Advanced Nanomaterials for Electrocatalysis: Synthesis, Characterization and Application

A special issue of Catalysts (ISSN 2073-4344). This special issue belongs to the section "Nanostructured Catalysts".

Deadline for manuscript submissions: closed (31 March 2023) | Viewed by 26609

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Guest Editor
Institute of Chemistry, Technology and Metallurgy (ICTM)- Department of Electrochemistry, University of Belgrade, Njegoševa 12, 11000 Belgrade, Serbia
Interests: electrocatalysis; surface electrochemistry; platinum group metals; in situ STM; phase AFM; oxygen reduction; hydrogen evolution; CO; methanol, and ethanol oxidation
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Special Issue Information

Dear Colleagues,

This Special Issue aims to attract authors seeking to present their up-to-date work on advanced nanomaterials for electrocatalysis. In such a wide-scale task, the focus is on a rational design and characterization of functional nanomaterials and the demonstration of the enhancement of their electrocatalytic performance as electrode materials for alternative energy devices (AED). In addition to the possible application of advanced nanomaterials, the fundamental aspects, including the investigation of model electrode nanomaterials and a theoretical basis of their electrocatalytic activity for the particular reaction, is also an important issue.

Among the new advanced nanomaterials, those consisting of platinum group metals as highly active electrocatalysts for AEDs and those of non-precious metals with equal or even higher activity are especially interesting. These include nanoparticles of single-crystalline structures, (multi)metallic nanoparticles, alloys with low noble metal content and various composite materials consisting of non-precious metals.

Because of the nanocatalyst-support interactions, the choice of the support material is of crucial importance. From the fundamental point of view, single-crystal supports offer a chance to examine the basis of heterogeneous catalysis, which involves electronic effect, the geometry of the surface-active sites, and their influence on the synergistic activity with nanocatalysts of well-defined structures for a range of electrochemical reactions. From the practical point of view, carbon-based supports offer a possibility for a rational design of low-cost nanoparticles either with a low content of noble metals down to a single atom or with non-precious metals. High electrocatalytic activity and long-term stability are the most decisive properties of such supported nanocatalysts for their use as electrodes contributing to the improved AED performance.

Besides, for this Special Issue, the electrochemical reactions of interest are (but not limited to): hydrogen evolution/oxidation, oxygen reduction/evolution, and CO, methanol and ethanol oxidation.

Prof. Dr. Svetlana B. Štrbac
Guest Editor

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Keywords

  • Synthesis and characterization of advanced nanomaterials 
  • Nanoparticles based on Pt-group metals 
  • Nanoparticles based on non-precious metals 
  • Pt-group metal supports 
  • Carbon based supports 
  • Hetrogeneous electrocatalysis 
  • Synergistic effect, electronic effect, surface-active sites 
  • Hydrogen evolution/oxidation 
  • Oxygen reduction/evolution 
  • CO, methanol and ethanol oxidation

Published Papers (11 papers)

