Special Issue "Advances in Electrocatalysis"

A special issue of Catalysts (ISSN 2073-4344).

Deadline for manuscript submissions: closed (31 October 2017)

Special Issue Editor

Guest Editor
Prof. Dr. Luísa Margarida Martins

1. ISEL—Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emídio Navarro 1, 1959-007 Lisboa, Portugal
2. Coordination Chemistry and Catalysis (CCC), CQE—Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
Website | E-Mail
Interests: coordination and sustainable chemistry; homogeneous and supported catalysis; nanomaterials and nanocatalysis; electrochemistry

Special Issue Information

Dear Colleagues,

Electrocatalysis, a type of catalysis that results in the modification of the rate of an electrochemical reaction occurring on an electrode surface, is an indispensable working resource for electrochemists, chemical engineers, biochemical, surface, and materials scientists.

This special field of Electrochemistry has gained notable growth, mainly driven from the urgent need for advanced catalytic materials in electrochemical energy technologies. Progress in this, and other, areas continues to be of primary relevance for the development of highly-efficient and environmentally-benign industrial electrochemical processes.

This Special Issue is aimed at covering emerging and promising strategies for the development of sustainable electrocatalytic processes, focusing on aspects that drive present and future research. Authors with expertise in this topic are cordially invited to submit their manuscripts to Catalysts. Significant full papers and review articles are welcome.

Professor Luísa Margarida Martins
Guest Editor

Related Meeting:

22nd Meeting of the Portuguese Society of Electrochemistry (XXII SPE MEETING)
19–22 June 2017
Ponta Delgada, Azores
http://www.spe2017.com/

Keywords

  • Electrocatalysis for Energy
  • Electrocatalytic (Nano)Materials
  • Electrocatalytic Techniques and Methodologies
  • Electrooxidation of Small Organic Molecules
  • Hydrogen Evolution Reaction
  • Hydrogen Oxidation Reaction
  • Hydrogen Storage
  • Oxygen Evolution Reaction
  • Oxygen Reduction Reaction
  • Nanotechnology in Electrocatalysis
  • Synthetic Electrocatalysis
  • Water-based Electrochemical Devices
  • Water Management

Published Papers (12 papers)

View options order results:
result details:
Displaying articles 1-12
Export citation of selected articles as:

Research

Open AccessArticle Preparation of Manganese Lignosulfonate and Its Application as the Precursor of Nanostructured MnOx for Oxidative Electrocatalysis
Catalysts 2017, 7(12), 392; doi:10.3390/catal7120392 (registering DOI)
Received: 6 November 2017 / Revised: 11 December 2017 / Accepted: 13 December 2017 / Published: 15 December 2017
PDF Full-text (4717 KB) | HTML Full-text | XML Full-text
Abstract
The synthesis of manganese lignosulfonates by a two-step method has been reported. It was based on the conversion of technical sodium derivative of lignosulfonate to its hydrogen form i.e., lignosulfonic acid and its further reaction with manganese hydroxide. The obtained product was electroactive,
[...] Read more.
The synthesis of manganese lignosulfonates by a two-step method has been reported. It was based on the conversion of technical sodium derivative of lignosulfonate to its hydrogen form i.e., lignosulfonic acid and its further reaction with manganese hydroxide. The obtained product was electroactive, and could be applied as the precursor of electroactive manganese oxide. The product showed a reversible redox activity in the potential range of 0 to 1 V vs. an Ag/AgCl reference electrode. The electroactivity of the obtained product can be tentatively assigned to the redox activity of both the electrodeposited MnOx and the presence of lignosulfonate-derived quinones since the energy dispersive spectroscopy (EDS) confirmed the presence of organic matter in the deposit. It also showed substantial electrocatalytic activity towards the anodic oxidation of hydrogen peroxide. This suggests that manganese lignosulfonates could be a valuable compound for the electrochemical preparation of electroactive layers that are suitable in the development of electrochemical sensors. Full article
(This article belongs to the Special Issue Advances in Electrocatalysis)
Figures

