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Yu H, Gold JI, Wolter TJ, Bao N, Smith E, Zhang HA, Twieg RJ, Mavrikakis M, Abbott NL. Actuating Liquid Crystals Rapidly and Reversibly by Using Chemical Catalysis. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2309605. [PMID: 38331028 DOI: 10.1002/adma.202309605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 01/25/2024] [Indexed: 02/10/2024]
Abstract
Microtubules and catalytic motor proteins underlie the microscale actuation of living materials, and they have been used in reconstituted systems to harness chemical energy to drive new states of organization of soft matter (e.g., liquid crystals (LCs)). Such materials, however, are fragile and challenging to translate to technological contexts. Rapid (sub-second) and reversible changes in the orientations of LCs at room temperature using reactions between gaseous hydrogen and oxygen that are catalyzed by Pd/Au surfaces are reported. Surface chemical analysis and computational chemistry studies confirm that dissociative adsorption of H2 on the Pd/Au films reduces preadsorbed O and generates 1 ML of adsorbed H, driving nitrile-containing LCs from a perpendicular to a planar orientation. Subsequent exposure to O2 leads to oxidation of the adsorbed H, reformation of adsorbed O on the Pd/Au surface, and a return of the LC to its initial orientation. The roles of surface composition and reaction kinetics in determining the LC dynamics are described along with a proof-of-concept demonstration of microactuation of beads. These results provide fresh ideas for utilizing chemical energy and catalysis to reversibly actuate functional LCs on the microscale.
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Affiliation(s)
- Huaizhe Yu
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, 1 Ho Plaza, Ithaca, NY, 14853, USA
| | - Jake I Gold
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI, 53706, USA
| | - Trenton J Wolter
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI, 53706, USA
| | - Nanqi Bao
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, 1 Ho Plaza, Ithaca, NY, 14853, USA
| | - Evangelos Smith
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI, 53706, USA
| | - Hanyu Alice Zhang
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, 1 Ho Plaza, Ithaca, NY, 14853, USA
| | - Robert J Twieg
- Department of Chemistry and Biochemistry, Kent State University, 1175 Risman Drive, Kent, OH, 44242, USA
| | - Manos Mavrikakis
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI, 53706, USA
| | - Nicholas L Abbott
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, 1 Ho Plaza, Ithaca, NY, 14853, USA
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Fujita S, Baranton S, Coutanceau C, Jerkiewicz G. Electrochemical Behavior and Shape Evolution of Structured Pd Nanoparticles in Alkaline Media─Influence of Electrochemically Absorbed Hydrogen. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:15889-15900. [PMID: 37906432 DOI: 10.1021/acs.langmuir.3c01636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
We report on the electrochemical behavior and shape evolution of Pd nanocubes (Pd NCs) and Pd nanooctahedrons (Pd NOs) with an average size of 9.8 and 6.9 nm, respectively, in aqueous alkaline medium in the potential range of the underpotential deposition of H (UPD H) and H absorption. While the Pd NCs and Pd NOs remain stable in the potential region of the UPD H, H absorption and desorption of absorbed H (Habs) induce structural changes to the Pd NPs, as indicated by the results of electrochemical measurements and identical location-transmission electron microscopy (IL-TEM) analyses. Because both Pd NCs and Pd NOs are known to be stable in the potential region of H absorption and Habs desorption in acidic medium and maintain their structure, the irreversible structural changes are attributed to their interfacial interaction with the aqueous alkaline medium. In the alkaline medium, the nanoparticle surface/electrolyte interfacial structure plays an essential role in the mechanism of Habs desorption that is observed at higher potentials than that in the acidic medium. Hydrogen desorption is substantially hindered due to the structure of the water network adjacent to the Pd nanoparticles or the interaction between hydrated cations and adsorbed OH on the nanoparticle surface, resulting in the trapping of a small amount of H (incomplete Habs desorption). It is proposed that H trapping and associated structural strain lead to the deformation of the Pd nanoparticles and the loss of their initial structure.
