temperature CO oxidation. Science 2017; 358:1419-1423. [DOI: 10.1126/science.aao2109] [Citation(s) in RCA: 828] [Impact Index Per Article: 118.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 09/06/2017] [Accepted: 11/13/2017] [Indexed: 01/21/2023]
Abstract
To improve fuel efficiency, advanced combustion engines are being designed to minimize the amount of heat wasted in the exhaust. Hence, future generations of catalysts must perform at temperatures that are 100°C lower than current exhaust-treatment catalysts. Achieving low-temperature activity, while surviving the harsh conditions encountered at high engine loads, remains a formidable challenge. In this study, we demonstrate how atomically dispersed ionic platinum (Pt2+) on ceria (CeO2), which is already thermally stable, can be activated via steam treatment (at 750°C) to simultaneously achieve the goals of low-temperature carbon monoxide (CO) oxidation activity while providing outstanding hydrothermal stability. A new type of active site is created on CeO2 in the vicinity of Pt2+, which provides the improved reactivity. These active sites are stable up to 800°C in oxidizing environments.
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Spezzati G, Su Y, Hofmann JP, Benavidez AD, DeLaRiva AT, McCabe J, Datye AK, Hensen EJM. Atomically Dispersed Pd-O Species on CeO 2(111) as Highly Active Sites for Low-Temperature CO Oxidation. ACS Catal 2017; 7:6887-6891. [PMID: 29034121 PMCID: PMC5634748 DOI: 10.1021/acscatal.7b02001] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/06/2017] [Indexed: 11/29/2022]
Abstract
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Ceria-supported Pd
is a promising heterogeneous catalyst for CO
oxidation relevant to environmental cleanup reactions. Pd loaded onto
a nanorod form of ceria exposing predominantly (111) facets is already
active at 50 °C. Here we report a combination of CO-FTIR spectroscopy
and theoretical calculations that allows assigning different forms
of Pd on the CeO2(111) surface during reaction conditions.
Single Pd atoms stabilized in the form of PdO and PdO2 in
a CO/O2 atmosphere participate in a catalytic cycle involving
very low activation barriers for CO oxidation. The presence of single
Pd atoms on the Pd/CeO2-nanorod, corroborated by aberration-corrected
TEM and CO-FTIR spectroscopy, is considered pivotal to its high CO
oxidation activity.
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Xiong H, Lin S, Goetze J, Pletcher P, Guo H, Kovarik L, Artyushkova K, Weckhuysen BM, Datye AK. Thermally Stable and Regenerable Platinum-Tin Clusters for Propane Dehydrogenation Prepared by Atom Trapping on Ceria. Angew Chem Int Ed Engl 2017; 56:8986-8991. [PMID: 28598531 PMCID: PMC5697674 DOI: 10.1002/anie.201701115] [Citation(s) in RCA: 158] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 05/22/2017] [Indexed: 11/20/2022]
Abstract
Ceria (CeO2) supports are unique in their ability to trap ionic platinum (Pt), providing exceptional stability for isolated single atoms of Pt. The reactivity and stability of single‐atom Pt species was explored for the industrially important light alkane dehydrogenation reaction. The single‐atom Pt/CeO2 catalysts are stable during propane dehydrogenation, but are not selective for propylene. DFT calculations show strong adsorption of the olefin produced, leading to further unwanted reactions. In contrast, when tin (Sn) is added to CeO2, the single‐atom Pt catalyst undergoes an activation phase where it transforms into Pt–Sn clusters under reaction conditions. Formation of small Pt–Sn clusters allows the catalyst to achieve high selectivity towards propylene because of facile desorption of the product. The CeO2‐supported Pt–Sn clusters are very stable, even during extended reaction at 680 °C. Coke formation is almost completely suppressed by adding water vapor to the feed. Furthermore, upon oxidation the Pt–Sn clusters readily revert to the atomically dispersed species on CeO2, making Pt–Sn/CeO2 a fully regenerable catalyst.
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41
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Xiong H, Lin S, Goetze J, Pletcher P, Guo H, Kovarik L, Artyushkova K, Weckhuysen BM, Datye AK. Thermally Stable and Regenerable Platinum–Tin Clusters for Propane Dehydrogenation Prepared by Atom Trapping on Ceria. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201701115] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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42
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Xie J, Yin K, Serov A, Artyushkova K, Pham HN, Sang X, Unocic RR, Atanassov P, Datye AK, Davis RJ. Selective Aerobic Oxidation of Alcohols over Atomically-Dispersed Non-Precious Metal Catalysts. CHEMSUSCHEM 2017; 10:359-362. [PMID: 27863066 DOI: 10.1002/cssc.201601364] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 10/28/2016] [Indexed: 06/06/2023]
Abstract
Catalytic oxidation of alcohols often requires the presence of expensive transition metals. Herein, it is shown that earth-abundant Fe atoms dispersed throughout a nitrogen-containing carbon matrix catalyze the oxidation of benzyl alcohol and 5-hydroxymethylfurfural by O2 in the aqueous phase. The activity of the catalyst can be regenerated by a mild treatment in H2 . An observed kinetic isotope effect indicates that β-H elimination from the alcohol is the kinetically relevant step in the mechanism, which can be accelerated by substituting Fe with Cu. Dispersed Cr, Co, and Ni also convert alcohols, demonstrating the general utility of metal-nitrogen-carbon materials for alcohol oxidation catalysis. Oxidation of aliphatic alcohols is substantially slower than that of aromatic alcohols, but addition of 2,2,6,6-tetramethyl-1-piperidinyloxy as a co-catalyst with Fe can significantly improve the reaction rate.