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Research

16 pages, 3569 KiB  
Article
Redrawing HER Volcano with Interfacial Processes—The Role of Hydrogen Spillover in Boosting H2 Evolution in Alkaline Media
by Sanjin J. Gutić, Dino Metarapi, Aleksandar Z. Jovanović, Goitom K. Gebremariam, Ana S. Dobrota, Bojana Nedić Vasiljević and Igor A. Pašti
Catalysts 2023, 13(1), 89; https://doi.org/10.3390/catal13010089 - 01 Jan 2023
Cited by 3 | Viewed by 2261
Abstract
The requirements for the efficient replacement of fossil fuel, combined with the growing energy crisis, places focus on hydrogen production. Efficient and cost-effective electrocatalysts are needed for H2 production, and novel strategies for their discovery must be developed. Here, we utilized Kinetic [...] Read more.
The requirements for the efficient replacement of fossil fuel, combined with the growing energy crisis, places focus on hydrogen production. Efficient and cost-effective electrocatalysts are needed for H2 production, and novel strategies for their discovery must be developed. Here, we utilized Kinetic Monte Carlo (KMC) simulations to demonstrate that hydrogen evolution reaction (HER) can be boosted via hydrogen spillover to the support when the catalyst surface is largely covered by adsorbed hydrogen under operating conditions. Based on the insights from KMC, we synthesized a series of reduced graphene-oxide-supported catalysts and compared their activities towards HER in alkaline media with that of corresponding pure metals. For Ag, Au, and Zn, the support effect is negative, but for Pt, Pd, Fe, Co, and Ni, the presence of the support enhances HER activity. The HER volcano, constructed using calculated hydrogen binding energies and measured HER activities, shows a positive shift of the strong binding branch. This work demonstrates the possibilities of metal–support interface engineering for producing effective HER catalysts and provides general guidelines for choosing novel catalyst–support combinations for electrocatalytic hydrogen production. Full article
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10 pages, 2376 KiB  
Communication
Hydrogen Evolution Volcano(es)—From Acidic to Neutral and Alkaline Solutions
by Goitom K. Gebremariam, Aleksandar Z. Jovanović, Ana S. Dobrota, Natalia V. Skorodumova and Igor A. Pašti
Catalysts 2022, 12(12), 1541; https://doi.org/10.3390/catal12121541 - 30 Nov 2022
Cited by 5 | Viewed by 3156
Abstract
As the global energy crisis continues, efficient hydrogen production is one of the hottest topics these days. In this sense, establishing catalytic trends for hydrogen production is essential for choosing proper H2 generation technology and catalytic material. Volcano plots for hydrogen evolution [...] Read more.
As the global energy crisis continues, efficient hydrogen production is one of the hottest topics these days. In this sense, establishing catalytic trends for hydrogen production is essential for choosing proper H2 generation technology and catalytic material. Volcano plots for hydrogen evolution in acidic media are well-known, while a volcano plot in alkaline media was constructed ten years ago using theoretically calculated hydrogen binding energies. Here, for the first time, we show that the volcano-type relationships are largely maintained in a wide range of pH values, from acidic to neutral and alkaline solutions. We do this using theoretically calculated hydrogen binding energies on clean metallic surfaces and experimentally measured hydrogen evolution overpotentials. When metallic surfaces are exposed to high anodic potentials, hydrogen evolution can be boosted or significantly impeded, depending on the type of metal and the electrolyte in which the reaction occurs. Such effects are discussed here and can be used to properly tailor catalytic materials for hydrogen production via different water electrolysis technologies. Full article
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12 pages, 4574 KiB  
Article
NiFe Layered Double Hydroxide Electrocatalyst Prepared via an Electrochemical Deposition Method for the Oxygen Evolution Reaction
by Murugesan Praveen Kumar, Moorthy Sasikumar, Arunachalam Arulraj, Venugopalan Rajasudha, Govindhasamy Murugadoss, Manavalan Rajesh Kumar, Shaik Gouse Peera and Ramalinga Viswanathan Mangalaraja