Figure 1

Open AccessArticle Characteristics of NixFe1−xOy Electrocatalyst on Hematite as Photoanode for Solar Hydrogen Production
Catalysts 2017, 7(11), 350; doi:10.3390/catal7110350
Received: 20 September 2017 / Revised: 15 November 2017 / Accepted: 17 November 2017 / Published: 20 November 2017
PDF Full-text (1220 KB) | HTML Full-text | XML Full-text
Abstract
The use of hematite as the photoanode for photoelectrochemical hydrogen production by solar energy has been actively studied due to its abundance, stability, and adequate optical properties. Deposition of an electrocatalyst overlayer on the hematite may increase kinetics and lower the onset potential
[...] Read more.
The use of hematite as the photoanode for photoelectrochemical hydrogen production by solar energy has been actively studied due to its abundance, stability, and adequate optical properties. Deposition of an electrocatalyst overlayer on the hematite may increase kinetics and lower the onset potential for water splitting. NixFe1−xOy is one of the most effective electrocatalysts reported for this purpose. However, the condition and results of the previous reports vary significantly, and a comprehensive model for NixFe1−xOy/hematite is lacking. Here, we report a simple and novel chemical bath deposition method for depositing low-onset-potential NixFe1−xOy electrocatalyst on hematite. With a Ni percentage of 80% and an immersion time of 2 min, the as-prepared NixFe1−xOy overlayer raised the photovoltage from 0.2 V to 0.7 V, leading to a cathodic shift of the onset potential by 400 mV, while maintaining the same level of current density. The dependence of the electrochemical and photoelectrochemical characteristics of the photoanode on the condition of the electrocatalyst was studied systematically and explained based on energy level diagrams and kinetics. Full article
(This article belongs to the Special Issue Advances in Electrocatalysis)
Figures

Figure 1

Open AccessArticle Efficient Degradation of Refractory Organics Using Sulfate Radicals Generated Directly from WO3 Photoelectrode and the Catalytic Reaction of Sulfate
Catalysts 2017, 7(11), 346; doi:10.3390/catal7110346
Received: 12 October 2017 / Revised: 10 November 2017 / Accepted: 12 November 2017 / Published: 17 November 2017
PDF Full-text (7766 KB) | HTML Full-text | XML Full-text
Abstract
An environment-friendly method of efficiently degrading refractory organics using SO4• generated directly from a WO3 photoelectrode and a catalytic reaction of sulfate was proposed, in which the cycling process of SO42− → SO4• →
[...] Read more.
An environment-friendly method of efficiently degrading refractory organics using SO4• generated directly from a WO3 photoelectrode and a catalytic reaction of sulfate was proposed, in which the cycling process of SO42− → SO4• → SO42− was achieved in the treatment of organic pollutants without any other activator and without the continuous addition of sulfate. The results show that the removal efficiency for a typical refractory organics of methyl orange (MO) with 5 mg/L was up to 95% within 80 min, and merely 3% by photolysis and 19% by photocatalysis, respectively, under similar conditions. The rate constant for the disposal of MO at pH 2, in which SO4• instead of HO• is the main oxidizer confirmed by radical scavenger experiment, is up to 5.21 × 10−4 s−1, which was ~6.6 times that (7.89 × 10−5 s−1) under neutral condition, in which HO• is the main oxidizer. The concentration of active persulfate (S2O82−, SO52−, and SO4•) species at pH 2 was up to 0.38 mM, which was ~16-fold as much as that (0.023 mM) in neutral conditions. The method provides a new approach for the treatment and resource utilization of sulfate wastewater. Full article
(This article belongs to the Special Issue Advances in Electrocatalysis)
Figures

