Catalysts in direct ethanol fuel cell (DEFC): An overview

Akhairi, M. A F; Kamarudin, Siti Kartom

doi:10.1016/j.ijhydene.2015.12.145

Cited by 369 publications

(237 citation statements)

References 63 publications

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“…Due to the need for CC bond breaking for full oxidation of EtOH, EOR often gives low current densities. [54] Our experiments show that G-Cys-Au@Pt gives enhanced catalytic behavior compared to recently reported Pt catalysts, tested in acidic conditions and with 10 times higher EtOH concentration. A plethora of catalysts has been studied for EOR in both acidic and alkaline environments.…”

Section: Oxidation Of Fuel Cell Target Moleculessupporting

confidence: 50%

Tailored Electron Transfer Pathways in Au_core/Pt_shell–Graphene Nanocatalysts for Fuel Cells

Šešelj

Engelbrekt

Ding

et al. 2018

Advanced Energy Materials

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Aucore/Ptshell–graphene catalysts (G‐Cys‐Au@Pt) are prepared through chemical and surface chemical reactions. Au–Pt core–shell nanoparticles (Au@Pt NPs) covalently immobilized on graphene (G) are efficient electrocatalysts in low‐temperature polymer electrolyte membrane fuel cells. The 9.5 ± 2 nm Au@Pt NPs with atomically thin Pt shells are attached on graphene via l‐cysteine (Cys), which serves as linkers controlling NP loading and dispersion, enhancing the Au@Pt NP stability, and facilitating interfacial electron transfer. The increased activity of G‐Cys‐Au@Pt, compared to non‐chemically immobilized G‐Au@Pt and commercial platinum NPs catalyst (C‐Pt), is a result of (1) the tailored electron transfer pathways of covalent bonds integrating Au@Pt NPs into the graphene framework, and (2) synergetic electronic effects of atomically thin Pt shells on Au cores. Enhanced electrocatalytic oxidation of formic acid, methanol, and ethanol is observed as higher specific currents and increased stability of G‐Cys‐Au@Pt compared to G‐Au@Pt and C–Pt. Oxygen reduction on G‐Cys‐Au@Pt occurs at 25 mV lower potential and 43 A gPt−1 higher current (at 0.9 V vs reversible hydrogen electrode) than for C–Pt. Functional tests in direct fomic acid, methanol and ethanol fuel cells exhibit 95%, 53%, and 107% increased power densities for G‐Cys‐Au@Pt over C–Pt, respectively.

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Section: Oxidation Of Fuel Cell Target Moleculessupporting

confidence: 50%

Tailored Electron Transfer Pathways in Au_core/Pt_shell–Graphene Nanocatalysts for Fuel Cells

Šešelj

Engelbrekt

Ding

et al. 2018

Advanced Energy Materials

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“…[1][2][3] However, the C-C bond resists scission and the oxidation of ethanol usually stops at the production of acetic acid, limiting the energy efficiency of this non-toxic alcohol for fuel cell applications.…”

Section: Introductionmentioning

confidence: 99%

Computational screening for selective catalysts: Cleaving the C C bond during ethanol electro-oxidation reaction

Monyoncho

Steinmann

Sautet

et al. 2018

Electrochimica Acta

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The efficiency of direct ethanol fuel cells suffers from the partial oxidation of ethanol into acetic acid as opposed to the complete oxidation of this fuel to CO 2 . Herein, we support the quest for a selective catalyst for ethanol electro-oxidation to CO 2 , building on our previous mechanistic hypothesis based on experimental insight and DFT computations. We derive a simple descriptor of the expected selectivity towards full oxidation, Ω, as a function of the adsorption energy of atomic C and O. Three different families of catalyst surfaces are screened using this descriptor: monometallics, bimetallics and conducting metal oxides, totaling to 600 surfaces. In agreement with available experimental data, no single metal surface is more selective for total oxidation than platinum and palladium. While the selected conducting oxides were not predicted to be selective towards splitting the C-C bond, structurally-controlled monometallics (such as Pd (100)) or some bimetallics (Pd 3 Ag) are found to be competitive with the most stable facet, (111), of Pd and Pt. Despite this very extensive screening, no very promising catalyst has been identified. This highlights the need to identify catalysts for acetate oxidation or to exploit support effects and electrolyte engineering to profit from the full power of direct ethanol fuel cells.