Catalysts 2022, 12(11), 1470; https://doi.org/10.3390/catal12111470 - 18 Nov 2022
Cited by 11 | Viewed by 3511
Abstract
Herein, we aimed to obtain NiFe layered double hydroxide (LDH) with a controlled phase and surface morphology as a highly active and stable oxygen evolution catalyst via the electrochemical deposition method, which was thermodynamically stable for the oxygen evolution reaction (OER) in an [...] Read more.
Herein, we aimed to obtain NiFe layered double hydroxide (LDH) with a controlled phase and surface morphology as a highly active and stable oxygen evolution catalyst via the electrochemical deposition method, which was thermodynamically stable for the oxygen evolution reaction (OER) in an alkaline medium. The NiFe-LDH sample was analyzed by sophisticated instruments and tested as an electrocatalyst on Toray carbon (TC). The NiFe-LDH electrocatalyst showed an excellent performance with lower overpotential of 0.27 V at 35 mA cm−2 and higher density of 125 mA cm−2 for OER in the 1 M KOH electrolyte solution. Moreover, the prepared catalyst exhibited unpredictable long-time stability for 700 h. From our knowledge, NiFe-LDH is a robust highly stable electrocatalyst compared to the recent reports. Full article
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13 pages, 2631 KiB  
Article
Spark Ablation for the Fabrication of PEM Water Electrolysis Catalyst-Coated Membranes
by Foteini M. Sapountzi, Marek Lavorenti, Wilbert Vrijburg, Sofia Dimitriadou, Beata Tyburska-Pueschel, Peter Thüne, Hans Niemantsverdriet, Tobias V. Pfeiffer and Mihalis N. Tsampas
Catalysts 2022, 12(11), 1343; https://doi.org/10.3390/catal12111343 - 02 Nov 2022
Cited by 6 | Viewed by 3857
Abstract
Proton-exchange-membrane (PEM) electrolyzers represent a promising technology for sustainable hydrogen production, owing to their efficiency and load flexibility. However, the acidic nature of PEM demands the use of platinum-group metal-electrocatalysts. Apart from the associated high capital costs, the scarcity of Ir hinders the [...] Read more.
Proton-exchange-membrane (PEM) electrolyzers represent a promising technology for sustainable hydrogen production, owing to their efficiency and load flexibility. However, the acidic nature of PEM demands the use of platinum-group metal-electrocatalysts. Apart from the associated high capital costs, the scarcity of Ir hinders the large-scale implementation of the technology. Since low-cost replacements for Ir are not available at present, there is an urgent need to engineer catalyst-coated membranes (CCMs) with homogeneous catalyst layers at low Ir loadings. Efforts to realize this mainly rely on the development of advanced Ir nanostructures with maximized dispersion via wet chemistry routes. This study demonstrates the potential of an alternative vapor-based process, based on spark ablation and impaction, to fabricate efficient and durable Ir- and Pt-coated membranes. Our results indicate that spark-ablation CCMs can reduce the Ir demand by up to five times compared to commercial CCMs, without a compromise in activity. The durability of spark-ablation CCMs has been investigated by applying constant and dynamic load profiles for 150 h, indicating different degradation mechanisms for each case without major pitfalls. At constant load, an initial degradation in performance was observed during the first 30 h, but a stable degradation rate of 0.05 mV h−1 was sustained during the rest of the test. The present results, together with manufacturing aspects related to simplicity, costs and environmental footprint, suggest the high potential of spark ablation having practical applications in CCM manufacturing. Full article
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20 pages, 3467 KiB  
Article
Improved Oxygen Reduction on GC-Supported Large-Sized Pt Nanoparticles by the Addition of Pd
by Jelena Golubović, Lazar Rakočević, Dana Vasiljević Radović and Svetlana Štrbac
Catalysts 2022, 12(9), 968; https://doi.org/10.3390/catal12090968 - 29 Aug 2022
Cited by 3 | Viewed by 1627
Abstract
PdPt bimetallic nanoparticles on carbon-based supports functioning as advanced electrode materials have attracted attention due to their low content of noble metals and high catalytic activity for fuel cell reactions. Glassy carbon (GC)-supported Pt and PdPt nanoparticles, as promising catalysts for the oxygen [...] Read more.