Open AccessArticle Terpyridine-Containing Imine-Rich Graphene for the Oxygen Reduction Reaction
Catalysts 2017, 7(11), 338; doi:10.3390/catal7110338
Received: 18 October 2017 / Revised: 6 November 2017 / Accepted: 7 November 2017 / Published: 10 November 2017
PDF Full-text (3500 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
We report a facile synthetic method for the preparation of a terpyridine-containing imine-rich graphene (IrGO-Tpy) using an acid-catalyzed dehydration reaction between graphene oxide (GO) and 4′-(aminophenyl)-2,2′:6′2″-terpyridine. Owing to the presence of terpyridine ligands, cobalt ions (Co2+) were readily incorporated into the
[...] Read more.
We report a facile synthetic method for the preparation of a terpyridine-containing imine-rich graphene (IrGO-Tpy) using an acid-catalyzed dehydration reaction between graphene oxide (GO) and 4′-(aminophenyl)-2,2′:6′2″-terpyridine. Owing to the presence of terpyridine ligands, cobalt ions (Co2+) were readily incorporated into the IrGO-Tpy structures, affording a metal complex, denoted IrGo-Tpy-Co. Cyclic voltammetry and linear sweep voltammetry measurements confirm the noticeable oxygen reduction reaction (ORR) activities of the IrGo-Tpy and IrGo-Tpy-Co electroacatalysts in alkaline electrolytes, along with the additional merits of high selectivity, excellent long-term durability, and good resistance to methanol crossover. In addition, a remarkable improvement in the ORR performance was observed for IrGO-Tpy-Co compared with that of IrGo-Tpy, arising from the significant contribution of the cobalt-terpyridine complex in facilitating the ORR process. Full article
(This article belongs to the Special Issue Advances in Electrocatalysis)
Figures

Open AccessArticle Electrocarboxylation of Dichlorobenzenes on a Silver Electrode in DMF
Catalysts 2017, 7(9), 274; doi:10.3390/catal7090274
Received: 25 August 2017 / Revised: 12 September 2017 / Accepted: 13 September 2017 / Published: 15 September 2017
PDF Full-text (1320 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Carbon dioxide (CO2) is the largest contributor to the greenhouse effect, and fixing and using this greenhouse gas in a facile manner is crucial. This work investigates the electrocarboxylation of dichlorobenzenes with the atmospheric pressure of CO2 in an undivided
[...] Read more.
Carbon dioxide (CO2) is the largest contributor to the greenhouse effect, and fixing and using this greenhouse gas in a facile manner is crucial. This work investigates the electrocarboxylation of dichlorobenzenes with the atmospheric pressure of CO2 in an undivided cell with an Ag cathode and an Mg sacrificial anode. The corresponding carboxylic acids and their derivatives, which are important industrial and fine chemicals, are obtained. To deeply understand this reaction, we investigate the influence of various reaction conditions, such as supporting electrolyte, current density, electric charge, and reaction temperature, on the electrocarboxylation yield by using 1,4-dichlorobenzene as the model compound. The electrochemical behavior of dichlorobenzenes is studied through cyclic voltammetry. The relation among the distinct electronic effects of dichlorobenzenes, the electrochemical characteristics of their reduction, and the distribution law of target products is also established. Full article
(This article belongs to the Special Issue Advances in Electrocatalysis)
Figures