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Affiliation(s)
- Sho Fujita
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada
| | - Stève Baranton
- IC2MP, UMR CNRS 7285, Université de Poitiers, 4 rue Michel Brunet, TSA 51106, 86073 Poitiers Cedex 9, France
| | - Christophe Coutanceau
- IC2MP, UMR CNRS 7285, Université de Poitiers, 4 rue Michel Brunet, TSA 51106, 86073 Poitiers Cedex 9, France
| | - Gregory Jerkiewicz
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada
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Critical role of hydrogen sorption kinetics in electrocatalytic CO2 reduction revealed by on-chip in situ transport investigations. Nat Commun 2022; 13:6911. [PMCID: PMC9663515 DOI: 10.1038/s41467-022-34685-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 10/31/2022] [Indexed: 11/16/2022] Open
Abstract
AbstractPrecise understanding of interfacial metal−hydrogen interactions, especially under in operando conditions, is crucial to advancing the application of metal catalysts in clean energy technologies. To this end, while Pd-based catalysts are widely utilized for electrochemical hydrogen production and hydrogenation, the interaction of Pd with hydrogen during active electrochemical processes is complex, distinct from most other metals, and yet to be clarified. In this report, the hydrogen surface adsorption and sub-surface absorption (phase transition) features of Pd and its alloy nanocatalysts are identified and quantified under operando electrocatalytic conditions via on-chip electrical transport measurements, and the competitive relationship between electrochemical carbon dioxide reduction (CO2RR) and hydrogen sorption kinetics is investigated. Systematic dynamic and steady-state evaluations reveal the key impacts of local electrolyte environment (such as proton donors with different pKa) on the hydrogen sorption kinetics during CO2RR, which offer additional insights into the electrochemical interfaces and optimization of the catalytic systems.
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Abstract
The constant phase element (CPE) is usually observed at solid electrodes. It is a source of controversies and misunderstandings. In this Viewpoint, theory, properties, experimental results, and the origin of the CPE are presented and discussed.
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Affiliation(s)
- Andrzej Lasia
- Département de chimie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
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Kim K, Byun J, Kim H, Lee KS, Lee HS, Kim J, Hyeon T, Kim JJ, Han JW. Systematic Approach to Designing a Highly Efficient Core–Shell Electrocatalyst for N 2O Reduction. ACS Catal 2021. [DOI: 10.1021/acscatal.1c03832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kyeounghak Kim
- Department of Chemical Engineering, Hanyang University, Seoul 04763, Republic of Korea
| | - Jinuk Byun
- School of Chemical and Biological Engineering, and Institute of Chemical Process, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyunjoong Kim
- School of Chemical and Biological Engineering, and Institute of Chemical Process, Seoul National University, Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
| | - Kug-Seung Lee
- Beamline Division, Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Hyeon Seok Lee
- School of Chemical and Biological Engineering, and Institute of Chemical Process, Seoul National University, Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
| | - Jiheon Kim
- School of Chemical and Biological Engineering, and Institute of Chemical Process, Seoul National University, Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
| | - Taeghwan Hyeon
- School of Chemical and Biological Engineering, and Institute of Chemical Process, Seoul National University, Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
| | - Jae Jeong Kim
- School of Chemical and Biological Engineering, and Institute of Chemical Process, Seoul National University, Seoul 08826, Republic of Korea