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43
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Kaylor N, Xie J, Kim YS, Pham HN, Datye AK, Lee YK, Davis RJ. Vapor phase deoxygenation of heptanoic acid over silica-supported palladium and palladium-tin catalysts. J Catal 2016. [DOI: 10.1016/j.jcat.2016.09.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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44
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Jones J, Xiong H, DeLaRiva AT, Peterson EJ, Pham H, Challa SR, Qi G, Oh S, Wiebenga MH, Pereira Hernández XI, Wang Y, Datye AK. Thermally stable single-atom platinum-on-ceria catalysts via atom trapping. Science 2016; 353:150-4. [PMID: 27387946 DOI: 10.1126/science.aaf8800] [Citation(s) in RCA: 873] [Impact Index Per Article: 109.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 06/13/2016] [Indexed: 01/21/2023]
Abstract
Catalysts based on single atoms of scarce precious metals can lead to more efficient use through enhanced reactivity and selectivity. However, single atoms on catalyst supports can be mobile and aggregate into nanoparticles when heated at elevated temperatures. High temperatures are detrimental to catalyst performance unless these mobile atoms can be trapped. We used ceria powders having similar surface areas but different exposed surface facets. When mixed with a platinum/aluminum oxide catalyst and aged in air at 800°C, the platinum transferred to the ceria and was trapped. Polyhedral ceria and nanorods were more effective than ceria cubes at anchoring the platinum. Performing synthesis at high temperatures ensures that only the most stable binding sites are occupied, yielding a sinter-resistant, atomically dispersed catalyst.
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45
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Jones J, Xiong H, DeLaRiva AT, Peterson EJ, Pham H, Challa SR, Qi G, Oh S, Wiebenga MH, Pereira Hernández XI, Wang Y, Datye AK. Thermally stable single-atom platinum-on-ceria catalysts via atom trapping. Science 2016. [PMID: 27387946 DOI: 10.1126/scienceaaf8800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Catalysts based on single atoms of scarce precious metals can lead to more efficient use through enhanced reactivity and selectivity. However, single atoms on catalyst supports can be mobile and aggregate into nanoparticles when heated at elevated temperatures. High temperatures are detrimental to catalyst performance unless these mobile atoms can be trapped. We used ceria powders having similar surface areas but different exposed surface facets. When mixed with a platinum/aluminum oxide catalyst and aged in air at 800°C, the platinum transferred to the ceria and was trapped. Polyhedral ceria and nanorods were more effective than ceria cubes at anchoring the platinum. Performing synthesis at high temperatures ensures that only the most stable binding sites are occupied, yielding a sinter-resistant, atomically dispersed catalyst.
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46
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Xie J, Huang B, Yin K, Pham HN, Unocic RR, Datye AK, Davis RJ. Influence of Dioxygen on the Promotional Effect of Bi during Pt-Catalyzed Oxidation of 1,6-Hexanediol. ACS Catal 2016. [DOI: 10.1021/acscatal.6b00972] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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47
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Pham HN, Sattler JHB, Weckhuysen BM, Datye AK. Role of Sn in the Regeneration of Pt/γ-Al 2O 3 Light Alkane Dehydrogenation Catalysts. ACS Catal 2016; 6:2257-2264. [PMID: 27076991 PMCID: PMC4822188 DOI: 10.1021/acscatal.5b02917] [Citation(s) in RCA: 130] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/22/2016] [Indexed: 11/20/2022]
Abstract
Alumina-supported Pt is one of the major industrial catalysts for light alkane dehydrogenation. This catalyst loses activity during reaction, with coke formation often considered as the reason for deactivation. As we show in this study, the amount and nature of carbon deposits do not directly correlate with the loss of activity. Rather, it is the transformation of subnanometer Pt species into larger Pt nanoparticles that appears to be responsible for the loss of catalytic activity. Surprisingly, a portion of the Sn remains atomically dispersed on the alumina surface in the spent catalyst and helps in the redispersion of the Pt. In the absence of Sn on the alumina support, the larger Pt nanoparticles formed during reaction are not redispersed during oxidative regeneration. It is known that Sn is added as a promoter in the industrial catalyst to help in achieving high propene selectivity and to minimize coke formation. This work shows that an important role of Sn is to help in the regeneration of Pt, by providing nucleation sites on the alumina surface. Aberration-corrected scanning transmission electron microscopy helps to provide unique insights into the operating characteristics of an industrially important catalyst by demonstrating the role of promoter elements, such as Sn, in the oxidative regeneration of Pt on γ-Al2O3.
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48
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Johns TR, Goeke RS, Ashbacher V, Thüne PC, Niemantsverdriet J, Kiefer B, Kim CH, Balogh MP, Datye AK. Relating adatom emission to improved durability of Pt–Pd diesel oxidation catalysts. J Catal 2015. [DOI: 10.1016/j.jcat.2015.03.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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49
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Pham HN, Anderson AE, Johnson RL, Schwartz TJ, O’Neill BJ, Duan P, Schmidt-Rohr K, Dumesic JA, Datye AK. Carbon Overcoating of Supported Metal Catalysts for Improved Hydrothermal Stability. ACS Catal 2015. [DOI: 10.1021/acscatal.5b00329] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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50
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Xiong H, Schwartz TJ, Andersen NI, Dumesic JA, Datye AK. Graphitic-Carbon Layers on Oxides: Toward Stable Heterogeneous Catalysts for Biomass Conversion Reactions. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201502206] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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