Open AccessArticle SnSx (x = 1, 2) Nanocrystals as Effective Catalysts for Photoelectrochemical Water Splitting
Catalysts 2017, 7(9), 252; doi:10.3390/catal7090252
Received: 1 August 2017 / Revised: 21 August 2017 / Accepted: 24 August 2017 / Published: 25 August 2017
PDF Full-text (3854 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Two-dimensional SnSx (x = 1, 2) nanocrystals are attractive catalysts for photoelectrochemical water splitting as their components are earth abundant and environmentally friendly. We have fabricated SnS thin-film photoelectrodes by spin coating mixed-phase SnS nanocrystals synthesized via a hot-injection technique on glass/Cr/Au
[...] Read more.
Two-dimensional SnSx (x = 1, 2) nanocrystals are attractive catalysts for photoelectrochemical water splitting as their components are earth abundant and environmentally friendly. We have fabricated SnS thin-film photoelectrodes by spin coating mixed-phase SnS nanocrystals synthesized via a hot-injection technique on glass/Cr/Au substrates. The obtained SnS thin films can be transformed into SnS2 by introducing structural phase changes via a facile low-vacuum annealing protocol in the presence of sulfur. This sulfurization process enables the insertion of sulfur atoms between layers of SnS and results in the generation of shallow donors that alter the mechanism for water splitting. The SnS2 thin films are used as stable photocatalysts to drive the oxygen evolution reaction, and the light-current density of 0.195 mA/cm2 at 0.8 V vs. Ag/AgCl can be achieved due to the high carrier density, lower charge transfer resistance, and a suitable reaction band position. Based on a combination of UV-Vis spectroscopy (ultraviolet and visible spectroscopy), cyclic voltammetry and Mott–Schottky analysis, the band positions and band gaps of SnS and SnS2 relative to the electrolyte are determined and a detailed mechanism for water splitting is presented. Our results demonstrate the potential of layered tin sulfide compounds as promising photocatalysts for efficient and large-scale water splitting. Full article
(This article belongs to the Special Issue Advances in Electrocatalysis)
Figures

Open AccessArticle Ethanol Oxidation Reaction on Tandem Pt/Rh/SnOx Catalyst
Catalysts 2017, 7(9), 246; doi:10.3390/catal7090246
Received: 18 July 2017 / Revised: 12 August 2017 / Accepted: 20 August 2017 / Published: 24 August 2017
PDF Full-text (3536 KB) | HTML Full-text | XML Full-text
Abstract
To elucidate the atomic arrangement of a Pt-Rh-Sn ternary catalyst with a high catalytic activity for ethanol oxidation reaction (EOR) and high CO2 selectivity, we prepared a tandem Pt/Rh/SnOx, in which a Rh adlayer was deposited on a Pt substrate
[...] Read more.
To elucidate the atomic arrangement of a Pt-Rh-Sn ternary catalyst with a high catalytic activity for ethanol oxidation reaction (EOR) and high CO2 selectivity, we prepared a tandem Pt/Rh/SnOx, in which a Rh adlayer was deposited on a Pt substrate (Rh coverage: 0.28), followed by depositing several layers of SnOx only on the Rh surface (Sn coverage: 0.07). For reference, Sn was randomly deposited on the Rh-modified Pt (Pt/Rh) electrode whose Rh and Sn coverages were 0.22 and 0.36 (random Pt/Rh/SnOx). X-ray photoelectron spectroscopy demonstrated that Pt and Rh were metallic, and Sn was largely oxidized. Both Pt/Rh/SnOx electrodes were less positive in onset potential of EOR current density and higher in EOR current density than Pt and Rh/Pt electrodes. In situ infrared reflection-absorption spectroscopy demonstrated that the tandem Pt/Rh/SnOx electrode did not produce acetic acid, but produced CO2 in contrast to the random Pt/Rh/SnOx, suggesting that a tandem arrangement of Pt, Rh and SnOx, in which the Pt and SnOx sites were separated by the Rh sites, was effective for selective CO2 production. In the electrostatic electrolysis at 0.5 V vs. RHE, the tandem Pt/Rh/SnOx electrode exhibited higher EOR current density than the Pt and Pt/Rh electrodes after 1.5 h. Full article
(This article belongs to the Special Issue Advances in Electrocatalysis)
Figures

