The efficiency of methanol conversion to CO2 on thin films of Pt and PtRu fuel cell catalysts

Gao, Lin; Huiliang, Huang; Korzeniewski, Carol

doi:10.1016/j.electacta.2003.07.015

Cited by 46 publications

(33 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These predictions are supported by a number of observations, for instance, by comparing product distributions measured in model studies with those determined at the exhaust of DMFCs or direct ethanol fuel cells (DEFCs) [Wasmus et al, 1995;Sanicharane et al, 2002;Tkach et al, 2004;Seiler et al, 2004;Neergat et al, 2006;Rao et al, 2007], or by comparison of product yields for different electrode roughnesses [Ota et al, 1984], catalyst loadings [Childers et al, 1999;Jusys et al, 2003;Bergamaski et al, 2006;Gavrilov et al, 2007;Islam et al, 2007], reactant concentrations [Wang et al, 2001a;Camara and Iwasita, 2005;Wang et al, 2004], or electrolyte flow rates [Wang et al, 2001a]. Further mechanistic information has come from studies investigating the influence of crystallographic orientation [Wang et al, 2001a;Sun and Clavilier, 1987;Shin et al, 1996;Tarnowski and Korzeniewski, 1997;Sriramulu et al, 1998;Housmans et al, 2006;Nakamura et al, 2007;Spendelow et al, 2007], adsorbed anions [Batista et al, 2003[Batista et al, , 2004, or composition of bimetallic catalysts [Shibata et al, 1987;Jusys et al, 2002a, b;Gao et al, 2004;Islam et al, 2007;Entina et al, 1967;Watanabe and Motoo, 1975;Sun et al, 1988;Gasteiger et al, 1993Gasteiger et al, , 1994Iwasita et al, 1994;…”

Section: # #mentioning

confidence: 99%

Methanol, Formaldehyde, and Formic Acid Adsorption/Oxidation on a Carbon‐Supported Pt Nanoparticle Fuel Cell Catalyst: A Comparative Quantitative DEMS Study

Jusys

Behm

2008

Fuel Cell Catalysis

View full text Add to dashboard Cite

Section: # #mentioning

confidence: 99%

Methanol, Formaldehyde, and Formic Acid Adsorption/Oxidation on a Carbon‐Supported Pt Nanoparticle Fuel Cell Catalyst: A Comparative Quantitative DEMS Study

Jusys

Behm

2008

Fuel Cell Catalysis

View full text Add to dashboard Cite

“…Thus, the current efficiency under convection is increased, as compared to pure Pt. In recent years, extensive studies have increased our knowledge concerning the methanol electrooxidation reaction, and the catalysis of the reaction on different platinum surfaces, including polycrystalline Pt [5,10,[19][20][21][22], Pt(111) [6,10,19,20,23,24], Pt(110) [19,20], Pt(100) [19,20,23], stepped Pt surfaces [6,19] and colloidal nanoparticles [8,9,[25][26][27].…”

Section: Introductionmentioning

confidence: 99%

Methanol Oxidation on Carbon Supported Pt and Ru – Modified Pt Nanoparticles: a Comparison with Single Crystal and Polycrystalline Electrodes

2006

View full text Add to dashboard Cite

The rate of methanol adsorption and oxidation on carbon supported Pt nanoparticles and polycrystalline Pt has been studied by differential electrochemical mass spectrometry (DEMS) under continuous flow. At room temperature, the maximum adsorption rate at polycrystalline Pt is about 0.06 monolayer per second, whereas at Pt nanoparticles it is 0.04 monolayer per second. On polycrystalline Pt it amounts to 56% of a full CO monolayer, obtained by adsorbing CO from a CO saturated electrolyte. On the nanoparticles only 28% of a full CO monolayer can be obtained. The oxidation rate of the adsorbate is of zero order at polycrystalline Pt, whereas at nanoparticles it is of first order with respect to the coverage. Oxidation of methanol starts below the onset of CO2 formation. At polycrystalline Pt and Pt(111), the rate of CO2 formation is determined by the oxidation rate of the adsorbate. At Pt(332) and the nanoparticle electrodes, the rate of CO2 formation from bulk methanol is higher than that from methanol adsorbate, due to the heterogenity of these electrodes.Similarly to Ru modified Pt single crystal electrodes, Ru modified polycrystalline Pt and Pt nanoparticles offer different adsorption sites for CO, which can be selectively populated.

