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Deng KC, Lu ZX, Sun JJ, Ye JY, Dong F, Su HS, Yang K, Sartin MM, Yan S, Cheng J, Zhou ZY, Ren B. Accelerated interfacial proton transfer for promoting the electrocatalytic activity. Chem Sci 2022; 13:10884-10890. [PMID: 36320703 PMCID: PMC9491081 DOI: 10.1039/d2sc01750d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 08/23/2022] [Indexed: 11/21/2022] Open
Abstract
Interfacial pH is critical to electrocatalytic reactions involving proton-coupled electron transfer (PCET) processes, and maintaining an optimal interfacial pH at the electrochemical interface is required to achieve high activity. However, the interfacial pH varies inevitably during the electrochemical reaction owing to slow proton transfer at the interfacial layer, even in buffer solutions. It is therefore necessary to find an effective and general way to promote proton transfer for regulating the interfacial pH. In this study, we propose that promoting proton transfer at the interfacial layer can be used to regulate the interfacial pH in order to enhance electrocatalytic activity. By adsorbing a bifunctional 4-mercaptopyridine (4MPy) molecule onto the catalyst surface via its thiol group, the pyridyl group can be tethered on the electrochemical interface. The pyridyl group acts as both a good proton acceptor and donor for promoting proton transfer at the interfacial layer. Furthermore, the pKa of 4MPy can be modulated with the applied potentials to accommodate the large variation of interfacial pH under different current densities. By in situ electrochemical surface-enhanced Raman spectroscopy (in situ EC-SERS), we quantitatively demonstrate that proton transfer at the interfacial layer of the Pt catalyst coated with 4MPy (Pt@4MPy) remains ideally thermoneutral during the H+ releasing electrocatalytic oxidation reaction of formic acid (FAOR) at high current densities. Thus, the interfacial pH is controlled effectively. In this way, the FAOR apparent current measured from Pt@4MPy is twice that measured from a pristine Pt catalyst. This work establishes a general strategy for regulating interfacial pH to enhance the electrocatalytic activities. Adsorbing 4MPy on Pt surface promotes proton transfer at the interfacial layer, maintaining an optimal interfacial pH and promotes electrocatalytic reactions involving proton-coupled electron transfer (PCET) processes.![]()
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Affiliation(s)
- Kai-Chao Deng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
| | - Zhi-Xuan Lu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
| | - Juan-Juan Sun
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
| | - Jin-Yu Ye
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
- Fujian Science and Technology Innovation Laboratory for Energy Materials of China China
| | - Fan Dong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
| | - Hai-Sheng Su
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
| | - Kang Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
| | - Matthew M Sartin
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
| | - Sen Yan
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
| | - Jun Cheng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
- Fujian Science and Technology Innovation Laboratory for Energy Materials of China China
| | - Zhi-You Zhou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
- Fujian Science and Technology Innovation Laboratory for Energy Materials of China China
| | - Bin Ren
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
- Fujian Science and Technology Innovation Laboratory for Energy Materials of China China
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Vericat C, Vela ME, Corthey G, Pensa E, Cortés E, Fonticelli MH, Ibañez F, Benitez GE, Carro P, Salvarezza RC. Self-assembled monolayers of thiolates on metals: a review article on sulfur-metal chemistry and surface structures. RSC Adv 2014. [DOI: 10.1039/c4ra04659e] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
A review article on fundamental aspects of thiolate self-assembled monolayers (SAMs) on the (111) and (100) surfaces of the Cu and Ni groups is presented.
