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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Exploring Nickel Based Layered Double Hydroxides (LDH) as an Alternative of Platinum for Fuel Cell Applications
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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- Award ID(s):
- 1914751
- PAR ID:
- 10618618
- Publisher / Repository:
- American Society of Mechanical Engineers
- Date Published:
- ISBN:
- 978-0-7918-8864-3
- Format(s):
- Medium: X
- Location:
- Portland, Oregon, USA
- Sponsoring Org:
- National Science Foundation
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