Nanoalloy Electrocatalysts for Electrochemical Devices

A special issue of Nanomaterials (ISSN 2079-4991). This special issue belongs to the section "Energy and Catalysis".

Deadline for manuscript submissions: closed (31 October 2021) | Viewed by 15760

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editor

Special Issue Information

Dear Colleagues,

Metallic, bimetallic, trimetallic, and other nanoalloy electrocatalysts have the potential to provide superior and cost-effective solutions to meet the requirements of contemporary and evolving electrochemical devices. The main factors that influence the catalytic activity of nanoalloys are the electronic, geometric and other poststructural effects, point defects, synergistic effects, surface strain, carbon-based stabilizers, etc. The fields of direct borohydride and alcohol fuel cells, batteries, supercapacitors, water electrolyzers, solar cells, sensors, electrochromic displays, electro-degradation devices and hydrogen peroxide producers, among others, offer key application opportunities for novel nanoalloys developed by new synthesis techniques, and presenting unique properties.

This Special Issue will cover the most recent advances in nanoalloy electrocatalysts, concerning, not only the synthesis, characterization, and modeling, but especially reports of their activity, functionality, durability, and low-cost for electrochemical devices.

Prof. Dr. César Augusto Correia de Sequeira
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Nanomaterials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2900 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • nanoalloys
  • electrocatalysts
  • synthesis of nanomaterials
  • modern electrochemical devices

Published Papers (7 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Editorial

Jump to: Research

5 pages, 225 KiB  
Editorial
Editorial for the Special Issue on “Nanoalloy Electrocatalysts for Electrochemical Devices”
by César A. C. Sequeira
Nanomaterials 2022, 12(1), 132; https://doi.org/10.3390/nano12010132 - 31 Dec 2021
Viewed by 1139
Abstract
Nanoscale science and technology dealing with materials synthesis, nanofabrication, nanoprobes, nanostructures, nanoelectronics, nano-optics, nanomechanics, nanodevices, nanobiotechnology, and nanomedicine is an exciting field of research and development in Europe, the United States, and other countries around the world [...] Full article
(This article belongs to the Special Issue Nanoalloy Electrocatalysts for Electrochemical Devices)

Research

Jump to: Editorial

17 pages, 3025 KiB  
Article
Synthesis and Characterization of PdAgNi/C Trimetallic Nanoparticles for Ethanol Electrooxidation
by Ahmed Elsheikh and James McGregor
Nanomaterials 2021, 11(9), 2244; https://doi.org/10.3390/nano11092244 - 30 Aug 2021
Cited by 12 | Viewed by 1960
Abstract
The direct use of ethanol in fuel cells presents unprecedented economic, technical, and environmental opportunities in energy conversion. However, complex challenges need to be resolved. For instance, ethanol oxidation reaction (EOR) requires breaking the rigid C–C bond and results in the generation of [...] Read more.
The direct use of ethanol in fuel cells presents unprecedented economic, technical, and environmental opportunities in energy conversion. However, complex challenges need to be resolved. For instance, ethanol oxidation reaction (EOR) requires breaking the rigid C–C bond and results in the generation of poisoning carbonaceous species. Therefore, new designs of the catalyst electrode are necessary. In this work, two trimetallic PdxAgyNiz/C samples are prepared using a facile borohydride reduction route. The catalysts are characterized by X-ray diffraction (XRD), Energy-Dispersive X-ray spectroscopy (EDX), X-ray photoelectron Spectroscopy (XPS), and Transmission Electron Microscopy (TEM) and evaluated for EOR through cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). The XRD patterns have shown a weak alloying potential between Pd, and Ag prepared through co-reduction technique. The catalysts prepared have generally shown enhanced performance compared to previously reported ones, suggesting that the applied synthesis may be suitable for catalyst mass production. Moreover, the addition of Ag and Ni has improved the Pd physiochemical properties and electrocatalytic performance towards EOR in addition to reducing cell fabrication costs. In addition to containing less Pd, The PdAgNi/C is the higher performing of the two trimetallic samples presenting a 2.7 A/mgPd oxidation current peak. The Pd4Ag2Ni1/C is higher performing in terms of its steady-state current density and electrochemical active surface area. Full article
(This article belongs to the Special Issue Nanoalloy Electrocatalysts for Electrochemical Devices)
Show Figures