show abstract

“…It also enhances the catalytic properties of Pt via the so called ligand effect, which means it changes the electronic structure of Pt and reduces the Pt-CO bond energy so that the surface diffusion is facilitated [47]. Moreover, selectivity of methanol oxidation to CO2 is very high with PtRu catalyst, more than 95% [58][59][60]. Due to the easily oxidized nature of Ru, its dissolution is one of the main decay mechanisms in DMFC [61], but this can be mitigated with different carbon supports, like carbon nanotubes (CNT) [62] or by nitrogen-doping carbon (N-doped carbon) [63,64].…”

Section: Pt-based Catalysismentioning

confidence: 94%

Silicon nanograss as micro fuel cell gas diffusion layer

et al. 2010

View full text Add to dashboard Cite

Direct methanol fuel cells (DMFC) produce electrical energy directly from chemical energy. They are a promising candidate for power sources of portable devices due to the high energy density of methanol and the quick recharging procedure by fuel insertion. However, the problem areas of the DMFC are the slow electro-oxidation of methanol and the permeated methanol reacting at the cathode. New catalysts are constantly searched but they are often tested only for catalytic activity and the DMFC testing is omitted even though the catalyst layer (CL) structure has a large impact on the performance. Miniaturization of the system is also necessary for portable applications. Silicon etching can be used to fabricate small structures for fuel cells replacing or enhancing the functions of laboratory-scale components.In the first part of this thesis, new catalysts for the DMFC are studied with the emphasis on the CL structure. Different carbon supports for the anode were studied: standard carbon black and alternative few-walled carbon nanotubes (FWCNT) and graphitized carbon nanofiber (GNF). The alternative supports showed better DMFC performance but their stability was lower than with carbon black. However, the CL formed with GNF showed a very porous structure enhancing the mass transfer, so that higher binder content could be used improving the stability to the level of carbon black and the performance by 30%. The FWCNTs were also investigated as a platform for enzymatic methanol oxidation by studying the electrochemical properties of an immobilized cofactor pyrroloquinoline quinone (PQQ). A large amount of PQQ was adsorbed having a strong redox response and good stability in a wide pH window. For the cathode, a methanol-tolerant, Pt-free nitrogen-doped FWCNTs were tested in an alkaline DMFC as such testing is not often made. Its performance was remarkably 4 times better than with Pt when synthetic air was used as the oxidant.In the second part of thesis, an integrated gas diffusion layer (GDL) consisting of Si nanoneedles (nanograss) was tested in a micro fuel cell (MFC). The layer functioned properly at low current densities. For high power applications, a standard carbon cloth GDL was tested with the nanograss as a contact surface reducing the resistance between the GDL and the flow field. The use of the nanograss improved the MFC performance and stability. Finally, the MFCs were used as a catalyst testing platform and the results were compared with a similar test in a laboratory-scale DMFC. The results varied showing that the DMFC components also have a large impact on catalyst testing.Keywords direct methanol fuel cell, carbon nanomaterials, micro fuel cells, catalyst layer Tiivistelmä Suorametanolipolttokennot (SMPK) tuottavat sähköenergiaa suoraan kemiallisesta energiasta. Ne ovat lupaava vaihtoehto kannettavien laitteiden voimanlähteeksi, koska metanolilla on korkea energiatiheys ja lataaminen tapahtuu nopeasti polttoainelisäyksellä. SMPK:lla on kuitenkin rajoitteina metanolin hidas hapetusreaktio ja katodi...

show abstract

The efficiency of methanol conversion to CO2 on thin films of Pt and PtRu fuel cell catalysts

Cited by 46 publications

References 51 publications

Methanol, Formaldehyde, and Formic Acid Adsorption/Oxidation on a Carbon‐Supported Pt Nanoparticle Fuel Cell Catalyst: A Comparative Quantitative DEMS Study

Methanol, Formaldehyde, and Formic Acid Adsorption/Oxidation on a Carbon‐Supported Pt Nanoparticle Fuel Cell Catalyst: A Comparative Quantitative DEMS Study

Methanol Oxidation on Carbon Supported Pt and Ru – Modified Pt Nanoparticles: a Comparison with Single Crystal and Polycrystalline Electrodes

Silicon nanograss as micro fuel cell gas diffusion layer

Contact Info

Product

Resources

About