Hydrogen evolution reaction on gold electrode in alkaline solutions

Ohmori, Tadayoshi; Enyo, M.

doi:10.1016/0013-4686(92)87118-j

Cited by 36 publications

(20 citation statements)

References 7 publications

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“…While b seems independent on the presence of AE‐MoS x up to pH 5, Si/Ti/Au substrates exhibit slightly higher values in neutral to alkaline environments. Although the exact HER pathway on bare Au is still under debate, recent investigations in acidic electrolytes have found two characteristic Tafel slope values at low ( b ≈ 68 ± 5 mV dec −1 ) and high current densities ( b ≈ 120 ± 2 mV dec −1 ) due to hydrogen surface diffusion effects, converging to a Tafel slope of b ≈120 dec −1 in alkaline environments . AE‐MoS x films tested under stirring gave Tafel slopes with lower dispersion compared to their quiescent counterparts ( b ≈ 65 ± 10 mV dec −1 in the 0 ≤ pH ≤ 3 range closer to theoretical Volmer–Heyrovsky b ≈ 40 mV dec −1 as reported for AE‐MoS x in acid).…”

Section: Resultssupporting

confidence: 70%

Benchmarking the Activity, Stability, and Inherent Electrochemistry of Amorphous Molybdenum Sulfide for Hydrogen Production

Escalera‐López

Lou

Rees

2019

Advanced Energy Materials

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can be efficiently produced on demand and in a decentralized manner with (photo) electrochemical methods via the hydrogen evolution reaction (HER). [1][2][3][4] Despite of being the best performing HER catalysts, [5,6] noble metals such as Pt, Ir, and Pd are scarce and consequently hamper the viability of water electrolysis technologies. Hence earth-abundant materials, and notably transition metal dichalcogenides (TMDs) such as molybdenum disulfide (MoS 2 ), have been extensively investigated as HER electrocatalysts. [7][8][9][10][11] The edge sites-driven hydrogen electroadsorption properties of TMDs [12,13] have prompted the fabrication of amorphous molybdenum sulfide materials (MoS x ) to minimize exposure of the electrocatalytically inert MoS 2 basal planes [14] for multiple applications. [15][16][17][18][19] A simple, yet scalable method to fabricate MoS x has been reported by substrate-insensitive electrodeposition from a [MoS 4 ] 2− precursor, [20,21] and critical properties in MoS x materials such as film thickness, [22] morphology, [23][24][25][26] Mo:S stoichiometry, [27] as well as incorporation of dopants [28][29][30] or nanocomposite formation, [31][32][33][34][35] have been easily tuned by experimental parameters.For long-term electrocatalytic applications, however, HER activity and stability of TMDs are paramount. In crystalline MoS 2 , basal plane activation, [36][37][38][39][40][41][42][43] edge site exposure, [44][45][46][47][48][49][50][51][52][53] and metal doping/incorporation/intercalation [54][55][56][57][58][59][60][61][62][63][64][65][66] are the most employed strategies.In contrast, the [Mo 3 S 13 ] 2− cluster-based polymeric structure of electrodeposited MoS x[67] requires alternative approaches to maximize activity. In addition, the detailed HER mechanism as well as the true catalytically active sites are still under debate. Whilst pioneering studies on ambient pressure X-ray photoelectron spectroscopy (XPS) indicated the MoS 2 edge-like sites formed after MoS 3 phase transformation under in operando conditions responsible for the HER performance, [68] in situ X-ray absorption spectroscopy experiments suggested terminal S 2 2− ligands (S 2 2− terminal ) to be the proton acceptor sites, [69] and more recently in situ Raman spectroscopy indicated these to be the electrochemically cleaved bridging S 2 2− ligands (S 2 2− bridging ). [70] Another study claimed that unsaturated Mo centers formed after cathodic dissolution of S 2 2− terminal to be the true HER Anodically electrodeposited amorphous molybdenum sulfide (AE-MoS x ) has attracted significant attention as a non-noble metal electrocatalyst for its high activity toward the hydrogen evolution reaction (HER). The [Mo 3 S 13 ] 2− polymerbased structure confers a high density of exposed sulfur moieties, widely regarded as the HER active sites. However, their intrinsic complexity conceals full understanding of their exact role in HER catalysis, hampering their full potential for water splitting applications. In this report, a unifying app...