PdPt bimetallic nanoparticles on carbon-based supports functioning as advanced electrode materials have attracted attention due to their low content of noble metals and high catalytic activity for fuel cell reactions. Glassy carbon (GC)-supported Pt and PdPt nanoparticles, as promising catalysts for the oxygen reduction reaction (ORR), were prepared by the electrochemical deposition of Pt and the subsequent spontaneous deposition of Pd. The obtained electrodes were examined using X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM), and electroanalytical techniques. An XPS analysis of the PdPt/GC with the highest ORR performance revealed that the stoichiometric ratio of Pd: Pt was 1:2, and that both Pt and Pd were partially oxidized. AFM images of PdPt2/GC showed the full coverage of GC with PdPt nanoparticles with sizes from 100–300 nm. The ORR activity of PdPt2/GC in an acid solution approached that of polycrystalline Pt (E1/2 = 0.825 V vs. RHE), while exceeding it in an alkaline solution (E1/2 = 0.841 V vs. RHE). The origin of the improved ORR on PdPt2/GC in an alkaline solution is ascribed to the presence of a higher amount of adsorbed OH species originating from both PtOH and PdOH that facilitated the 4e-reaction pathway. Full article
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8 pages, 1468 KiB  
Article
Controllable Construction of IrCo Nanoclusters and the Performance for Water Electrolysis
by Fangqin Mao, Xiaojie Zhao, Ying Chang and Jingchun Jia
Catalysts 2022, 12(8), 914; https://doi.org/10.3390/catal12080914 - 19 Aug 2022
Cited by 2 | Viewed by 1538 | Correction
Abstract
Finding a suitable catalyst is an important research direction in hydrogen (H2) production from water electrolysis. We report a synthetic method to obtain IrxCo/C clusters by polyol reduction. The catalyst is small in size and can be evenly distributed. [...] Read more.
Finding a suitable catalyst is an important research direction in hydrogen (H2) production from water electrolysis. We report a synthetic method to obtain IrxCo/C clusters by polyol reduction. The catalyst is small in size and can be evenly distributed. The Ir3Co/C cluster catalyst had very good activity under acidic conditions. The overpotential of the best-performing Ir3Co/C cluster for the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) is only 290 mV and 91 mV when 10 mA cm−2 and 100 mA cm−2. The catalyst performance may be improved because of the synergistic effect and the small size of the prepared catalyst, which accelerates proton transfer. This approach offers a strategy to reduce costs while improving catalytic activity. Full article
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11 pages, 2299 KiB  
Article
Preparation and Electrocatalytic Application of Copper- and Cobalt-Carbon Composites Based on Pyrolyzed Polymer
by Zainulla M. Muldakhmetov, Nina M. Ivanova, Yakha A. Vissurkhanova and Yelena A. Soboleva
Catalysts 2022, 12(8), 862; https://doi.org/10.3390/catal12080862 - 05 Aug 2022
Viewed by 1593
Abstract
Copper- and cobalt-containing carbon composites were prepared by pyrolysis of an aniline-formaldehyde polymer (AFP) doped with the metal oxides, followed by the reduction of metal cations in an electrochemical cell. AFP + metal oxide nanocomposites were synthesized by introducing a metal salt during [...] Read more.
Copper- and cobalt-containing carbon composites were prepared by pyrolysis of an aniline-formaldehyde polymer (AFP) doped with the metal oxides, followed by the reduction of metal cations in an electrochemical cell. AFP + metal oxide nanocomposites were synthesized by introducing a metal salt during the polycondensation of aniline with formaldehyde and by alkaline precipitation of metal oxides into the polymer matrix. The heat treatment was carried out at 400, 500 and 700 °C. Microscopic studies revealed the formation of CuO crystallites in the shape of "stars" on the heat-treated carbon material. The resulting composites were saturated with hydrogen in an electrochemical system, which was accompanied by the reduction of copper and cobalt cations, and the appearance of the metals in zero-valence state. The so-prepared Cu + copper oxides/C and Co + Co(OH)2/C composites were used as electrocatalysts in the electrohydrogenation of acetophenone (APh). Compared to the electrochemical reduction of APh on a copper cathode (without catalysts), an increase in the rate of this process (by 2–4 times) in the presence of the composites and an increase in the APh conversion with the selective formation of 1-phenylethanol were established. Full article
