Polyoxometallate-assisted integration of nanostructures of Au and ZrO 2 to form supports for electrocatalytic PtRu nanoparticles: enhancement of their activity toward oxidation of ethanol

Rutkowska, Iwona A.; Żołądek, Sylwia; Kulesza, Paweł J.

doi:10.1016/j.electacta.2014.12.098

Cited by 15 publications

(27 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4, 5 and 6) and literature reports, 22,24,[27][28][29][63][64][65][66] it can be rationalized that, at the potential as low 0.34 V, electrooxidation of ethanol at PtRu-based catalysts proceeds through simple dehydrogenation to acetaldehyde. 58,59 In other words, the reaction involves two-electrons, and no other parallel pathways (neither oxidation to acetic acid nor to carbon dioxide) are expected under potentials below 0.35 V. To comment on the dynamics of this reaction, we have performed diagnostic chronoamperometric experiments as for Fig.…”

Section: Microscopic Characterization Of Tio 2 Cnts and Cnt-supportedmentioning

confidence: 99%

“…2B and 2C reflect typical electrochemical behavior of PtRu nanoparticles (deposited on glassy carbon electrode) recorded in acid medium. 28,29 Obviously, addition of CNTs as carriers for dispersed PtRu has led to some increase of capacitive-type background currents. It is apparent upon comparison of voltammetric curves of Figs.…”

Section: Microscopic Characterization Of Tio 2 Cnts and Cnt-supportedmentioning

confidence: 99%

“…[26][27][28][29] Any specific interactions between catalytic sites and the metal oxide matrix as well as the system's interfacial ion and electron transfer processes would be influenced by the distribution of electronic states within the oxide.…”

mentioning

confidence: 99%

“…9 Representative examples include studies with use of titanium(IV) oxide, [19][20][21][22] tungsten(VI) oxide [22][23][24][25] and zirconium(IV) oxide. [26][27][28][29] Any specific interactions between catalytic sites and the metal oxide matrix as well as the system's interfacial ion and electron transfer processes would be influenced by the distribution of electronic states within the oxide. 30 In aqueous acid media, the oxides are covered by hydroxyl groups 31 facilitating proton mobility and influencing the system's catalytic activity during electrooxidations.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Electroanalysis of Ethanol Oxidation and Reactivity of Platinum-Ruthenium Catalysts Supported onto Nanostructured Titanium Dioxide Matrices

Rutkowska

Kulesza

2015

J. Electrochem. Soc.

Self Cite

View full text Add to dashboard Cite

This study concentrates on the development of catalytic materials capable of enhancing oxidation of ethanol particularly at low potentials, i.e. at conditions resembling operation of anodes in low temperature fuel cells. Indeed, the ethanol oxidation currents measured under voltammetric and chronoamperometric conditions have been significantly increased following dispersing bimetallic PtRu nanoparticle (∼4 nm) catalysts over TiO 2 (80% anatase, 20% rutile) nanostructures (∼20-30 nm) supported onto multi-walled carbon nanotubes. The improvement in activity is attributed not only to better dispersion of PtRu centers (some increase of active surface area) or improved (carbon-nanotube-assisted) propagation of electrons at the catalytic interface but also to the presence of hydroxyl groups and high mobility of protons at neighboring (to PtRu) TiO 2 . Further, specific interactions between TiO 2 and Pt or Ru metallic components are feasible. Importance of addition of TiO 2 is also evident from kinetic analysis based on measurements of steady-state currents at different concentrations. Ethanol is a renewable low-cost biofuel acting not only during simple combustion but also under electrochemical oxidation (catalytic) conditions thus becoming a reactant of potential importance to the technology of low-temperature direct-alcohol fuel cells. In principle, ethanol has high energy density, 29.7 kJ g −1 (23.3 kJ cm −3 ), moderate toxicity, and it exists as liquid at room temperature what allows its easier handling, transportation and storage. Although ethanol (C 2 H 5 OH) is a model di-carbonic (ethyl) alcohol, its electrooxidation is much more complex when compared to the oxidation mechanism of mono-carbonic (methyl) alcohol. Indeed, methanol (CH 3 OH) can be readily oxidized to the final product, CO 2 , through the transfer of six electrons.1 Due to high toxicity of methanol and its capability to undergo crossover through proton-conducting membranes to the cathodic compartments of fuel cells, intense research involving other small organic molecules including ethanol 2-10 has been recently pursued.If electrooxidation of ethanol proceeded ideally to carbon dioxide, the reaction would involve twelve electrons; under such conditions, the fuel cell (with an oxygen cathode) would theoretically produce the open circuit potential of 1.14 V. But complete oxidation of ethanol under electrochemical conditions is a complex reaction because the process would require cleavage of the strong C-C bond in the C 2 H 5 OH molecule.11-13 Consequently, the reaction rate is rather slow at ambient conditions, and typically acetaldehyde (two-electron oxidation) or acetic acid (four-electron oxidation) are formed during electrooxidations at common Pt-based (e.g. PtRu or PtSn) catalytic systems.Despite the unique ability of metallic platinum catalysts to break C-C bond in the ethanol molecule, Pt alloys with Ru or Sn tend to produce higher electrocatalytic currents than platinum itself. 14,15 Practical utility of bare Pt is largely limited by blocki...

