scholarly journals Highly Enhanced Electrocatalytic Performances with Dendritic Bimetallic Palladium-Based Nanocrystals

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1337
Author(s):  
Respati K. Pramadewandaru ◽  
Jeong-Hu Shim ◽  
Young-Wook Lee ◽  
Jong-Wook Hong
Keyword(s):  
Fuel Cell ◽  
Oxidation Reaction ◽  
Water Electrolysis ◽  
Electrochemical Reactions ◽  
Methanol Oxidation Reaction ◽  
Dense Matrix ◽  
High Porosity ◽  
Pt Catalysts ◽  
Cetyltrimethylammonium Chloride ◽  
Bimetallic Palladium

The exploration of efficient nanocatalysts with high activity and stability towards water electrolysis and fuel cell applications is extremely important for the advancement of electrochemical reactions. However, it remains challenging. Controlling the morphology of bimetallic Pd–Pt nanostructures can be a great way to improve their electrocatalytic properties compared with previously developed catalysts. Herein, we synthesize bimetallic Pd–Pt nanodendrites, which consist of a dense matrix of unsaturated coordination atoms and high porosity. The concentration of cetyltrimethylammonium chloride was significant for the morphology and size of the Pd–Pt nanodendrites. Pd–Pt nanodendrites prepared by cetyltrimethylammonium chloride (200 mM) showed higher activities towards both the hydrogen evolution reaction and methanol oxidation reaction compared to their different Pd–Pt nanodendrite counterparts, commercial Pd, and Pt catalysts, which was attributed to numerous unsaturated surface atoms in well-developed single branches.

scholarly journals Electrochemical Performance Improvement of the Catalyst of the Methanol Micro-Fuel Cell Using Carbon Nanotubes

2019 ◽  
Author(s):  
Mohammad Kazemi Nasrabadi ◽  
Amir Ebrahimi-Moghadam ◽  
Mohammad Hosein Ahmadi ◽  
Ravinder Kumar ◽  
Narjes Nabipour
Keyword(s):  
Carbon Nanotubes ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Carbon Black ◽  
Oxidation Reaction ◽  
High Energy ◽  
Proton Exchange ◽  
Operating Conditions ◽  
High Energy Density ◽  
Methanol Oxidation Reaction

Due to low working temperature, high energy density and low pollution, proton exchange fuel cells have been investigated under different operating conditions in different applications. Using platinum catalysts in methanol fuel cells leads to increasing the cost of this kind of fuel cell which is considered as a barrier to the commercialism of this technology. For this reason, a lot of efforts have been made to reduce the loading of the catalyst required on different supports. In this study, carbon black (CB) and carbon nanotubes (CNT) have been used as catalyst supports of the fuel cell as well as using the double-metal combination of platinum-ruthenium (PtRu) as anode electrode catalyst and platinum (Pt) as cathode electrode catalyst. The performance of these two types of electro-catalyst in the oxidation reaction of methanol has been compared based on electrochemical tests. Results showed that the carbon nanotubes increase the performance of the micro-fuel cell by 37% at maximum power density, compared to the carbon black. Based on thee-electrode tests of chronoamperometry and voltammetry, it was found that the oxidation onset potential of methanol for CNT has been around 20% less than CB, leading to the kinetic improvement of the oxidation reaction. The current density of methanol oxidation reaction increased up to 62% in CNT sample compared to CB supported one, therefore the active electrochemical surface area of the catalyst has been increased up to 90% by using CNT compared to CB which shows the significant rise of the electrocatalytic activity in CNT supported catalyst. Moreover, the resistance of the CNT supported sample to poisonous intermediate species has been found 3% more than CB supported one. According to the chronoamperometry test results, it was concluded that the performance and sustainability of the CNT electro-catalyst show remarkable improvement compared to CB electro-catalyst in the long term.

The Electrolyte-Fuel Concentrations Effects on Direct Methanol Alkaline Fuel Cell (DMAFC) Through Non-Noble Metal Catalysts

2021 ◽  
Vol 5 (1) ◽  
pp. 25
Author(s):  
Wika Atro Auriyani ◽  
Djoni Bustan ◽  
Sri Haryati
Keyword(s):  
Fuel Cell ◽  
Methanol Oxidation ◽  
Current Density ◽  
Potassium Hydroxide ◽  
Oxidation Reaction ◽  
Nickel Foam ◽  
Methanol Oxidation Reaction ◽  
Alkaline Fuel Cell ◽  
Noble Metal Catalysts ◽  
Direct Methanol

Most of the R&D on Direct Methanol Alkaline Fuel Cell (DMAFC) concentrates on electrode catalyst and appropriate electrolyte to improve the efficiency. Mostly, a Pt-based electrocatalyst was used. In this research, Nickel foam and membrane silver as non-noble metal catalysts were used in a square-shaped fuel cell stack of 15 x 15 cm in size. The ionic current in the Direct Methanol Alkaline Fuel Cell (DMAFC) was due to the conduction of hydroxide ions. Potassium hydroxide which plays an essential role in delivering hydroxide ions was used in this study. The electrolyte effect of potassium hydroxide was studied in different concentrations for the methanol oxidation reaction. Nickel foam and membrane silver were used for methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR). 1 M, 3 M, 5 M concentration of potassium hydroxide and 0.5 M, 1 M, 2 M, 3 M, 4 M, 5 M of methanol as a fuel have been conducted. The highest maximum power density of 543.35 mW/cm2 was obtained at 2,331 mA/cm2 of current density using the 5 M KOH and 0,5 M fuel. At equimolar concentration between fuel-electrolyte mixture give the higher current density.