| | - Jeong Woo Han
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk 37673, Republic of Korea
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Mironova AA, Medvedeva NA, Kichigin VI, Skryabina NE, Fruchart D. Investigation of Hydrogen Evolution Reaction on (TiCr1.8)xV100 – x Alloys via Impedance Spectroscopy Method. RUSS J ELECTROCHEM+ 2021. [DOI: 10.1134/s1023193521080085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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7
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Sartorelli ML, Cutrim Gomes AM, de Pauli M, da Silva Reis CP, Serpa RB, Toledo Reis F, Jasinski EF, Chavero LN, Cavalcante RL, Galvão D, Ocubo Raulino Z, Zhou Y, Feng Y, von Windheim T, Vasquez Sanchez M, Ngaboyamahina E, Amsden JJ, Parker CB, Glass JT. Model-free capacitance analysis of electrodes with a 2D+1D dispersion of time constants. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.138796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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8
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Tuning hydrogen sorption properties of Pd by its alloying with Ru, Rh, and Pt: the study of binary alloys in concentrated alkaline media. J Solid State Electrochem 2020. [DOI: 10.1007/s10008-020-04776-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
AbstractThe hydrogen electrosorption process was examined in 6 M KOH on Pd binary alloys, containing Rh, Ru, and Pt. Pd-alloys were electrochemically deposited on Au substrate. The electrodes were subjected to activation procedure—hydrogen pretreatment procedure (HPP) at first in 0.5 M H2SO4 and then in 6 M KOH. It was noticed that it was possible to achieve comparable reversibility of hydrogen electrosorption process in acid and in concentrated base. The obtained values of the α→β phase transition potential, hysteresis extent, and maximum hydrogen absorption capacity show good agreement with the data from acidic medium. The observed kinetics of hydrogen electrosorption were strongly hindered in concentrated alkaline media, whereas the influence of the electrolyte on the thermodynamic functions of hydrogen absorption is less pronounced.
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9
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Effect of Hydrogen Electrosorption on Mechanical and Electronic Properties of Pd 80Rh 20 Alloy. MATERIALS 2020; 13:ma13010162. [PMID: 31906299 PMCID: PMC6982334 DOI: 10.3390/ma13010162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/19/2019] [Accepted: 12/26/2019] [Indexed: 12/02/2022]
Abstract
The interaction of hydrogen with Pt-group metals and alloys is at the center of research in the fields of electrochemistry, electrocatalysis, hydrogen technologies and fuel cells developed under the Hydrogen Economy. In this work, the material under study was Pd80Rh20 alloy (50 μm foil) subjected to hydrogen electrosorption at potentials corresponding to formation of α, α-β and β phase in 0.1 M H2SO4 at 25 °C. The total amount of hydrogen adsorbed at the surface and absorbed in octahedral interstitial positions of fcc Pd80Rh20 alloy, was determined from the oxidation charges. The H/(Pd+Rh) was 0.002, 0.4 and 0.8 for α, α-β, and β Pd80Rh20H, respectively. Microindentation hardness testing and nanoindentation showed weakening of mechanical properties of the Pd80Rh20 alloy after hydrogen electrosorption due to internal stresses. Decrease of work function with increasing amount of hydrogen absorbed occurred due to the surface roughness changes and the presence of electropositive hydrogen atoms absorbed in the crystal lattice responsible for the dipole interaction. The detailed mechanism of hydrogen absorption/diffusion in the Pd80Rh20 alloy structure is discussed. The obtained results give a new insight into the relationship between the amount of absorbed hydrogen and mechanical and electronic properties of the Pd80Rh20 alloy at the micro- and nanoscale.