Figure 1

24 pages, 3673 KiB  
Article
Carbon-Supported Trimetallic Catalysts (PdAuNi/C) for Borohydride Oxidation Reaction
by Ahmed M. A. ElSheikh, Gordana Backović, Raisa C. P. Oliveira, César A. C. Sequeira, James McGregor, Biljana Šljukić and Diogo M. F. Santos
Nanomaterials 2021, 11(6), 1441; https://doi.org/10.3390/nano11061441 - 29 May 2021
Cited by 8 | Viewed by 2791
Abstract
The synthesis of palladium-based trimetallic catalysts via a facile and scalable synthesis procedure was shown to yield highly promising materials for borohydride-based fuel cells, which are attractive for use in compact environments. This, thereby, provides a route to more environmentally friendly energy storage [...] Read more.
The synthesis of palladium-based trimetallic catalysts via a facile and scalable synthesis procedure was shown to yield highly promising materials for borohydride-based fuel cells, which are attractive for use in compact environments. This, thereby, provides a route to more environmentally friendly energy storage and generation systems. Carbon-supported trimetallic catalysts were herein prepared by three different routes: using a NaBH4-ethylene glycol complex (PdAuNi/CSBEG), a NaBH4-2-propanol complex (PdAuNi/CSBIPA), and a three-step route (PdAuNi/C3-step). Notably, PdAuNi/CSBIPA yielded highly dispersed trimetallic alloy particles, as determined by XRD, EDX, ICP-OES, XPS, and TEM. The activity of the catalysts for borohydride oxidation reaction was assessed by cyclic voltammetry and RDE-based procedures, with results referenced to a Pd/C catalyst. A number of exchanged electrons close to eight was obtained for PdAuNi/C3-step and PdAuNi/CSBIPA (7.4 and 7.1, respectively), while the others, PdAuNi/CSBEG and Pd/CSBIPA, presented lower values, 2.8 and 1.2, respectively. A direct borohydride-peroxide fuel cell employing PdAuNi/CSBIPA catalyst in the anode attained a power density of 47.5 mW cm−2 at room temperature, while the elevation of temperature to 75 °C led to an approximately four-fold increase in power density to 175 mW cm−2. Trimetallic catalysts prepared via this synthesis route have significant potential for future development. Full article
(This article belongs to the Special Issue Nanoalloy Electrocatalysts for Electrochemical Devices)
Show Figures

Graphical abstract

13 pages, 2616 KiB  
Article
Hydrogen Nanometrology in Advanced Carbon Nanomaterial Electrodes
by Rui Lobo, Noe Alvarez and Vesselin Shanov
Nanomaterials 2021, 11(5), 1079; https://doi.org/10.3390/nano11051079 - 22 Apr 2021
Cited by 3 | Viewed by 1931
Abstract
A comparative experimental study between advanced carbon nanostructured electrodes, in similar hydrogen uptake/desorption conditions, is investigated making use of the recent molecular beam-thermal desorption spectrometry. This technique is used for monitoring hydrogen uptake and release from different carbon electrocatalysts: 3D-graphene, single-walled carbon nanotube [...] Read more.
A comparative experimental study between advanced carbon nanostructured electrodes, in similar hydrogen uptake/desorption conditions, is investigated making use of the recent molecular beam-thermal desorption spectrometry. This technique is used for monitoring hydrogen uptake and release from different carbon electrocatalysts: 3D-graphene, single-walled carbon nanotube networks, multi-walled carbon nanotube networks, and carbon nanotube thread. It allows an accurate determination of the hydrogen mass absorbed in electrodes made from these materials, with significant enhancement in the signal-to-noise ratio for trace hydrogen avoiding recourse to ultra-high vacuum procedures. The hydrogen mass spectra account for the enhanced surface capability for hydrogen adsorption in the different types of electrode in similar uptake conditions, and confirm their enhanced hydrogen storage capacity, pointing to a great potential of carbon nanotube threads in replacing the heavier metals or metal alloys as hydrogen storage media. Full article
(This article belongs to the Special Issue Nanoalloy Electrocatalysts for Electrochemical Devices)
Show Figures

Figure 1

11 pages, 1321 KiB  
Article
Hydrogen Uptake and Release in Carbon Nanotube Electrocatalysts
by Rui Lobo, Jorge Ribeiro and Filipe Inok
Nanomaterials 2021, 11(4), 975; https://doi.org/10.3390/nano11040975 - 10 Apr 2021
Cited by 10 | Viewed by 1912
Abstract
The recent technique of molecular beam-thermal desorption spectrometry was used here for monitoring hydrogen uptake and release from carbon nanotube networks, after electrochemical hydrogen uptake. This way, an accurate determination of the hydrogen mass absorbed in electrodes made from those assemblies can be [...] Read more.
The recent technique of molecular beam-thermal desorption spectrometry was used here for monitoring hydrogen uptake and release from carbon nanotube networks, after electrochemical hydrogen uptake. This way, an accurate determination of the hydrogen mass absorbed in electrodes made from those assemblies can be achieved by significantly improving the signal-to-noise ratio. The hydrogen desorption mass spectra account for the enhanced surface capability for hydrogen adsorption in the electrodes and enable a comparison with the performance of a palladium electrode in similar conditions. A comparative study involving different carbon nanotube electrodes, in similar hydrogen uptake/desorption conditions, clearly confirmed the expectations about their enhanced hydrogen storage capacity and points to the great potential of carbon nanotube assemblies in replacing the heavier metal alloys as electrocatalysts. Full article
(This article belongs to the Special Issue Nanoalloy Electrocatalysts for Electrochemical Devices)
Show Figures