Analysis of Redox Reactions on Pt-Sn based Nano-catalysts for Direct Methanol Fuel Cell Applications

2018 ◽  
Vol 21 (1) ◽  
pp. 021-028 ◽  
Author(s):  
A. Sandoval-González ◽  
S. A. Gamboa
Keyword(s):  
Fuel Cell ◽  
Oxygen Reduction Reaction ◽  
Electric Power ◽  
Oxygen Reduction ◽  
Direct Methanol Fuel Cell ◽  
Oxidation Reaction ◽  
Reduction Reaction ◽  
Methanol Oxidation Reaction ◽  
Direct Methanol ◽  
Methanol Fuel Cell

Low content Pt based catalysts (Pt-Mx, Mx: SnO2, Sn) were prepared by microwave assisted-thermal synthesis. Pt-SnO2/C catalyst showed good performance for methanol oxidation reaction. Besides, Pt1Sn1/C showed good performance for catalyzing the oxygen reduction reaction. The catalysts were characterized structurally by X-ray diffraction and transmission electron microscopy techniques. It was possible to observe the presence of nanoparticles obtained by the synthesis method used in this work. The chemical composition of every material was determined by energy dispersive spectroscopy analysis. The electrochemical characterization of the electrocatalytic materials was carried out in acid medium by cyclic voltammetry and rotating disk electrode techniques. Pt-SnO2/C and Pt1Sn1/C were compared with commercial PtRu/C and Pt/C catalysts respectively. Pt-SnO2/C showed better electrochemical characteristics than commercial PtRu/C for performing the methanol oxidation reaction (MOR). Pt1Sn1/C showed an exchange current density two orders of magnitude higher than commercial Pt/C for performing the oxygen reduction reaction (ORR). The materials were evaluated in an experimental direct methanol fuel cell (DMFC) operating during 10 hours. The electric power density loss showed by the DMFC made with commercial catalysts (PtRu/C and Pt/C) was 67% while the DMFC made with Pt-SnO2/C and Pt1Sn1/C showed an electric power loss ca. 16%. It means that the catalysts synthesized in this work can be considered as good candidates for experimental direct methanol fuel cells.

scholarly journals Electrochemical Performance Improvement of the Catalyst of the Methanol Micro-Fuel Cell Using Carbon Nanotubes

2019 ◽  
Author(s):  
Habib Forootan Fard ◽  
Mohammad Kazemi nasrabadi ◽  
Amir Ebrahimi-Moghadam ◽  
Mohammad Hossein Ahmadi ◽  
Ely Salwana ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Carbon Black ◽  
Oxidation Reaction ◽  
High Energy ◽  
Proton Exchange ◽  
Operating Conditions ◽  
High Energy Density ◽  
Methanol Oxidation Reaction

Due to low working temperature, high energy density and low pollution, proton exchange fuel cells have been investigated under different operating conditions in different applications. Using platinum catalyst in methanol fuel cell leads to increasing the cost of this kind of fuel cells which is considered as a barrier to commercialism of this technology. For this reason, a lot of efforts have been made to reduce the loading of the catalyst required on different supports. In this study, carbon black (CB) and carbon nanotubes (CNT) have been used as catalyst supports of the fuel cell as well as using the double-metal combination of platinum-ruthenium (PtRu) as anode electrode catalyst and platinum (Pt) as cathode electrode catalyst. The performance of these two types of the electro-catalyst in oxidation reaction of methanol has been compared based on electrochemical tests. Results showed that the carbon nanotubes increase the performance of the micro-fuel cell by 37% at maximum power density, compared to the carbon black. Based on thee-electrode tests of chronoamperometry and voltammetry, it was found that oxidation onset potential of methanol for CNT has been around 20% less than CB, leading to the kinetic improvement of the oxidation reaction. In addition, the active electrochemical surface area of catalyst has been increased up to 90% by using CNT compared to CB which shows the significant rise of the electrocatalytic activity in CNT supported catalyst with 62% increase in current density of methanol oxidation reaction respect to CB supported one. Moreover, the resistance of CNT supported sample to poisonous intermediate species has been found 3% more than CB supported one. According to the chronoamperometry test results, it was concluded that the performance and sustainability of NCT electro-catalyst shows remarkable improvement compared to CB electro-catalyst in long term.

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