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10
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Krawczyk P, Rozmanowski T, Frankowski M. Methanol Electrooxidation at Electrodes Made of Exfoliated Graphite/Nickel/Palladium Composite. Catal Letters 2019. [DOI: 10.1007/s10562-019-02785-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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11
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Enhanced kinetics of hydrogen electrosorption in AB5 hydrogen storage alloy decorated with Pd nanoparticles. Electrochem commun 2019. [DOI: 10.1016/j.elecom.2019.02.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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12
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Davydova ES, Mukerjee S, Jaouen F, Dekel DR. Electrocatalysts for Hydrogen Oxidation Reaction in Alkaline Electrolytes. ACS Catal 2018. [DOI: 10.1021/acscatal.8b00689] [Citation(s) in RCA: 211] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Elena S. Davydova
- The Wolfson Department of Chemical Engineering and the Nancy & Stephan Grand Technion Energy Program (GTEP), Technion − Israel Institute of Technology, Haifa 3200003, Israel
| | - Sanjeev Mukerjee
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Frédéric Jaouen
- Institut Charles
Gerhardt Montpellier, UMR 5253, CNRS, Université Montpellier,
ENSCM, 34095 Montpellier, France
| | - Dario R. Dekel
- The Wolfson Department of Chemical Engineering and the Nancy & Stephan Grand Technion Energy Program (GTEP), Technion − Israel Institute of Technology, Haifa 3200003, Israel
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13
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Insertion/Disinsertion of Hydrogen in Tailored Pd Layers Deposited on Pt(111) Surface in Alkaline and Acidic Medium. Electrocatalysis (N Y) 2017. [DOI: 10.1007/s12678-017-0414-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Hubkowska K, Soszko M, Symonowicz M, Łukaszewski M, Czerwiński A. Electrochemical Behavior of a Pd Thin Film Electrode in Concentrated Alkaline Media. Electrocatalysis (N Y) 2017. [DOI: 10.1007/s12678-017-0379-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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15
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Łosiewicz B, Jurczakowski R, Lasia A. Kinetics of hydrogen underpotential deposition at iridium in sulfuric and perchloric acids. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2016.12.116] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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16
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Lin D, Lasia A. Electrochemical impedance study of the kinetics of hydrogen evolution at a rough palladium electrode in acidic solution. J Electroanal Chem (Lausanne) 2017. [DOI: 10.1016/j.jelechem.2016.12.037] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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17
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Singh RK, Ramesh R, Devivaraprasad R, Chakraborty A, Neergat M. Hydrogen Interaction (Electrosorption and Evolution) Characteristics of Pd and Pd3Co Alloy Nanoparticles: An In-situ Investigation with Electrochemical Impedance Spectroscopy. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.01.231] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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18
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Januszewska A, Jurczakowski R, Kulesza PJ. CO₂ electroreduction at bare and Cu-decorated Pd pseudomorphic layers: catalyst tuning by controlled and indirect supporting onto Au(111). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:14314-14321. [PMID: 25350872 DOI: 10.1021/la5025247] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report here the results of electrochemical studies on CO2 electroreduction at multilayered catalyst composed of the monatomic layer of copper covering palladium overlayers (0.8-10 monolayers) deposited on the well-defined Au(111) surface. These multilayered systems were obtained by successive underpotential deposition steps: Pd on Au(111) as well as Cu on Pd/Au(111). Low index orientation of Au substrate was chosen to compare Pd overlayers with bulk Pd(111), which is known to reduce CO2 to CO adsorbates in acidic solutions. The process of CO2 electroreduction was studied by using classical transient electrochemical methods. Catalytic activity of bare Pd layers was investigated in acidic and neutral solutions. In the latter case, much higher activity of Pd overlayers was observed. The results showed that the palladium layer thickness significantly changed the catalytic activities of both bare Pd overlayers and the one Cu monolayer covered electrodes toward CO2 electroreduction. Results show that catalytic activity can be finely tuned by using the multilayered near-surface-alloy approach.
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Affiliation(s)
- Aneta Januszewska
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw , Zwirki i Wigury 101, PL-02-093 Warsaw, Poland
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19
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Enhanced corrosion resistance of mild steel in 1M hydrochloric acid solution by alkaloids extract from Aniba rosaeodora plant: Electrochemical, phytochemical and XPS studies. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2013.12.023] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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20
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Łukaszewski M, Hubkowska K, Koss U, Czerwiński A. On the Nature of Voltammetric Signals Originating from Hydrogen Electrosorption into Palladium-Noble Metal Alloys. MATERIALS 2013; 6:4817-4835. [PMID: 28788362 PMCID: PMC5452831 DOI: 10.3390/ma6104817] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 10/08/2013] [Accepted: 10/12/2013] [Indexed: 12/04/2022]
Abstract
Hydrogen sorption/desorption signals observed on cyclic voltammograms in experiments on hydrogen electrosorption into Pd-noble metal alloys (Pd-Au, Pd-Pt, Pd-Rh, Pd-Ru, Pd-Pt-Rh, Pd-Pt-Au) were characterized. The influence of electrosorption potential, scan rate and alloy bulk composition on the features of the hydrogen peaks was investigated. The experimental results were compared with those obtained on the basis of a model taken from the literature. It was confirmed that the rate of the α-β phase transition controls the overall rate of the process of hydrogen absorption/desorption into/from thin Pd-based electrodes. It was demonstrated that from the analysis of the changes of the hydrogen oxidation peak potential with the hydrogen electrosorption potential in cyclic voltammetric experiments it is possible to determine the limiting Pd bulk content, below which the β-phase in the alloy-hydrogen system is not formed.