Open AccessArticle The Differentiating Polarization Curve Technique for the Tafel Parameter Estimation
Catalysts 2017, 7(8), 239; doi:10.3390/catal7080239
Received: 21 July 2017 / Revised: 11 August 2017 / Accepted: 14 August 2017 / Published: 17 August 2017
PDF Full-text (5821 KB) | HTML Full-text | XML Full-text
Abstract
An experimentally obtained polarization curve for the hydrogen evolution reaction on silver in a 0.5 mol dm−3 solution was investigated using an electrochemical curve technique named the differential polarization method (DPM). The exchange current density estimated by the Tafel extrapolation method (TEM)
[...] Read more.
An experimentally obtained polarization curve for the hydrogen evolution reaction on silver in a 0.5 mol dm−3 solution was investigated using an electrochemical curve technique named the differential polarization method (DPM). The exchange current density estimated by the Tafel extrapolation method (TEM) and the DPM were compared and assessed from points of simple and more accurate handling. It is shown that the DPM has two advantages: (1) proper reading of the Tafel slope region and (2) elimination of the undesirable physical factors such as oxide film and solution resistance. Full article
(This article belongs to the Special Issue Advances in Electrocatalysis)
Figures

Figure 1

Open AccessArticle Electroreduction of CO2 into Ethanol over an Active Catalyst: Copper Supported on Titania
Catalysts 2017, 7(7), 220; doi:10.3390/catal7070220
Received: 15 June 2017 / Revised: 15 July 2017 / Accepted: 18 July 2017 / Published: 20 July 2017
Cited by 1 | PDF Full-text (2722 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A simple, inexpensive, and novel method was used to prepare electrocatalysts from Cu supported on titanium dioxide (Cu/TiO2). XRD, SEM, and TEM characterizations confirmed different loadings of Cu nanoparticles (NPs) on TiO2. Cyclic voltammetry tests indicated that Cu/TiO2
[...] Read more.
A simple, inexpensive, and novel method was used to prepare electrocatalysts from Cu supported on titanium dioxide (Cu/TiO2). XRD, SEM, and TEM characterizations confirmed different loadings of Cu nanoparticles (NPs) on TiO2. Cyclic voltammetry tests indicated that Cu/TiO2 exhibited lower overpotential for CO2 reduction than that of Cu NPs. Moreover, 40 wt % Cu/TiO2 exhibited the highest faradaic efficiency for ethanol (FEethanol) of 27.4%, which is approximately 10-fold higher than that for Cu NPs (FEethanol = 2.7%). The 40 wt % Cu/TiO2 electrocatalyst exhibits a stable current density of 8.66 mA/cm2 over a 25 h stability test. The high efficiency towards CO2 electroreduction to ethanol may be attributed to the synergistic effect of Cu and TiO2 NPs. This work highlights the importance of compositional effect of NPs on their catalytic activities and provides a strategy for designing efficient catalysts for CO2 electroreduction in the future. Full article
(This article belongs to the Special Issue Advances in Electrocatalysis)
Figures

Open AccessArticle Newly Designed Ternary Metallic PtPdBi Hollow Catalyst with High Performance for Methanol and Ethanol Oxidation
Catalysts 2017, 7(7), 208; doi:10.3390/catal7070208
Received: 13 June 2017 / Revised: 2 July 2017 / Accepted: 6 July 2017 / Published: 10 July 2017
PDF Full-text (1380 KB) | HTML Full-text | XML Full-text
Abstract
This paper reported the fabrication of ternary metallic PtPdBi hollow nanocatalyst through a facile, one-pot, wet-chemical method by adopting sodium borohydride and polyvinylpyrrolidone as reducing agent and surfactant directing agent, respectively. The hollow structure offers novel morphology and large surface areas, which are
[...] Read more.
This paper reported the fabrication of ternary metallic PtPdBi hollow nanocatalyst through a facile, one-pot, wet-chemical method by adopting sodium borohydride and polyvinylpyrrolidone as reducing agent and surfactant directing agent, respectively. The hollow structure offers novel morphology and large surface areas, which are conducive to enhancing the electrocatalytic activity. The electrocatalytic properties of hollow PtPdBi nanocatalyst were investigated systematically in alkaline media through cyclic voltammetry and the as-prepared PtPdBi nanocatalyst displays greatly enhanced electrocatalytic activities towards methanol and ethanol oxidation. The calculated mass activities of PtPdBi electrocatalyst are 2.133 A mgPtPd−1 for methanol oxidation reaction and 5.256 A mgPtPd−1 for ethanol oxidation reaction, which are much better than that of commercial Pt/C and commercial Pd/C. The as-prepared hollow nanocatalyst may be a potential promising electrocatalyst in fuel cells and also may be extended to the applications of other desirable functions. Full article
(This article belongs to the Special Issue Advances in Electrocatalysis)
Figures

