scholarly journals Comparison of Single-Walled and Multiwalled Carbon Nanotubes Durability as Pt Support in Gas Diffusion Electrodes

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mehdi Asgari ◽  
Elaheh Lohrasbi

Durability of single-walled (SWCNT) and multiwalled carbon nanotubes (MWCNT) as Pt supports was studied using two accelerated durability tests (ADTs), potential cycling and potentiostatic treatment. ADT of gas diffusion electrodes (GDEs) was once studied during the potential cycling. Pt surface area loss with increasing the potential cycling numbers for GDE using SWCNT was shown to be higher than that for GDE using MWCNT. In addition, equilibrium concentrations of dissolved Pt species from GDEs in 1.0 M H2SO4 were found to be increased with increasing the potential cycling numbers. Both findings suggest that Pt detachment from support surface plays an important role in Pt surface loss in proton exchange membrane fuel cell electrodes. ADT of GDEs was also studied following the potentiostatic treatments up to 24 h under the following conditions: argon purged, 1.0 M H2SO4, 60°C, and a constant potential of 0.9 V. The subsequent electrochemical characterization suggests that GDE that uses MWCNT/Pt is electrochemically more stable than other GDE using SWCNT/Pt. As a result of high corrosion resistance, GDE that uses MWCNT/Pt shows lower loss of Pt surface area and oxygen reduction reaction activity when used as fuel cell catalyst. The results also showed that potential cycling accelerates the rate of surface area loss.

Author(s):  
Yulia Plekhanova ◽  
Sergey Tarasov ◽  
Vladimir Kolesov ◽  
Iren Kuznetsova ◽  
Maria Signore ◽  
...  

The anode of a microbial fuel cell (MFC) was formed on a graphite electrode and immobilized Gluconobacter oxydans VKM-1280 bacterial cells. Immobilization was performed in chitosan, poly(vinyl alcohol) or N-vinylpyrrolidone-modified poly(vinyl alcohol). Ethanol was used as substrate. The anode was modified using multiwalled carbon nanotubes. The aim of the modification was to create a conductive network between cell lipid membranes, containing exposed PQQ-dependent alcoholdehydrogenases, and the electrode to facilitate electron transfer in the system. The bioelectrochemical characteristics of modified anodes at various cell/polymer ratios were assessed via current density, power density, polarization curves and impedance spectres. MFCs based on chitosan at a matrix/cell volume ratio of 5:1 produced maximal power characteristics of the system (8.3 μW/cm2) at a minimal resistance (1111 Ohm cm2). Modification of the anode by multiwalled carbon nanotubes led to a slight decrease of internal resistance (down to 1078 Ohm cm2) and to an increase of generated power density up to 10.6 μW/cm2. We explored the possibility of accumulating electric energy from an MFC on a 6,800-μF capacitor via a boost converter. Generated voltage was increased from 0.3 V up to 3.2 V. Accumulated energy was used to power a Clark-type biosensor and a bluetooth transmitter with three sensors, a miniature electric motor and a light-emitting diode.


2015 ◽  
Vol 22 (3) ◽  
pp. 647-658 ◽  
Author(s):  
Rajangam Padmavathi ◽  
Ammaiappan Sandhya Devi ◽  
Neelakandan Saranya ◽  
Periyannan Gnanasundaram ◽  
Dharmalingam Sangeetha

Membranes ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 99 ◽  
Author(s):  
Yulia Plekhanova ◽  
Sergei Tarasov ◽  
Vladimir Kolesov ◽  
Iren Kuznetsova ◽  
Maria Signore ◽  
...  

The anode of a microbial fuel cell (MFC) was formed on a graphite electrode and immobilized Gluconobacter oxydans VKM-1280 bacterial cells. Immobilization was performed in chitosan, poly(vinyl alcohol) or N-vinylpyrrolidone-modified poly(vinyl alcohol). Ethanol was used as substrate. The anode was modified using multiwalled carbon nanotubes. The aim of the modification was to create a conductive network between cell lipid membranes, containing exposed pyrroloquinoline quinone (PQQ)-dependent alcoholdehydrogenases, and the electrode to facilitate electron transfer in the system. The bioelectrochemical characteristics of modified anodes at various cell/polymer ratios were assessed via current density, power density, polarization curves and impedance spectres. Microbial fuel cells based on chitosan at a matrix/cell volume ratio of 5:1 produced maximal power characteristics of the system (8.3 μW/cm2) at a minimal resistance (1111 Ohm cm2). Modification of the anode by multiwalled carbon nanotubes (MWCNT) led to a slight decrease of internal resistance (down to 1078 Ohm cm2) and to an increase of generated power density up to 10.6 μW/cm2. We explored the possibility of accumulating electric energy from an MFC on a 6800-μF capacitor via a boost converter. Generated voltage was increased from 0.3 V up to 3.2 V. Accumulated energy was used to power a Clark-type biosensor and a Bluetooth transmitter with three sensors, a miniature electric motor and a light-emitting diode.


Energy ◽  
2016 ◽  
Vol 109 ◽  
pp. 446-455 ◽  
Author(s):  
M. Beltrán-Gastélum ◽  
M.I. Salazar-Gastélum ◽  
R.M. Félix-Navarro ◽  
S. Pérez-Sicairos ◽  
E.A. Reynoso-Soto ◽  
...  

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