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Section: Resultssupporting

confidence: 70%

Benchmarking the Activity, Stability, and Inherent Electrochemistry of Amorphous Molybdenum Sulfide for Hydrogen Production

Escalera‐López

Lou

Rees

2019

Advanced Energy Materials

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“…54 In situ infrared (IR) spectroscopy indirectly supports a mechanism involving a low population of Au−H and rate-limiting CPET; although Pt−H bonds have been observed in in situ IR studies, [55][56][57] to our knowledge, surface Au−H bonds have never been observed. Although the reaction order in proton donor is expected to be unity for rate-limiting CPET, fractional orders have been observed in HER electrocatalysis, and have been attributed to adsorption phenomena, 58,59 which we do not believe to be operative in this case due to the independence of HER activity on base concentration (Figure S18 and S19). In this case, the fractional order is difficult to explain from experimentally attainable information.…”

Section: Discussionmentioning

confidence: 87%

Donor-Dependent Kinetics of Interfacial Proton-Coupled Electron Transfer

Jackson

Surendranath

2016

J. Am. Chem. Soc.

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The effect of the proton donor on the kinetics of interfacial concerted proton-electron transfer (CPET) to polycrystalline Au was probed indirectly by studying the rate of hydrogen evolution from trialkylammonium donors with different steric profiles, but the same pKa. Detailed kinetic studies point to a mechanism for HER catalysis that involves rate-limiting CPET from the proton donor to the electrode surface, allowing this catalytic reaction to serve as a proxy for the rate of interfacial CPET. In acetonitrile electrolyte, triethylammonium (TEAH(+)) displays up to 20-fold faster CPET kinetics than diisopropylethylammonium (DIPEAH(+)) at all measured potentials. In aqueous electrolyte, this steric constraint is largely lifted, suggesting a key role for water in mediating interfacial CPET. In acetonitrile, TEAH(+) also displays a much larger transfer coefficient (β = 0.7) than DIPEAH(+) (β = 0.4), and TEAH(+) displays a potential-dependent H/D kinetic isotope effect that is not observed for DIPEAH(+). These results demonstrate that proton donor structure strongly impacts the free energy landscape for CPET to extended solid surfaces and highlight the crucial role of the proton donor in the kinetics of electrocatalytic energy conversion reactions.

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“…However, once the current collector faces directly the electrolyte, hydrogen is easily evolved on the surface and might have a detrimental effect on the electrode. Although the 'hydrogen corrosion' is not the case for noble current collectors, [74][75][76][77][78] in case of stainless steel (316L and 304SU), it might additionally promote formation of protective layer [79][80][81][82][83][84][85] and then introduce another resistance to the system (observed most likely as ESR but also EDR increase). Interestingly, the postulated LiOH formation might also play a role in this process.…”

Section: Resultsmentioning

confidence: 99%

Towards more Durable Electrochemical Capacitors by Elucidating the Ageing Mechanisms under Different Testing Procedures

Fic

Frąckowiak

et al. 2018

ChemElectroChem

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Electrical double‐layer capacitors (EDLCs) commonly denoted supercapacitors are rechargeable energy storage devices with excellent power and energy delivery metrics intermediate to conventional capacitors and batteries. High‐voltage aqueous electrolyte based EDLCs are particularly attractive due to their high‐power capability, facile production, and environmental advantages. EDLCs should last for thousands of cycles and evaluation of future cell chemistries require long‐term and costly galvanostatic cycling. Voltage holding tests have been proposed to shorten evaluation time by accelerating cell degradation processes. Whether voltage holding can replace cycling completely remains undemonstrated. In this work, a systematic investigation of the influence of testing procedure on cell performance is presented. The state‐of‐the‐art post‐mortem and operando experimental techniques are implemented to elucidate ageing mechanisms and kinetics inside EDLC cells under different testing procedures. Carbon corrosion occurring on the positively polarized electrode leads to the lower active surface area and higher oxygen content. On the contrary, an increase of surface area and micropore volume are observed on the negatively polarized electrode. Repeated galvanostatic cycles at U <1.6 V appears to facilitate the depletion of oxygen species on the positively polarized electrode in comparison with voltage holding, which indicates a more complex degradation mechanism during cycling. Caution is advised when comparing results from different test procedures.

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Hydrogen evolution reaction on gold electrode in alkaline solutions

Cited by 36 publications

References 7 publications

Benchmarking the Activity, Stability, and Inherent Electrochemistry of Amorphous Molybdenum Sulfide for Hydrogen Production

Benchmarking the Activity, Stability, and Inherent Electrochemistry of Amorphous Molybdenum Sulfide for Hydrogen Production

Donor-Dependent Kinetics of Interfacial Proton-Coupled Electron Transfer

Towards more Durable Electrochemical Capacitors by Elucidating the Ageing Mechanisms under Different Testing Procedures

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