Enhancement of activity of platinum towards oxidation of ethanol by supporting on titanium dioxide containing phosphomolybdate-modified gold nanoparticles

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

doi:10.1016/j.apsusc.2011.04.080

Cited by 36 publications

(34 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although supporting Pt or PtRu onto Vulcan-conatining ZrO 2 -based matrices leads to higher electrocatalytic surrents (relative to those observed at Vulcan-free systems) [10], our preliminary comparative results clearly show that the electrocatalytic enhancement effect is even more pronounced when polyoxometallate-modified gold nanoparticles [11][12][13][14][15] of Vulcanlike sizes are utilized as carriers. Therefore, we consider here Au nanoc [11][12][13][14][15] lusters that have been intentionally modified and stabilized (protected against agglomeration) with inorganic (heteropolymolybdate or PMo 12 O 40 3À ) polyanions. Contrary to organic capping ligands, the polyoxometallate adsorbates do not act as passivating agents because they are spacious, wellconducting and characterized by fast electron transfers during reversible multi-electron redox transitions [13,16].…”

Section: Introductionmentioning

confidence: 80%

“…Contrary to organic capping ligands, the polyoxometallate adsorbates do not act as passivating agents because they are spacious, wellconducting and characterized by fast electron transfers during reversible multi-electron redox transitions [13,16]. Thus, in the presence of PMo 12 O 40 3À -modified gold nanostructures, the distribution of charge at the electrocatalytic interface should be improved. Further, by analogy to electrostatic interactions of heteropolymolybdate adsorbates (on Pt nanoparticles) with positively charged sites of an organic conducting polymer [17], the PMo 12 O 40 3À anions on gold are likely to attract electrostatically zirconyl oxocationic species that are expected to overcoat ZrO 2 nanostructures in acid medium [6].…”

Section: Introductionmentioning

confidence: 95%

See 1 more Smart Citation

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

Żołądek

Kulesza

2015

Electrochimica Acta

Self Cite

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 80%

Section: Introductionmentioning

confidence: 95%

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

Żołądek

Kulesza

2015

Electrochimica Acta

Self Cite

View full text Add to dashboard Cite

“…The procedure was consistent with the view that controlled amounts of phosphomolybdate-stabilized gold nanoparticles were introduced during alternate immersions. In view of the literature reports [20][21][22][23][24][25][26][27], three sets of highly reversible peaks (Fig. 1a) shall be interpreted in terms of the consecutive two-electron reactions leading to the formation of partially reduced heteropoly blue phosphomolybdates according to the Eq.…”

Section: Resultsmentioning

confidence: 99%

“…The one-step-synthesis of gold nanoparticles stabilized by u l t r a -t h i n s e l f -a s s e m b le d f i l m s of K e gg i n -t yp e phosphomolybdates, which was based on the reaction between partially reduced phosphomolybdate heteropoly blue and the gold precursor (HAuCl 4 ), was described in our previous reports [21][22][23] . Three-dimensional multilayer films composed of six layers of PMo 12 -stabilized gold nanostructures and five ultra-thin layers polypyrrole (6PMo 12 -Au NPs/5PPy) were fabricated using the layer-by-layer method according to the procedure described earlier [17,24,25].…”

Section: Methodsmentioning

confidence: 99%

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

“…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.…”

mentioning

confidence: 99%

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

Enhancement of activity of platinum towards oxidation of ethanol by supporting on titanium dioxide containing phosphomolybdate-modified gold nanoparticles

Cited by 36 publications

References 28 publications

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

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

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

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

Contact Info

Product

Resources

About