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Abstract With the aim of developing fuel cell applications that are capable of generating efficient electrical energy, much of the attention should be given to exploring new catalysts that could be less costly and more abundant than the most commonly used catalyst, platinum. This work explores nickel-based layered double hydroxide (Ni-LDH) as a fuel cell’s affordable catalyst for Oxygen Reduction Reaction (ORR). Ni-LDH was prepared and drop coated onto a Glassy Carbon Electrode (GCE) to conduct a 3-way electrode cyclic voltammetry using an oxygen-saturated aqueous sodium hydroxide (NaOH) solution as electrolyte. The electroanalytical study of the GCE-modified Ni-LDH working electrode showed an enhancement of both anodic and cathodic peaks because of the presence of oxygen at low temperatures. Data obtained from this experiment will serve as a reference for fuel cell systems in which Ni-LDH modified working electrodes are scaled up for comparison of area-specific properties.
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Unravelling the potential of disposable and modifiable pencils as catalyst supports for hydrogen evolution reaction
Increasing fossil fuel demands and growing concerns of global climate change have stimulated interest in the development of electrocatalysts to produce H 2 as an alternative zero-emission fuel from the electrolysis of water via hydrogen evolution reaction (HER). Precious or non-precious catalysts are typically loaded on high surface area carbon materials, and these supports play a critical role in both thermodynamics and kinetics of the HER. In this paper, we evaluate the electrocatalytic activity of a molecular hydrogen evolving catalyst, diacetyl-bis(4-methyl)-3-thiosemicarbazone Ni( ii ) (Ni-ATSM), on three different carbon surfaces: glassy carbon, carbon paste and pencil graphite. The overpotential for each modified electrode was benchmarked at a current density of −10 mA cm −2 . Carbon paste electrodes showed highest overpotentials (495 mV) compared to the other electrode surfaces. Polished pencil and glassy carbon modified electrodes performed similarly ( η = 395 mV for GCE and η = 400 mV for pencil). Pencil electrodes etched in acetone overnight prior to Ni-ATSM deposition produced lowest overpotentials ( η = 354 mV). Etching results in an increase in electroactive surface area and substantial decrease in the charge transfer resistance of the graphitic interface from 275 Ω to 50 Ω, verified using electrochemical impedance spectroscopy (EIS). Our studies demonstrate pencil graphite may serve as versatile, disposable, cost effective, and reproducible electrode surface for the evaluation of heterogeneous HER catalysts. Moreover, pencils can be easily cut with table saw to generate new surface for easy characterization of the surface such as electrochemistry, imaging and spectroscopy.
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- Award ID(s):
- 1955268
- PAR ID:
- 10422603
- Date Published:
- Journal Name:
- New Journal of Chemistry
- Volume:
- 46
- Issue:
- 39
- ISSN:
- 1144-0546
- Page Range / eLocation ID:
- 18832 to 18838
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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null (Ed.)The alkaline hydrogen evolution reaction (A-HER) holds great promise for clean hydrogen fuel generation but its practical utilization is severely hindered by the sluggish kinetics for water dissociation in alkaline solutions. Traditional ways to improve the electrochemical kinetics for A-HER catalysts have been focusing on surface modification, which still can not meet the demanding requirements for practical water electrolysis because of catalyst surface deactivation. Herein, we report an interior modification strategy to significantly boost the A-HER performance. Specifically, a trace amount of Pt was doped in the interior Co 2 P (Pt–Co 2 P) to introduce a stronger dopant–host interaction than that of the surface-modified catalyst. Consequently, the local chemical state and electronic structure of the catalysts were adjusted to improve the electron mobility and reduce the energy barriers for hydrogen adsorption and H–H bond formation. As a proof-of-concept, the interior-modified Pt–Co 2 P shows a reduced onset potential at near-zero volts for the A-HER, low overpotentials of 2 mV and 58 mV to achieve 10 and 100 mA cm −2 , and excellent durability for long-term utilization. The interior-modified Pt–Co 2 P delivers superior A-HER performance to Pt/C and other state-of-the-art electrocatalysts. This work will open a new avenue for A-HER catalyst design.more » « less
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Abstract The electrocatalytic hydrogen evolution reaction (HER) is one of the most studied and promising processes for hydrogen fuel generation. Single-atom catalysts have been shown to exhibit ultra-high HER catalytic activity, but the harsh preparation conditions and the low single-atom loading hinder their practical applications. Furthermore, promoting hydrogen evolution reaction kinetics, especially in alkaline electrolytes, remains as an important challenge. Herein, Pt/C60catalysts with high-loading, high-dispersion single-atomic platinum anchored on C60are achieved through a room-temperature synthetic strategy. Pt/C60-2 exhibits high HER catalytic performance with a low overpotential (η10) of 25 mV at 10 mA cm−2. Density functional theory calculations reveal that the Pt-C60polymeric structures in Pt/C60-2 favors water adsorption, and the shell-like charge redistribution around the Pt-bonding region induced by the curved surfaces of two adjacent C60facilitates the desorption of hydrogen, thus favoring fast reaction kinetics for hydrogen evolution.more » « less
- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/D2NJ03359C