Figure 1

15 pages, 10398 KiB  
Article
Synthesis of Highly Active Pd@Cu–Pt/C Methanol Oxidation Electrocatalysts via Continuous, Co-Electroless Deposition
by Gregory L. Tate, Bahareh Alsadat Tavakoli Mehrabadi, Wen Xiong, Adam Kenvin and John R. Monnier
Nanomaterials 2021, 11(3), 793; https://doi.org/10.3390/nano11030793 - 19 Mar 2021
Cited by 5 | Viewed by 1868
Abstract
Controlled deposition of metals is essential for the creation of bimetallic catalysts having predictable composition and character. Continuous co-electroless deposition (co-ED) permits the creation of bimetallic catalysts with predictive control over composition. This method was applied to create a suite of Cu–Pt mixed-metal [...] Read more.
Controlled deposition of metals is essential for the creation of bimetallic catalysts having predictable composition and character. Continuous co-electroless deposition (co-ED) permits the creation of bimetallic catalysts with predictive control over composition. This method was applied to create a suite of Cu–Pt mixed-metal shell catalysts for use in methanol electrooxidation in direct methanol fuel cell applications (DMFCs). Enhanced performance of Cu–Pt compositions over Pt alone was predicted by existing computational studies in the literature. Experimental evidence from this study supports the bifunctional catalyst explanation for enhanced activity and confirms the optimum Cu:Pt ratio as Cu3Pt for this methanol electrooxidation. This ability to control the composition of a bimetallic shell can be extended to other systems where the ratio of two metals is critical for catalytic performance. Full article
(This article belongs to the Special Issue Nanoalloy Electrocatalysts for Electrochemical Devices)
Show Figures

Figure 1

12 pages, 3666 KiB  
Article
Carbon-Supported Mo2C for Oxygen Reduction Reaction Electrocatalysis
by Dušan Mladenović, Milica Vujković, Slavko Mentus, Diogo M. F. Santos, Raquel P. Rocha, Cesar A. C. Sequeira, Jose Luis Figueiredo and Biljana Šljukić
Nanomaterials 2020, 10(9), 1805; https://doi.org/10.3390/nano10091805 - 10 Sep 2020
Cited by 8 | Viewed by 3107
Abstract
Molybdenum carbide (Mo2C)-based electrocatalysts were prepared using two different carbon supports, commercial carbon nanotubes (CNTs) and synthesised carbon xerogel (CXG), to be studied from the point of view of both capacitive and electrocatalytic properties. Cation type (K+ or Na+ [...] Read more.
Molybdenum carbide (Mo2C)-based electrocatalysts were prepared using two different carbon supports, commercial carbon nanotubes (CNTs) and synthesised carbon xerogel (CXG), to be studied from the point of view of both capacitive and electrocatalytic properties. Cation type (K+ or Na+) in the alkaline electrolyte solution did not affect the rate of formation of the electrical double layer at a low scan rate of 10 mV s−1. Conversely, the different mobility of these cations through the electrolyte was found to be crucial for the rate of double-layer formation at higher scan rates. Molybdenum carbide supported on carbon xerogel (Mo2C/CXG) showed ca. 3 times higher double-layer capacity amounting to 75 mF cm−2 compared to molybdenum carbide supported on carbon nanotubes (Mo2C/CNT) with a value of 23 mF cm−2 due to having more than double the surface area size. The electrocatalytic properties of carbon-supported molybdenum carbides for the oxygen reduction reaction in alkaline media were evaluated using linear scan voltammetry with a rotating disk electrode. The studied materials demonstrated good electrocatalytic performance with Mo2C/CXG delivering higher current densities at more positive onset and half-wave potential. The number of electrons exchanged during oxygen reduction reaction (ORR) was calculated to be 3, suggesting a combination of four- and two-electron mechanism. Full article
(This article belongs to the Special Issue Nanoalloy Electrocatalysts for Electrochemical Devices)
Show Figures

Figure 1

Back to TopTop