Open AccessArticle Ordered PtSn/C Electrocatalyst: A High Performance Material for the Borohydride Electrooxidation Reaction
Catalysts 2017, 7(7), 198; doi:10.3390/catal7070198
Received: 13 March 2017 / Revised: 2 June 2017 / Accepted: 4 June 2017 / Published: 29 June 2017
PDF Full-text (1180 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
This work used a rotating disc electrode and quasi-steady state polarization curves to investigate the sodium borohydride electrooxidation of ordered intermetallic PtSn/C in alkaline solution. Under similar experimental conditions, PtSn/C proved to be a better electrocatalyst than Pt in an overall process that
[...] Read more.
This work used a rotating disc electrode and quasi-steady state polarization curves to investigate the sodium borohydride electrooxidation of ordered intermetallic PtSn/C in alkaline solution. Under similar experimental conditions, PtSn/C proved to be a better electrocatalyst than Pt in an overall process that involved eight electrons. Assays performed in the presence of thiourea and S2− species evidenced that a chemical hydrolysis step took place, followed by electrochemical oxidation of the generated H2. The results presented herein suggest that PtSn/C constitutes a promising electrode material for application in alkaline borohydride fuel cell. Full article
(This article belongs to the Special Issue Advances in Electrocatalysis)
Figures

Figure 1

Open AccessArticle The Effects of CeO2 Nanorods and CeO2 Nanoflakes on Ni–S Alloys in Hydrogen Evolution Reactions in Alkaline Solutions
Catalysts 2017, 7(7), 197; doi:10.3390/catal7070197
Received: 8 May 2017 / Revised: 15 June 2017 / Accepted: 16 June 2017 / Published: 27 June 2017
PDF Full-text (3334 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Composite coatings synthesized by different morphologies of CeO2 in supergravity devices are highly active in hydrogen evolution reactions (HERs). By adding CeO2 nanoflakes (CeO2 Nf) or CeO2 nanorods (CeO2 Nr), the change in the microstructures of composites becomes quite distinct. Moreover, most Ni–S
[...] Read more.
Composite coatings synthesized by different morphologies of CeO2 in supergravity devices are highly active in hydrogen evolution reactions (HERs). By adding CeO2 nanoflakes (CeO2 Nf) or CeO2 nanorods (CeO2 Nr), the change in the microstructures of composites becomes quite distinct. Moreover, most Ni–S alloys are attached on the surface of CeO2 and roughen it compare with pure CeO2. In order to make the expression more concise, this paper uses M instead of Ni–S. At a current density of 10 mA/cm2, overpotentials of Ni–S/CeO2 Nr (M–CeO2 Nr) and Ni–S/CeO2 Nf (M–CeO2 Nf) are 200 mV and 180 mV respectively, which is lower than that of Ni–S (M-0) coating (240 mV). The exchange current density (j0) values of M–CeO2 Nf and M–CeO2 Nr are 7.48 mA/cm2 and 7.40 mA/cm2, respectively, which are higher than that of M-0 (6.39 mA/cm2). Meanwhile, double-layer capacitances (Cdl) values of M–CeO2 Nf (6.4 mF/cm2) and M–CeO2 Nr (6 mF/cm2) are 21.3 times and 20 times of M-0 (0.3 mF/cm2), respectively Full article
(This article belongs to the Special Issue Advances in Electrocatalysis)
Figures

Figure 1

Back to Top