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“…This produces a sharp reduction of the effective catalyst surface area, which also reduces cell performance [25,[40][41][42]. To mitigate this effect, binary Pt-based catalysts include a secondary metal, such as Sn or Ru [42][43][44][45][46][47][48][49][50][51][52]; the blockage of active sites is alleviated via a bifunctional mechanism that allows the absorption of hydroxyl groups at lower potentials on the secondary metal, thus favoring further oxidation of Pt-adsorbates blocking the active catalyst sites [53][54][55]. It is interesting to note that the problem of CO poisoning is not unique to DAFCs; low-temperature PEMFCs running on hydrogen have very low tolerance to impurities (e.g., CO) in the fuel, requiring very high purity hydrogen that is costly to produce.…”

Section: Direct Alcohol Pem Fuel Cellsmentioning

confidence: 99%

“…Due to the multiple species involved, the reaction is slower and more complex than Reaction (3), which leads to significantly lower current densities in DMFCs than in hydrogen PEMFCs. As a result, complex and expensive catalyst compositions (Pt-Ru nanoparticles supported on high surface area carbon) must be used to minimize activation losses [42][43][44][45][46][47][48][49][50][51][52].…”

Section: Redox Pairsmentioning

confidence: 99%

Fundamentals of Electrochemistry with Application to Direct Alcohol Fuel Cell Modeling

Sánchez-Monreal¹,

Vera²,

García-Salaberri³

2018

Proton Exchange Membrane Fuel Cell

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Fuel cell modeling is an inherently multiphysics problem. As a result, scientists and engineers trained in different areas are required to work together in this field to address the complex physicochemical phenomena involved in the design and optimization of fuel cell systems. This multidisciplinary approach forces researchers to become accustomed to new concepts. Electrochemical processes, for example, constitute the heart of a fuel cell. Accurate modeling of electrochemical reactions is therefore essential to successfully predict the performance of these devices. However, becoming familiar with the complex concepts of electrochemistry can be an arduous task for those who approach the study of fuel cells from fields other than chemical engineering. This process can extend over time and requires careful reading of many textbooks and papers, the most illuminating ones being hidden to the newcomer in a plethora of recent publications on the subject. The authors, who engaged in the study of fuel cells coming from the field of mechanical engineering, had to travel this road once and, with this contribution, would like to make the journey easier for those who come behind. As an illustrative example, the thermodynamic and electrochemical principles reviewed in this chapter are applied to a complex electrochemical system, the direct ethanol fuel cell (DEFC), reviewing recent work on this problem and suggesting future research directions.

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Catalysts in direct ethanol fuel cell (DEFC): An overview

Cited by 369 publications

References 63 publications

Tailored Electron Transfer Pathways in Au_core/Pt_shell–Graphene Nanocatalysts for Fuel Cells

Tailored Electron Transfer Pathways in Au_core/Pt_shell–Graphene Nanocatalysts for Fuel Cells

Computational screening for selective catalysts: Cleaving the C C bond during ethanol electro-oxidation reaction

Fundamentals of Electrochemistry with Application to Direct Alcohol Fuel Cell Modeling

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Catalysts in direct ethanol fuel cell (DEFC): An overview

Cited by 369 publications

References 63 publications

Tailored Electron Transfer Pathways in Aucore/Ptshell–Graphene Nanocatalysts for Fuel Cells

Tailored Electron Transfer Pathways in Aucore/Ptshell–Graphene Nanocatalysts for Fuel Cells

Computational screening for selective catalysts: Cleaving the C C bond during ethanol electro-oxidation reaction

Fundamentals of Electrochemistry with Application to Direct Alcohol Fuel Cell Modeling

Contact Info

Product

Resources

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Tailored Electron Transfer Pathways in Au_core/Pt_shell–Graphene Nanocatalysts for Fuel Cells

Tailored Electron Transfer Pathways in Au_core/Pt_shell–Graphene Nanocatalysts for Fuel Cells