show abstract

Section: Microscopic Characterization Of Tio 2 Cnts and Cnt-supportedmentioning

confidence: 99%

Section: Microscopic Characterization Of Tio 2 Cnts and Cnt-supportedmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Electroanalysis of Ethanol Oxidation and Reactivity of Platinum-Ruthenium Catalysts Supported onto Nanostructured Titanium Dioxide Matrices

Rutkowska

Kulesza

2015

J. Electrochem. Soc.

Self Cite

View full text Add to dashboard Cite

show abstract

“…[17][18][19] It has been reported that phosphomolybdic acid (H 3 PMo 12 O 48 , PMo 12 ) can form an anionic monolayer on the carbon materials, 20 PMo 12 -functionalization could exfoliate the stacked graphene sheets into individual ones through their electrostatic repulsion. The negatively charged PMo 12 on graphene sheets (GSs) may facilitate a uniform deposition of positively charged molecules such as conductive polymers and ionic liquids, which reducing the interfacial resistance.…”

mentioning

confidence: 99%

Self-Assembled Ionic Liquid-Phosphomolybdic Acid/Reduced Graphene Oxide Composite Modified Electrode for Sensitive Determination of Dopamine

Zhao

Zhang

Xia

et al. 2016

ECS J. Solid State Sci. Technol.

View full text Add to dashboard Cite

A novel reduced graphene oxide (RGO) coated glassy carbon electrode (IL-PMo 12 /RGO/GCE) modified with ionic liquid (IL, [BMIM][BF 4 ]) and phosphomolybdic acid (PMo 12, H 3 PMo 12 O 48 ) was fabricated via electrostatic self-assembling. The phosphomolybdic acid anionic monolayer could electrostatically adsorbed ionic liquid cations to form an organic and inorganic hybrid film on graphene sheets. The modified electrode was used for the determination of dopamine (DA) in the presence of uric acid (UA). This electrode anticipated the good electron mobility and large surface area of graphene, high ionic conductivity of ionic liquid besides the electron transfer property of phosphomolybdic acid. Optimization of the sensor's performance is presented and resulted in a better current signal. The linear range of the modified electrode was from 0.1-100 μM for determination of DA with an R-Square 0.9924 and with a detection limit of 3.3 × 10 −8 M (S/N = 3). The IL-PMo 12 /RGO/GCE also presented good stability and reproducibility. In the last ten years graphene, a two-dimensional all-sp 2 -hybridized carbon, has received growing research interest as an electrode material due to its large surface area, good chemical stability, high electrical and thermal conductivity and broad electrochemical window.1-5 Nevertheless, graphene usually suffer from serious aggregation caused by van der Waals interactions between the carbon sheets, resulting in reduced active specific surface area for electrochemical performance.6 One of the most common routes to resolve this problem is functionalization of graphene, including reactions of graphene (and its derivatives) with organic and inorganic molecules, chemical modification of the large graphene surface, and the general description of various covalent and noncovalent interactions with graphene.7-9 So far, the most economical way to produce graphene is reduction of graphene oxide (GO). This kind of graphene is also called chemically reduced graphene oxide (RGO), usually has abundant structure defects and functional groups 10,11 which are advantageous for its electrochemical applications.12 Recently, RGO or RGO composite-based modified electrodes have attracted much attention in the field of electrochemical sensors and biosensors, 13 electroanalysis 14 and electrochemical determination of metal ions, 15 et al. Polyoxometalates are Keggin-type heteropolyanions of molybdenum and tungsten, which are particularly attractive because of their ability to adsorb irreversibly on carbon and metal surfaces by selfassembling to form structured films.16 Such polyoxometallates are rigid inorganic metal-oxygen compounds which undergo reversible stepwise multi-electron transfer reactions of importance to such technologies as electrocatalysis, molecular electronics and sensing. [17][18][19] It has been reported that phosphomolybdic acid (H 3 PMo 12 O 48 , PMo 12 ) can form an anionic monolayer on the carbon materials, 20 PMo 12 -functionalization could exfoliate the stacked graphene sheets into individual one...