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16 pages, 2918 KiB  
Article
Insights into the Design of An Enzyme Free Sustainable Sensing Platform for Efavirenz
by Khethiwe Mthiyane, Gloria Ebube Uwaya, Maryam Amra Jordaan, Suvardhan Kanchi and Krishna Bisetty
Catalysts 2022, 12(8), 830; https://doi.org/10.3390/catal12080830 - 28 Jul 2022
Cited by 2 | Viewed by 1511
Abstract
In this study, a new hybrid sensor was developed using titanium oxide nanoparticles (TiO2-NPs) and nafion as an anchor agent on a glassy carbon electrode (GCE/TiO2-NPs-nafion) to detect efavirenz (EFV), an anti-HIV medication. TiO2-NPs was synthesized using [...] Read more.
In this study, a new hybrid sensor was developed using titanium oxide nanoparticles (TiO2-NPs) and nafion as an anchor agent on a glassy carbon electrode (GCE/TiO2-NPs-nafion) to detect efavirenz (EFV), an anti-HIV medication. TiO2-NPs was synthesized using Eucalyptus globulus leaf extract and characterized using ultraviolet–visible spectroscopy (UV–VIS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive spectroscopy (EDS). The electrochemical and sensing properties of the developed sensor for EFV were assessed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The current response of GCE/TiO2-NPs-nafion electrode towards the oxidation of EFV was greater compared to the bare GCE and GCE/TiO2-NPs electrodes. A linear dynamic range of 4.5 to 18.7 µM with 0.01 µM limit of detection was recorded on the electrode using differential pulse voltammetry (DPV). The electrochemical sensor demonstrated good selectivity and practicality for detecting EFV in pharmaceuticals (EFV drugs) with excellent recovery rates, ranging from 92.0–103.9%. The reactive sites of EFV have been analyzed using quantum chemical calculations based on density functional theory (DFT). Monte Carlo (MC) simulations revealed a strong electrostatic interaction on the substrate-adsorbate (GCE/TiO2-NPs-nafion-EFV) system. Results show good agreement between the MC computed adsorption energies and the experimental CV results for EFV. The stronger adsorption energy of nafion onto the GCE/TiO2-NPs substrate contributed to the catalytic role in the signal amplification for sensing of EFV. Our results provide an effective way to explore the design of new 2D materials for sensing of EFV, which is highly significant in medicinal and materials chemistry. Full article
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12 pages, 2036 KiB  
Article
Rare-Earth/Manganese Oxide-Based Composites Materials for Electrochemical Oxygen Reduction Reaction
by Stefan V. Panić, Marijana R. Pantović Pavlović, Miroslava M. Varničić, Vojin Tadić, Srećko Stopić, Bernd Friedrich and Miroslav M. Pavlović
Catalysts 2022, 12(6), 641; https://doi.org/10.3390/catal12060641 - 12 Jun 2022
Viewed by 1861
Abstract
The main objective of this research was a systematic development of advanced micro/nanostructured materials based on the most used metal-oxides for ORR and metal-oxides with an extremely low-loading of Pt for comparison. Hybrid composites compared were: MnO2, La2O3 [...] Read more.
The main objective of this research was a systematic development of advanced micro/nanostructured materials based on the most used metal-oxides for ORR and metal-oxides with an extremely low-loading of Pt for comparison. Hybrid composites compared were: MnO2, La2O3, mixed lanthanum manganese oxides (LMO), and mixed lanthanum manganese oxides with reduced platinum load (LMO-Pt). The influence of the reduced amount of noble metal, as well as single oxide activity toward ORR, was analyzed. The complete electrochemical performance of the hybrid materials has been performed by means of CV, LSV, and EIS. It was shown that all synthesized catalytic materials were ORR-active with noticeable reduction currents in O2 saturated 0.1 M KOH. The ORR behavior indicated that the La2O3 electrode has a different mechanism than the other tested electrode materials (MnO2, LMO, and LMO-Pt). The EIS results have revealed that the ORR reaction is of a mixed character, being electrochemically and diffusion controlled. Even more, diffusion is of mixed character due to transport of O2 molecules and the chemical reaction of oxygen reduction. O2 diffusion was shown to be the dominant process for MnO2, LMO, and LMO-Pt electrolytic materials, while chemical reaction is the dominant process for La2O3 electrolytic materials. Full article