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Affiliation(s)
- Mariusz Łukaszewski
- Department of Chemistry, Warsaw University, Pasteura 1, Warsaw 02-093, Poland.
| | - Katarzyna Hubkowska
- Department of Chemistry, Warsaw University, Pasteura 1, Warsaw 02-093, Poland.
| | - Urszula Koss
- Department of Chemistry, Warsaw University, Pasteura 1, Warsaw 02-093, Poland.
| | - Andrzej Czerwiński
- Department of Chemistry, Warsaw University, Pasteura 1, Warsaw 02-093, Poland.
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Córdoba-Torres P, Mesquita T, Nogueira R. Influence of geometry-induced current and potential distributions on the characterization of constant-phase element behavior. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2012.09.060] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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The method of limited volume electrodes as a tool for hydrogen electrosorption studies in palladium and its alloys. J Solid State Electrochem 2011. [DOI: 10.1007/s10008-011-1506-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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25
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Cai Y, Ma C, Zhu Y, Wang JX, Adzic RR. Low-coordination sites in oxygen-reduction electrocatalysis: their roles and methods for removal. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:8540-8547. [PMID: 21627139 DOI: 10.1021/la200753z] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Low-coordination sites, including edges, kinks, and defects, play an important role in oxygen-reduction electrocatalysis. Their role was studied experimentally and theoretically for various Pt surfaces. However, the roughness effect on similar-sized nanoparticles that could elucidate the role of low-coordination sites has attracted much less attention, with no studies on Pd nanoparticles. Here, using Br- adsorption/desorption, we introduce an effective approach to reduce surface roughness, yielding Pd nanoparticles with smoother surfaces and an increased number of (111)-oriented facets. The resulting nanoparticles have a slightly contracted structure and narrow size distribution. Pt monolayer catalysts that contain such nanoparticles as the cores showed a 1.5-fold enhancement in specific and Pt mass activities for the oxygen reduction reaction compared with untreated ones. Furthermore, a dramatic increase in durability was observed with bromide-treated Pd(3)Co cores. These results demonstrate a simple approach to preparing nanoparticles with smooth surfaces and confirm the adverse effect of low-coordination sites on the kinetics of the oxygen-reduction reaction.
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Affiliation(s)
- Yun Cai
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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26
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Aziznia A, Bonakdarpour A, Gyenge EL, Oloman CW. Electroreduction of nitrous oxide on platinum and palladium: Toward selective catalysts for methanol–nitrous oxide mixed-reactant fuel cells. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2011.03.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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27
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Łosiewicz B, Martin M, Lebouin C, Lasia A. Kinetics of hydrogen underpotential deposition at ruthenium in acidic solutions. J Electroanal Chem (Lausanne) 2010. [DOI: 10.1016/j.jelechem.2010.04.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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28
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Hirschorn B, Orazem ME, Tribollet B, Vivier V, Frateur I, Musiani M. Determination of effective capacitance and film thickness from constant-phase-element parameters. Electrochim Acta 2010. [DOI: 10.1016/j.electacta.2009.10.065] [Citation(s) in RCA: 1291] [Impact Index Per Article: 92.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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29
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Łukaszewski M, Hubkowska K, Czerwiński A. Electrochemical absorption and oxidation of hydrogen on palladium alloys with platinum, gold and rhodium. Phys Chem Chem Phys 2010; 12:14567-72. [DOI: 10.1039/c0cp00542h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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