show abstract

Enhancement of oxygen reduction at Co-porphyrin catalyst by supporting onto hybrid multi-layered film of polypyrrole and polyoxometalate-modified gold nanoparticles

Żołądek

Rutkowska

Blicharska

et al. 2016

J Solid State Electrochem

Self Cite

View full text Add to dashboard Cite

Three-dimensional multi-layered films (on glassy carbon) composed of networks of polyoxometallate (PMo 12 O 40 3− )-modified gold nanoparticles linked together through the alternately deposited ultra-thin layers of polypyrrole have served as active supports for Co-porphyrin catalytic centers. The hybrid organic-inorganic films (supports) have been prepared by using the layer-by-layer approach. The fact that polyanionic (phosphomolybdate) adsorbates on gold nanoparticles are attracted by positively charged sites of conducting polymer (polypyrrole) structures leads to the stabilizing effect and facilitates distribution of Au nanostructures. The systems have been characterized using scanning electron microscopy, as well as with chronoamperometric and voltammetric techniques. By supporting Co-porphyrin centers o n t o t h e h y b r i d f i l m o f t h e p o l y m e r -l i n k e d phosphomolybdate-stabilized gold nanoparticles, significant electrocatalytic enhancement effects (namely voltammetric current increases) have been observed during the electroreduction of oxygen in acid medium relative to a standard response of the simple porphyrin deposit on glassy carbon measured under analogous conditions. Among important issues is the high activity of the hybrid film (support) itself toward the reductive decomposition of hydrogen peroxide to water. When it comes to performance of the Co-porphyrincontaining system, it is reasonable to expect that the O 2 reduction process is initiated at Co-porphyrin catalytic sites (twoelectron reduction to H 2 O 2 ) and continued (two-electron reduction to H 2 O) at the hybrid film containing gold nanoparticles dispersed within the highly porous cauliflower-like structures of polypyrrole multi-layers. While the gold networks facilitate charge distribution within the hybrid electrocatalytic film, non-covalent π-π interactions of porphyrin rings with polypyrrole interlayers and charge transfers between negatively charged (PMo 12 O 40 3− modified) gold nanoparticles and positively charged nitrogen sites of polypyrrole could also cause synergism.

show abstract

Polyoxometallate-assisted integration of nanostructures of Au and ZrO 2 to form supports for electrocatalytic PtRu nanoparticles: enhancement of their activity toward oxidation of ethanol

Cited by 15 publications

References 39 publications

Electroanalysis of Ethanol Oxidation and Reactivity of Platinum-Ruthenium Catalysts Supported onto Nanostructured Titanium Dioxide Matrices

Electroanalysis of Ethanol Oxidation and Reactivity of Platinum-Ruthenium Catalysts Supported onto Nanostructured Titanium Dioxide Matrices

Self-Assembled Ionic Liquid-Phosphomolybdic Acid/Reduced Graphene Oxide Composite Modified Electrode for Sensitive Determination of Dopamine

Enhancement of oxygen reduction at Co-porphyrin catalyst by supporting onto hybrid multi-layered film of polypyrrole and polyoxometalate-modified gold nanoparticles

Contact Info

Product

Resources

About