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Affiliation(s)
- C. Vericat
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- Universidad Nacional de La Plata-CONICET
- La Plata, Argentina
| | - M. E. Vela
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- Universidad Nacional de La Plata-CONICET
- La Plata, Argentina
| | - G. Corthey
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- Universidad Nacional de La Plata-CONICET
- La Plata, Argentina
| | - E. Pensa
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- Universidad Nacional de La Plata-CONICET
- La Plata, Argentina
| | - E. Cortés
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- Universidad Nacional de La Plata-CONICET
- La Plata, Argentina
| | - M. H. Fonticelli
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- Universidad Nacional de La Plata-CONICET
- La Plata, Argentina
| | - F. Ibañez
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- Universidad Nacional de La Plata-CONICET
- La Plata, Argentina
| | - G. E. Benitez
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- Universidad Nacional de La Plata-CONICET
- La Plata, Argentina
| | - P. Carro
- Departamento de Química
- Area Química Física. Instituto de Materiales y Nanotecnología
- Universidad de La Laguna
- , Spain
| | - R. C. Salvarezza
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- Universidad Nacional de La Plata-CONICET
- La Plata, Argentina
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Yang YC, Taranovskyy A, Magnussen OM. In situ video-STM studies of methyl thiolate surface dynamics and self-assembly on Cu(100) electrodes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:14143-14154. [PMID: 22967093 DOI: 10.1021/la302939f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The atomic-scale surface dynamic behavior of adsorbed methyl thiolate on Cu(100) electrodes, prepared via the dissociative adsorption of dimethyl disulfide, was studied in 0.01 M HCl solution over a wide regime of coverages. Using video-rate in situ STM, we directly observed the motion of the adsorbates within the c(2 × 2) lattice of the chloride coadsorbates with high spatial and temporal resolution, revealing complex mutual interactions of the organic adsorbates as well as pronounced interactions with Cu adatoms, which significantly affect the thiolate self-assembly. Quantitative measurements of the tracer diffusion of isolated thiolates reveal a 35 meV lower diffusion barrier as compared to that of sulfide adsorbates with a linear potential dependence of 0.5 eV/V. The effective intermolecular interactions between the thiolates resemble those between adsorbed sulfide and are repulsive at the nearest-neighbor distance of a(0) within the c(2 × 2) lattice, attractive at the next-nearest-neighbor distance of √2a(0) and again repulsive at a distance of 2a(0). Thiolates at these small spacings are found to exhibit characteristic collective properties, which are significant for the self-assembly of these species: First, their mobility is greatly enhanced relative to that of isolated thiolates. Second, Cu adatoms can be transiently trapped in between the two thiolates of a metastable dimer with an intermolecular spacing of √2a(0). With increasing coverage, small, highly mobile molecular clusters and subsequently the formation of ordered adlayer domains with a c(2 × 6) structure are observed. Common structural elements of the clusters and c(2 × 6) domains are stripes of thiolate dimers, which are oriented in the [011] direction, spaced at distances of √2a(0) and of which a large fraction is occupied by Cu adatoms. The c(2 × 6) phase can be rationalized as a close-packed arrangement of these dimer stripes. Because of the self-acceleration of the thiolate mobility, the ordering and reorganization of the ordered c(2 × 6) adlayers occur orders of magnitude faster than the surface diffusion of isolated thiolates, illustrating the importance of collective effects in organic self-organization.
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Affiliation(s)
- Yaw-Chia Yang
- Institute of Experimental and Applied Physics, Christian-Albrechts University Kiel, Olshausenstr. 40, 24098 Kiel, Germany
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Wang Y, Solano-Canchaya JG, Alcamí M, Busnengo HF, Martín F. Commensurate Solid–Solid Phase Transitions in Self-Assembled Monolayers of Alkylthiolates Lying on Metal Surfaces. J Am Chem Soc 2012; 134:13224-7. [PMID: 22827341 DOI: 10.1021/ja305842t] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Y. Wang
- Departamento de Química,
Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Cantoblanco, Madrid, Spain
| | - J. G. Solano-Canchaya
- Instituto de Física Rosario
(CONICET-UNR), Facultad de Ciencias Exactas, Ingeniería y Agrimensura, Universidad Nacional de Rosario, Avenida Pellegrini
250, 2000 Rosario, Argentina
| | - M. Alcamí
- Departamento de Química,
Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - H. F. Busnengo
- Instituto de Física Rosario
(CONICET-UNR), Facultad de Ciencias Exactas, Ingeniería y Agrimensura, Universidad Nacional de Rosario, Avenida Pellegrini
250, 2000 Rosario, Argentina
| | - F. Martín
- Departamento de Química,
Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Cantoblanco, Madrid, Spain