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13 pages, 3380 KiB  
Article
PtAu Nanoparticles Supported by Reduced Graphene Oxide as a Highly Active Catalyst for Hydrogen Evolution
by Lazar Rakočević, Ivana Stojković Simatović, Aleksandar Maksić, Vladimir Rajić, Svetlana Štrbac and Irina Srejić
Catalysts 2022, 12(1), 43; https://doi.org/10.3390/catal12010043 - 31 Dec 2021
Cited by 14 | Viewed by 2839
Abstract
PtAu nanoparticles spontaneously deposited on graphene support, PtAu/rGO, have shown remarkably high catalytic activity for hydrogen evolution reaction (HER) in sulfuric acid solution. SEM images of the PtAu/rGO electrode surface showed that Pt nanoparticles that are non-uniform in size occupy both the edges [...] Read more.
PtAu nanoparticles spontaneously deposited on graphene support, PtAu/rGO, have shown remarkably high catalytic activity for hydrogen evolution reaction (HER) in sulfuric acid solution. SEM images of the PtAu/rGO electrode surface showed that Pt nanoparticles that are non-uniform in size occupy both the edges of previously deposited uniform Au nanoparticles and the edges of graphene support. XPS analysis showed that the atomic percentages of Au and Pt in PtAu/rGO were 0.6% and 0.3%, respectively. The atomic percentage of Au alone on previously prepared Au/rGO was 0.7%. Outstanding HER activity was achieved for the PtAu/rGO electrode, showing the initial potential close to the equilibrium potential for HER and a low Tafel slope of −38 mV/dec. This was confirmed by electrochemical impedance spectroscopy. The chronoamperometric measurement performed for 40 min for hydrogen evolution at a constant potential indicated good stability and durability of the PtAu/rGO electrode. Full article
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24 pages, 3999 KiB  
Article
The Electrochemical Behaviour of Quaternary Amine-Based Room-Temperature Ionic Liquid N4111(TFSI)
by Jaanus Kruusma, Arvo Tõnisoo, Rainer Pärna, Thomas Thomberg, Mati Kook, Tavo Romann, Vambola Kisand and Enn Lust
Catalysts 2021, 11(11), 1315; https://doi.org/10.3390/catal11111315 - 30 Oct 2021
Cited by 2 | Viewed by 1584
Abstract
In this study, we used the in situ X-ray photoelectron spectroscopy (XPS), in situ mass spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy methods, for the first time, in a detailed exploration of the electrochemical behaviour of a quaternary amine cation-based room-temperature ionic liquid, [...] Read more.
In this study, we used the in situ X-ray photoelectron spectroscopy (XPS), in situ mass spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy methods, for the first time, in a detailed exploration of the electrochemical behaviour of a quaternary amine cation-based room-temperature ionic liquid, butyl-trimethyl-ammonium bis(trifluoromethylsulfonyl)imide (N4111(TFSI)), at the negatively and positively polarised molybdenum carbide-derived micro-mesoporous carbon (mmp-C(Mo2C)) electrodes that can be used as high surface area supporting material for electrocatalysts. The shapes of the C 1s, N 1s, O 1s, F 1s and S 2p XPS spectra were stable for N4111(TFSI) within a very wide potential range. The XPS data indicated the non-specific adsorption character of the cations and anions in the potential range from −2.00 V to 0.00 V. Thus, this region can be used for the detailed analysis of catalytic reaction mechanisms. We observed strong adsorption from 0.00 V to 1.80 V, and at E > 1.80 V, very strong adsorption of the N4111(TFSI) at the mmp-C(Mo2C) took place. At more negative potentials than −2.00 V, the formation of a surface layer containing both N4111+ cations and TFSI anions was established with the formation of various gaseous compounds. Collected data indicated the electrochemical instability of the N4111+ cation at E < −2.00 V. Full article
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