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Garcia JL, Tongol BJV, Yau SL. Dynamic self-assembly and electropolymerization processes of 3,4-ethylenedioxythiophene on Au(1 0 0) single crystal electrode as probed by in situ scanning tunneling microscopy. Electrochim Acta 2012. [DOI: 10.1016/j.electacta.2012.04.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Aoki M, Kamada T, Sasaki K, Masuda S, Morikawa Y. Chemisorption-induced gap states at organic–metal interfaces: benzenethiol and benzeneselenol on metal surfaces. Phys Chem Chem Phys 2012; 14:4101-8. [DOI: 10.1039/c2cp23206e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Tu H, Yen P, Chen S, Yau S, Dow WP, Lee YL. In situ STM imaging of bis-3-sodiumsulfopropyl-disulfide molecules adsorbed on copper film electrodeposited on Pt(111) single crystal electrode. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:6801-6807. [PMID: 21526808 DOI: 10.1021/la200250m] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The adsorption of bis-3-sodiumsulfopropyldi-sulfide (SPS) on metal electrodes in chloride-containing media has been intensively studied to unveil its accelerating effect on Cu electrodeposition. Molecular resolution scanning tunneling microscopy (STM) imaging technique was used in this study to explore the adsorption and decomposition of SPS molecules concurring with the electrodeposition of copper on an ordered Pt(111) electrode in 0.1 M HClO(4) + 1 mM Cu(ClO(4))(2) + 1 mM KCl. Depending on the potential of Pt(111), SPS molecules could react, adsorb, and decompose at chloride-capped Cu films. A submonolayer of Cu adatoms classified as the underpotential deposition (UPD) layer at 0.4 V (vs Ag/AgCl) was completely displaced by SPS molecules, possibly occurring via RSSR (SPS) + Cl-Cu-Pt → RS(-)-Pt(+) + RS(-) (MPS) + Cu(2+) + Cl(-), where MPS is 3-mercaptopropanesulfonate. By contrast, at 0.2 V, where a full monolayer of Cu was presumed to be deposited, SPS molecules were adsorbed in local (4 × 4) structures at the lower ends of step ledges. Bulk Cu deposition driven by a small overpotential (η < 50 mV) proceeded slowly to yield an atomically smooth Cu deposit at the very beginning (<5 layers). On a bilayer Cu deposit, the chloride adlayer was still adsorbed to afford SPS admolecules arranged in a unique 1D striped phase. SPS molecules could decompose into MPS upon further Cu deposition, as a (2 × 2)-MPS structure was observed with prolonged in situ STM imaging. It was possible to visualize either SPS admolecules in the upper plane or chloride adlayer sitting underneath upon switching the imaging conditions. Overall, this study established a MPS molecular film adsorbed to the chloride adlayer sitting atop the Cu deposit.
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Affiliation(s)
- HsinLing Tu
- Department of Chemistry, National Central University, Jhongli, Taiwan 320, ROC
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Masuda S, Kamada T, Sasaki K, Aokia M, Morikawa Y. Chemisorption-induced gap state at organic–metal interface: Benzenethiol on Pt(111). Phys Chem Chem Phys 2010; 12:10914-8. [DOI: 10.1039/c001016b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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10
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Petroski J, Chou M, Creutz C. The coordination chemistry of gold surfaces: Formation and far-infrared spectra of alkanethiolate-capped gold nanoparticles. J Organomet Chem 2009. [DOI: 10.1016/j.jorganchem.2008.11.057] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Liu YF, Yang YC, Lee YL. Assembly behavior and monolayer characteristics of OH-terminated alkanethiol on Au(111): in situ scanning tunneling microscopy and electrochemical studies. NANOTECHNOLOGY 2008; 19:065609. [PMID: 21730707 DOI: 10.1088/0957-4484/19/6/065609] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Self-assembled monolayers (SAMs) of 6-mercapto-1-hexanol (MHO) on an Au(111) electrode were prepared in an electrochemical system. The adsorption behavior of MHO and the time-dependent organization of the SAM were investigated by in situ scanning tunneling microscopy (STM) and cyclic voltammetry (CV). The results show that a potential higher than 0.28 V (relative to RHE) is required to induce the adsorption of MHO. At 0.28 V, the MHO molecules adsorb in a flat-lying orientation, forming an ordered striped phase with a molecular arrangement of ([Formula: see text]). However, the adlayer is not stable at this potential. The adsorbed striped phase may recover to the herringbone feature of the gold substrate due to the desorption of adsorbed MHO. At a higher potential (0.35 V), the adlayer becomes stable and can undergo a phase evolution from the striped phase to a condensed structure, identified as c([Formula: see text]). This structure can also be described as a c(4 × 2) superlattice of a [Formula: see text] hexagonal adlattice. The surface coverage of the MHO SAM is identical to the saturated structure of an 11-mercapto-1-undecanol (MUO) SAM reported in a previous work, [Formula: see text]. However, the STM image of MHO adlayer shows a modulation in intensity, reflecting the presence of various conformations of adsorbed molecules. This result is attributed to the shorter chain length of MHO, which gives a weaker van der Waals interaction between adsorbed molecules. This effect also results in a higher charge permeability across the adlayer and a lower striping potential to an MHO SAM.
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Affiliation(s)
- Yung-Fang Liu
- Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan
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Yang YC, Lee YL, Yang LYO, Yau SL. In situ scanning tunneling microscopy of 1,6-hexanedithiol, 1,9-nonanedithiol, 1,2-benzenedithiol, and 1,3-benzenedithiol adsorbed on pt(111) electrodes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:5189-95. [PMID: 16700612 DOI: 10.1021/la0529815] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Cyclic voltammetry (CV) and in situ scanning tunneling microscopy (STM) were used to examine four dithiol molecules, including 1,6-hexanedithiol, 1,9-nonanedithiol, 1,2-benzenedithiol, and 1,3-benzenedithiol, adsorbed on well-ordered Pt(111) electrodes in 0.1 M HClO(4). The open-circuit potential (OCP) of Pt(111) electrodes decreased substantially from 0.95 to 0.3 V (versus reversible hydrogen electrode) upon the adsorption of dithol molecules, which indicates that these adsorbates injected electrons into the Pt electrode. For all dithiol molecules, ordered adlattices of p(2 x 2) and (square root 3 x square root 3)R30 degrees were formed when the dosing concentration was lower than 150 microM and the potential of Pt(111) was more negative than 0.5 V. Raising the potential of Pt(111) from 0.1 to 0.4 V or more positive values could transform p(2 x 2) to (square root 3 x square root 3)R30 degrees before it turned disarray. The insensitivity of the structure of dithiol adlayers with their chemical structures was explained by upright molecular orientation with the formation of one Pt-S bond per dithiol molecule. This molecular orientation was independent of the coverage of dithiol molecules, as nucleation seeds produced at the beginning of adsorption were also constructed with p(2 x 2). The triangular-shaped STM molecular resolution suggested 3-fold binding of sulfur headgroup on Pt(111). All dithiols were adsorbed so strongly on Pt(111) electrodes that switching the potential negatively to the onset of hydrogen evolution in 0.1 M HClO(4) or water reduction in 1 M KOH could not displace dithiol admolecules.
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Affiliation(s)
- Yaw-Chia Yang
- Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan 701
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Noguchi H, Ito M, Uosaki K. Molecular Orientation of Self-assembled Monolayer of Octadecanethiol on Platinum Surface Studied by Femtosecond Broad-bandwidth Sum Frequency Generation Spectroscopy. CHEM LETT 2005. [DOI: 10.1246/cl.2005.950] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Lin TH, Huang TP, Liu YL, Yeh CC, Lai YH, Hung WH. Adsorption and Thermal Reactions of Alkanethiols on Pt(111): Dependence on the Length of the Alkyl Chain. J Phys Chem B 2005; 109:14079-84. [PMID: 16852768 DOI: 10.1021/jp058084r] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The adsorption and thermal decomposition of alkanethiols (R-SH, where R = CH3, C2H5, and C4H9) on Pt(111) were studied with temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS) with synchrotron radiation. Dissociation of sulfhydryl hydrogen (RS-H) of alkanethiol results in the formation of alkanethiolate; the extent of dissociation at an adsorption temperature of 110 K depends on the length of the alkyl chain. At small exposure, all chemisorbed CH3SH, C2H5SH, and C4H9SH decompose to desorb hydrogen below 370 K and yield carbon and sulfur on the surface. Desorption of products containing carbon is observed only at large exposure. In thermal decomposition, alkanethiolate is proposed to undergo a stepwise dehydrogenation: R'-CH2S --> R'-CHS --> R'-CS, R' = H, CH3, and C3H7. Further decomposition of the R'-CS intermediate results in desorption of H2 at 400-500 K and leaves carbon and sulfur on the surface. On the basis of TPD and XPS data, we conclude that the density of adsorption of alkanethiol decreases with increasing length of the alkyl chain. C4H9SH is proposed to adsorb mainly with a configuration in which its alkyl group interacts with the surface; this interaction diminishes the density of adsorption of alkanethiols but facilitates dehydrogenation of the alkyl group.
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Affiliation(s)
- T H Lin
- Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan
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